Land #384: Pluggable Transport and HTTP transport modules

.circleci/config.yml

@@ -296,7 +296,7 @@ jobs:
           name: Scan explorer_web for vulnerabilities
           command: mix sobelow --config
           working_directory: "apps/explorer_web"
-  test_geth:
+  test_geth_http:
     docker:
       # Ensure .tool-versions matches
       - image: circleci/elixir:1.6.5-node-browsers
@@ -306,7 +306,10 @@ jobs:
           PGPASSWORD: postgres
           # match POSTGRES_USER for postgres image below
           PGUSER: postgres
-          ETHEREUM_JSONRPC_VARIANT: geth
+          ETHEREUM_JSONRPC_VARIANT: "EthereumJSONRPC.Geth"
+          ETHEREUM_JSONRPC_TRANSPORT: "EthereumJSONRPC.HTTP"
+          ETHEREUM_JSONRPC_HTTP: "EthereumJSONRPC.HTTP.HTTPoison"
+          ETHEREUM_JSONRPC_HTTP_URL: "https://mainnet.infura.io/8lTvJTKmHPCHazkneJsY"
       - image: circleci/postgres:10.3-alpine
         environment:
           # Match apps/explorer/config/test.exs config :explorerer, Explorer.Repo, database
@@ -333,7 +336,7 @@ jobs:
 
       - store_test_results:
           path: _build/test/junit
-  test_parity:
+  test_geth_mox:
     docker:
       # Ensure .tool-versions matches
       - image: circleci/elixir:1.6.5-node-browsers
@@ -343,7 +346,8 @@ jobs:
           PGPASSWORD: postgres
           # match POSTGRES_USER for postgres image below
           PGUSER: postgres
-          ETHEREUM_JSONRPC_VARIANT: parity
+          ETHEREUM_JSONRPC_VARIANT: "EthereumJSONRPC.Geth"
+          ETHEREUM_JSONRPC_TRANSPORT: "EthereumJSONRPC.Mox"
       - image: circleci/postgres:10.3-alpine
         environment:
           # Match apps/explorer/config/test.exs config :explorerer, Explorer.Repo, database
@@ -366,7 +370,86 @@ jobs:
           name: Wait for DB
           command: dockerize -wait tcp://localhost:5432 -timeout 1m
 
-      - run: mix coveralls.circle --parallel --umbrella
+      - run: mix coveralls.circle --exclude no_geth --parallel --umbrella
+
+      - store_test_results:
+          path: _build/test/junit
+  test_parity_http:
+    docker:
+      # Ensure .tool-versions matches
+      - image: circleci/elixir:1.6.5-node-browsers
+        environment:
+          MIX_ENV: test
+          # match POSTGRES_PASSWORD for postgres image below
+          PGPASSWORD: postgres
+          # match POSTGRES_USER for postgres image below
+          PGUSER: postgres
+          ETHEREUM_JSONRPC_VARIANT: "EthereumJSONRPC.Parity"
+          # enable on-chain tests against Sokol instead of `mox` tests run locally
+          ETHEREUM_JSONRPC_TRANSPORT: "EthereumJSONRPC.HTTP"
+          ETHEREUM_JSONRPC_HTTP: "EthereumJSONRPC.HTTP.HTTPoison"
+          ETHEREUM_JSONRPC_HTTP_URL: "https://sokol-trace.poa.network"
+      - image: circleci/postgres:10.3-alpine
+        environment:
+          # Match apps/explorer/config/test.exs config :explorer, Explorer.Repo, database
+          POSTGRES_DB: explorer_test
+          # match PGPASSWORD for elixir image above
+          POSTGRES_PASSWORD: postgres
+          # match PGUSER for elixir image above
+          POSTGRES_USER: postgres
+
+    working_directory: ~/app
+
+    steps:
+      - attach_workspace:
+          at: .
+
+      - run: mix local.hex --force
+      - run: mix local.rebar --force
+
+      - run:
+          name: Wait for DB
+          command: dockerize -wait tcp://localhost:5432 -timeout 1m
+
+      - run: mix coveralls.circle --exclude no_parity --parallel --umbrella
+
+      - store_test_results:
+          path: _build/test/junit
+  test_parity_mox:
+    docker:
+      # Ensure .tool-versions matches
+      - image: circleci/elixir:1.6.5-node-browsers
+        environment:
+          MIX_ENV: test
+          # match POSTGRES_PASSWORD for postgres image below
+          PGPASSWORD: postgres
+          # match POSTGRES_USER for postgres image below
+          PGUSER: postgres
+          ETHEREUM_JSONRPC_VARIANT: "EthereumJSONRPC.Parity"
+          ETHEREUM_JSONRPC_TRANSPORT: "EthereumJSONRPC.Mox"
+      - image: circleci/postgres:10.3-alpine
+        environment:
+          # Match apps/explorer/config/test.exs config :explorer, Explorer.Repo, database
+          POSTGRES_DB: explorer_test
+          # match PGPASSWORD for elixir image above
+          POSTGRES_PASSWORD: postgres
+          # match PGUSER for elixir image above
+          POSTGRES_USER: postgres
+
+    working_directory: ~/app
+
+    steps:
+      - attach_workspace:
+          at: .
+
+      - run: mix local.hex --force
+      - run: mix local.rebar --force
+
+      - run:
+          name: Wait for DB
+          command: dockerize -wait tcp://localhost:5432 -timeout 1m
+
+      - run: mix coveralls.circle --exclude no_parity --parallel --umbrella
 
       - store_test_results:
           path: _build/test/junit
@@ -394,8 +477,10 @@ workflows:
             - eslint
             - jest
             - sobelow
-            - test_parity
+            - test_parity_http
-            - test_geth
+            - test_parity_mox
+            - test_geth_http
+            - test_geth_mox
       - dialyzer:
           requires:
             - build
@@ -411,9 +496,15 @@ workflows:
       - sobelow:
           requires:
             - build
-      - test_parity:
+      - test_parity_http:
+          requires:
+            - build
+      - test_parity_mox:
+          requires:
+            - build
+      - test_geth_http:
           requires:
             - build
-      - test_geth:
+      - test_geth_mox:
           requires:
             - build

apps/ethereum_jsonrpc/README.md

@@ -20,6 +20,17 @@ via `:trace_url`. The trace URL and is used for
 tracing nodes. The `:http` option is passed directly to the HTTP
 library (`HTTPoison`), which forwards the options down to `:hackney`.
 
+## Testing
+
+By default, [`mox`](https://github.com/plataformatec/mox) will be used to mock the `EthereumJSONRPC.Transport` and `EthereumJSONRPC.HTTP` behaviours.  They mocked behaviours returns differ based on the `EthereumJSONRPC.Variant`.
+
+| `EthereumJSONRPC.Variant` | `EthereumJSONRPC.Transport` | `EthereumJSONRPC.HTTP`           | `url`                                             | Command                                                                                                                                                                                                                                                  | Usage(s)                                           |
+|:--------------------------|:----------------------------|:---------------------------------|:--------------------------------------------------|:---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|:---------------------------------------------------|
+| `EthereumJSONRPC.Parity`  | `EthereumJSONRPC.Mox`       | `EthereumJSONRPC.HTTP.Mox`       | N/A                                               | `mix test`                                                                                                                                                                                                                                               | Local, `circleci/config.yml` `test_parity_mox` job |
+| `EthereumJSONRPC.Parity`  | `EthereumJSONRPC.HTTP`      | `EthereumJSONRPC.HTTP.HTTPoison` | `https://trace-sokol.poa.network`                 | `ETHEREUM_JSONRPC_VARIANT=EthereumJSONRPC.Parity ETHEREUM_JSONRPC_TRANSPORT=EthereumJSONRPC.HTTP ETHEREUM_JSONRPC_HTTP=EthereumJSONRPC.HTTP.HTTPoison ETHEREUM_JSONRPC_HTTP_URL=https://sokol-trace.poa.network mix test --exclude no_parity`            | `.circleci/config.yml` `test_parity_http` job      |
+| `EthereumJSONRPC.Geth`    | `EthereumJSONRPC.Mox`       | `EthereumJSONRPC.HTTP.Mox`       | N/A                                               | `ETHEREUM_JSONRPC_VARIANT=EthereumJSONRPC.Geth mix test --exclude no_geth`                                                                                                                                                                               | `.circleci/config.yml` `test_geth_http` job        |
+| `EthereumJSONRPC.Geth`    | `EthereumJSONRPC.HTTP`      | `EthereumJSONRPC.HTTP.HTTPoison` | `https://mainnet.infura.io/8lTvJTKmHPCHazkneJsY`  | `ETHEREUM_JSONRPC_VARIANT=EthereumJSONRPC.Geth ETHEREUM_JSONRPC_TRANSPORT=EthereumJSONRPC.HTTP ETHEREUM_JSONRPC_HTTP=EthereumJSONRPC.HTTP.HTTPoison ETHEREUM_JSONRPC_HTTP_URL=https://mainnet.infura.io/8lTvJTKmHPCHazkneJsY mix test --exclude no_geth` | `.circleci/config.yml` `test_geth_http` job        |
+
 ## Installation
 
 The OTP application `:ethereum_jsonrpc` can be used in other umbrella

apps/ethereum_jsonrpc/config/config.exs

@@ -1,12 +0,0 @@
-# This file is responsible for configuring your application
-# and its dependencies with the aid of the Mix.Config module.
-use Mix.Config
-
-config :ethereum_jsonrpc,
-  http: [recv_timeout: 60_000, timeout: 60_000, hackney: [pool: :ethereum_jsonrpc]]
-
-variant = System.get_env("ETHEREUM_JSONRPC_VARIANT") || "parity"
-
-# Import variant specific config. This must remain at the bottom
-# of this file so it overrides the configuration defined above.
-import_config "#{variant}.exs"

apps/ethereum_jsonrpc/config/geth.exs

@@ -1,5 +0,0 @@
-use Mix.Config
-
-config :ethereum_jsonrpc,
-  url: "https://mainnet.infura.io/8lTvJTKmHPCHazkneJsY",
-  variant: EthereumJSONRPC.Geth

apps/ethereum_jsonrpc/config/parity.exs

@@ -1,9 +0,0 @@
-use Mix.Config
-
-config :ethereum_jsonrpc,
-  url: "https://sokol.poa.network",
-  method_to_url: [
-    eth_getBalance: "https://sokol-trace.poa.network",
-    trace_replayTransaction: "https://sokol-trace.poa.network"
-  ],
-  variant: EthereumJSONRPC.Parity

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc.ex

@@ -16,10 +16,8 @@ defmodule EthereumJSONRPC do
   directly to the HTTP library (`HTTPoison`), which forwards the options down to `:hackney`.
   """
 
-  require Logger
-
   alias Explorer.Chain.Block
-  alias EthereumJSONRPC.{Blocks, Receipts, Transactions}
+  alias EthereumJSONRPC.{Blocks, Receipts, Transactions, Transport, Variant}
 
   @typedoc """
   Truncated 20-byte [KECCAK-256](https://en.wikipedia.org/wiki/SHA-3) hash encoded as a hexadecimal number in a
@@ -42,6 +40,18 @@ defmodule EthereumJSONRPC do
   """
   @type hash :: String.t()
 
+  @typedoc """
+  Named arguments to `json_rpc/2`.
+
+   * `:transport` - the `t:EthereumJSONRPC.Transport.t/0` callback module
+   * `:transport_options` - options passed to `c:EthereumJSONRPC.Transport.json_rpc/2`
+   * `:variant` - the `t:EthereumJSONRPC.Variant.t/0` callback module
+
+  """
+  @type json_rpc_named_arguments :: [
+          {:transport, Transport.t()} | {:transport_options, Transport.options()} | {:variant, Variant.t()}
+        ]
+
   @typedoc """
   8 byte [KECCAK-256](https://en.wikipedia.org/wiki/SHA-3) hash of the proof-of-work.
   """
@@ -73,47 +83,13 @@ defmodule EthereumJSONRPC do
   """
   @type timestamp :: String.t()
 
-  @doc """
-  Fetches configuration for this module under `key`
-
-  Configuration can be set a compile time using `config`
-
-      config :ethereume_jsonrpc, key, value
-
-  Configuration can be set a runtime using `Application.put_env/3`
-
-      Application.put_env(:ethereume_jsonrpc, key, value)
-
-  """
-  def config(key) do
-    Application.fetch_env!(:ethereum_jsonrpc, key)
-  end
-
-  @doc """
-  Fetches the configured url for the specific `method` or the fallback `url`
-
-  Configuration for a specific `method` can be set in `method_to_url` `config`
-
-      config :ethereum_jsonrpc,
-        method_to_url: [
-          eth_getBalance: "method_to_url"
-        ]
-
-  The fallback 'url' MUST we set if not all methods have a url set.
-
-      config :ethereum_jsonrpc,
-        url:
-  """
-  def method_to_url(method) when is_atom(method) do
-    :ethereum_jsonrpc
-    |> Application.get_env(:method_to_url, [])
-    |> Keyword.get_lazy(method, fn -> config(:url) end)
-  end
-
   @doc """
   Fetches balance for each address `hash` at the `block_number`
   """
-  @spec fetch_balances([%{required(:block_quantity) => quantity, required(:hash_data) => data()}]) ::
+  @spec fetch_balances(
+          [%{required(:block_quantity) => quantity, required(:hash_data) => data()}],
+          json_rpc_named_arguments
+        ) ::
           {:ok,
            [
              %{
@@ -123,13 +99,14 @@ defmodule EthereumJSONRPC do
              }
            ]}
           | {:error, reason :: term}
-  def fetch_balances(params_list) when is_list(params_list) do
+  def fetch_balances(params_list, json_rpc_named_arguments)
+      when is_list(params_list) and is_list(json_rpc_named_arguments) do
     id_to_params = id_to_params(params_list)
 
     with {:ok, responses} <-
            id_to_params
            |> get_balance_requests()
-           |> json_rpc(method_to_url(:eth_getBalance)) do
+           |> json_rpc(json_rpc_named_arguments) do
       get_balance_responses_to_addresses_params(responses, id_to_params)
     end
   end
@@ -139,10 +116,10 @@ defmodule EthereumJSONRPC do
 
   Transaction data is included for each block.
   """
-  def fetch_blocks_by_hash(block_hashes) do
+  def fetch_blocks_by_hash(block_hashes, json_rpc_named_arguments) do
     block_hashes
     |> get_block_by_hash_requests()
-    |> json_rpc(method_to_url(:eth_getBlockByHash))
+    |> json_rpc(json_rpc_named_arguments)
     |> handle_get_blocks()
     |> case do
       {:ok, _next, results} -> {:ok, results}
@@ -153,10 +130,10 @@ defmodule EthereumJSONRPC do
   @doc """
   Fetches blocks by block number range.
   """
-  def fetch_blocks_by_range(_first.._last = range) do
+  def fetch_blocks_by_range(_first.._last = range, json_rpc_named_arguments) do
     range
     |> get_block_by_number_requests()
-    |> json_rpc(method_to_url(:eth_getBlockByNumber))
+    |> json_rpc(json_rpc_named_arguments)
     |> handle_get_blocks()
   end
 
@@ -170,33 +147,40 @@ defmodule EthereumJSONRPC do
    * `{:error, reason}` - other JSONRPC error.
 
   """
-  @spec fetch_block_number_by_tag(tag()) :: {:ok, non_neg_integer()} | {:error, reason :: :invalid_tag | term()}
+  @spec fetch_block_number_by_tag(tag(), json_rpc_named_arguments) ::
-  def fetch_block_number_by_tag(tag) when tag in ~w(earliest latest pending) do
+          {:ok, non_neg_integer()} | {:error, reason :: :invalid_tag | term()}
+  def fetch_block_number_by_tag(tag, json_rpc_named_arguments) when tag in ~w(earliest latest pending) do
     tag
     |> get_block_by_tag_request()
-    |> json_rpc(method_to_url(:eth_getBlockByNumber))
+    |> json_rpc(json_rpc_named_arguments)
     |> handle_get_block_by_tag()
   end
 
   @doc """
   Fetches internal transactions from variant API.
   """
-  def fetch_internal_transactions(params_list) when is_list(params_list) do
+  def fetch_internal_transactions(params_list, json_rpc_named_arguments) when is_list(params_list) do
-    config(:variant).fetch_internal_transactions(params_list)
+    Keyword.fetch!(json_rpc_named_arguments, :variant).fetch_internal_transactions(
+      params_list,
+      json_rpc_named_arguments
+    )
   end
 
   @doc """
   Fetches pending transactions from variant API.
   """
-  def fetch_pending_transactions do
+  def fetch_pending_transactions(json_rpc_named_arguments) do
-    config(:variant).fetch_pending_transactions()
+    Keyword.fetch!(json_rpc_named_arguments, :variant).fetch_pending_transactions(json_rpc_named_arguments)
   end
 
-  @spec fetch_transaction_receipts([
+  @spec fetch_transaction_receipts(
+          [
             %{required(:gas) => non_neg_integer(), required(:hash) => hash, optional(atom) => any}
-        ]) :: {:ok, %{logs: list(), receipts: list()}} | {:error, reason :: term}
+          ],
-  def fetch_transaction_receipts(transactions_params) when is_list(transactions_params) do
+          json_rpc_named_arguments
-    Receipts.fetch(transactions_params)
+        ) :: {:ok, %{logs: list(), receipts: list()}} | {:error, reason :: term}
+  def fetch_transaction_receipts(transactions_params, json_rpc_named_arguments) when is_list(transactions_params) do
+    Receipts.fetch(transactions_params, json_rpc_named_arguments)
   end
 
   @doc """
@@ -218,26 +202,15 @@ defmodule EthereumJSONRPC do
     * Handled response
     * `{:error, reason}` if POST failes
   """
-  def json_rpc(payload, url) when is_list(payload) do
+  @spec json_rpc(Transport.request(), json_rpc_named_arguments) ::
-    chunked_json_rpc(url, [payload], config(:http), [])
+          {:ok, Transport.result()} | {:error, reason :: term()}
-  end
+  @spec json_rpc(Transport.batch_request(), json_rpc_named_arguments) ::
+          {:ok, Transport.batch_response()} | {:error, reason :: term()}
+  def json_rpc(request, named_arguments) when (is_map(request) or is_list(request)) and is_list(named_arguments) do
+    transport = Keyword.fetch!(named_arguments, :transport)
+    transport_options = Keyword.fetch!(named_arguments, :transport_options)
 
-  def json_rpc(payload, url) do
+    transport.json_rpc(request, transport_options)
-    json = encode_json(payload)
-
-    case post(url, json, config(:http)) do
-      {:ok, %HTTPoison.Response{body: body, status_code: status_code}} ->
-        with {:ok, json} <-
-               decode_json(
-                 request: [url: url, body: json],
-                 response: [status_code: status_code, body: body]
-               ) do
-          handle_response(json, status_code)
-        end
-
-      {:error, %HTTPoison.Error{reason: reason}} ->
-        {:error, reason}
-    end
   end
 
   @doc """
@@ -267,14 +240,10 @@ defmodule EthereumJSONRPC do
   @doc """
   A request payload for a JSONRPC.
   """
-  @spec request(%{id: term, method: String.t(), params: list()}) :: %{String.t() => term}
+  @spec request(%{id: non_neg_integer(), method: String.t(), params: list()}) :: Transport.request()
-  def request(%{id: id, method: method, params: params}) do
+  def request(%{id: id, method: method, params: params} = map)
-    %{
+      when is_integer(id) and is_binary(method) and is_list(params) do
-      "id" => id,
+    Map.put(map, :jsonrpc, "2.0")
-      "jsonrpc" => "2.0",
-      "method" => method,
-      "params" => params
-    }
   end
 
   @doc """
@@ -286,52 +255,6 @@ defmodule EthereumJSONRPC do
     |> Timex.from_unix()
   end
 
-  defp chunked_json_rpc(_url, [], _options, decoded_response_bodies) when is_list(decoded_response_bodies) do
-    list =
-      decoded_response_bodies
-      |> Enum.reverse()
-      |> List.flatten()
-
-    {:ok, list}
-  end
-
-  defp chunked_json_rpc(url, [batch | tail] = chunks, options, decoded_response_bodies)
-       when is_list(batch) and is_list(tail) and is_list(decoded_response_bodies) do
-    json = encode_json(batch)
-
-    case post(url, json, options) do
-      {:ok, %HTTPoison.Response{status_code: 413} = response} ->
-        rechunk_json_rpc(url, chunks, options, response, decoded_response_bodies)
-
-      {:ok, %HTTPoison.Response{body: body, status_code: status_code}} ->
-        with {:ok, decoded_body} <-
-               decode_json(request: [url: url, body: json], response: [status_code: status_code, body: body]) do
-          chunked_json_rpc(url, tail, options, [decoded_body | decoded_response_bodies])
-        end
-
-      {:error, %HTTPoison.Error{reason: reason}} ->
-        {:error, reason}
-    end
-  end
-
-  defp rechunk_json_rpc(url, [batch | tail], options, response, decoded_response_bodies) do
-    case length(batch) do
-      # it can't be made any smaller
-      1 ->
-        Logger.error(fn ->
-          "413 Request Entity Too Large returned from single request batch.  Cannot shrink batch further."
-        end)
-
-        {:error, response}
-
-      batch_size ->
-        split_size = div(batch_size, 2)
-        {first_chunk, second_chunk} = Enum.split(batch, split_size)
-        new_chunks = [first_chunk, second_chunk | tail]
-        chunked_json_rpc(url, new_chunks, options, decoded_response_bodies)
-    end
-  end
-
   defp get_balance_requests(id_to_params) when is_map(id_to_params) do
     Enum.map(id_to_params, fn {id, %{block_quantity: block_quantity, hash_data: hash_data}} ->
       get_balance_request(%{id: id, block_quantity: block_quantity, hash_data: hash_data})
@@ -367,7 +290,7 @@ defmodule EthereumJSONRPC do
     {status, Enum.reverse(reversed)}
   end
 
-  defp get_balance_response_to_address_params(%{"id" => id, "result" => fetched_balance_quantity}, id_to_params)
+  defp get_balance_response_to_address_params(%{id: id, result: fetched_balance_quantity}, id_to_params)
        when is_map(id_to_params) do
     %{block_quantity: block_quantity, hash_data: hash_data} = Map.fetch!(id_to_params, id)
 
@@ -379,11 +302,11 @@ defmodule EthereumJSONRPC do
      }}
   end
 
-  defp get_balance_response_to_address_params(%{"id" => id, "error" => error}, id_to_params)
+  defp get_balance_response_to_address_params(%{id: id, error: error}, id_to_params)
        when is_map(id_to_params) do
     %{block_quantity: block_quantity, hash_data: hash_data} = Map.fetch!(id_to_params, id)
 
-    annotated_error = Map.merge(error, %{"blockNumber" => block_quantity, "hash" => hash_data})
+    annotated_error = Map.put(error, :data, %{"blockNumber" => block_quantity, "hash" => hash_data})
 
     {:error, annotated_error}
   end
@@ -414,7 +337,7 @@ defmodule EthereumJSONRPC do
 
   defp get_block_by_tag_request(tag) do
     # eth_getBlockByNumber accepts either a number OR a tag
-    get_block_by_number_request(%{id: 1, tag: tag, transactions: :hashes})
+    get_block_by_number_request(%{id: 0, tag: tag, transactions: :hashes})
   end
 
   defp get_block_by_number_params(options) do
@@ -444,34 +367,11 @@ defmodule EthereumJSONRPC do
     end
   end
 
-  defp encode_json(data), do: Jason.encode_to_iodata!(data)
-
-  defp decode_json(named_arguments) when is_list(named_arguments) do
-    response = Keyword.fetch!(named_arguments, :response)
-    response_body = Keyword.fetch!(response, :body)
-
-    with {:error, _} <- Jason.decode(response_body) do
-      case Keyword.fetch!(response, :status_code) do
-        # CloudFlare protected server return HTML errors for 502, so the JSON decode will fail
-        502 ->
-          request_url =
-            named_arguments
-            |> Keyword.fetch!(:request)
-            |> Keyword.fetch!(:url)
-
-          {:error, {:bad_gateway, request_url}}
-
-        _ ->
-          raise EthereumJSONRPC.DecodeError, named_arguments
-      end
-    end
-  end
-
   defp handle_get_blocks({:ok, results}) do
     {blocks, next} =
       Enum.reduce(results, {[], :more}, fn
-        %{"result" => nil}, {blocks, _} -> {blocks, :end_of_chain}
+        %{result: nil}, {blocks, _} -> {blocks, :end_of_chain}
-        %{"result" => %{} = block}, {blocks, next} -> {[block | blocks], next}
+        %{result: %{} = block}, {blocks, next} -> {[block | blocks], next}
       end)
 
     elixir_blocks = Blocks.to_elixir(blocks)
@@ -494,19 +394,4 @@ defmodule EthereumJSONRPC do
 
   defp handle_get_block_by_tag({:error, %{"code" => -32602}}), do: {:error, :invalid_tag}
   defp handle_get_block_by_tag({:error, _} = error), do: error
-
-  defp handle_response(resp, 200) do
-    case resp do
-      %{"error" => error} -> {:error, error}
-      %{"result" => result} -> {:ok, result}
-    end
-  end
-
-  defp handle_response(resp, _status) do
-    {:error, resp}
-  end
-
-  defp post(url, json, options) do
-    HTTPoison.post(url, json, [{"Content-Type", "application/json"}], options)
-  end
 end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/geth.ex

@@ -8,27 +8,17 @@ defmodule EthereumJSONRPC.Geth do
   @doc """
   Internal transaction fetching is not supported currently for Geth.
 
-  To signal to the caller that fetching is not supported, `:ignore` is returned
+  To signal to the caller that fetching is not supported, `:ignore` is returned.
-
-      iex> EthereumJSONRPC.Geth.fetch_internal_transactions([
-      ...>   "0x2ec382949ba0b22443aa4cb38267b1fb5e68e188109ac11f7a82f67571a0adf3"
-      ...> ])
-      :ignore
-
   """
   @impl EthereumJSONRPC.Variant
-  def fetch_internal_transactions(transaction_params) when is_list(transaction_params),
+  def fetch_internal_transactions(transaction_params, _json_rpc_named_arguments) when is_list(transaction_params),
     do: :ignore
 
   @doc """
   Pending transaction fetching is not supported currently for Geth.
 
-  To signal to the caller that fetching is not supported, `:ignore` is returned
+  To signal to the caller that fetching is not supported, `:ignore` is returned.
-
-      iex> EthereumJSONRPC.Geth.fetch_pending_transactions()
-      :ignore
-
   """
   @impl EthereumJSONRPC.Variant
-  def fetch_pending_transactions, do: :ignore
+  def fetch_pending_transactions(_json_rpc_named_arguments), do: :ignore
 end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/http.ex

@@ -0,0 +1,171 @@
+defmodule EthereumJSONRPC.HTTP do
+  @moduledoc """
+  JSONRPC over HTTP
+  """
+
+  alias EthereumJSONRPC.Transport
+
+  require Logger
+
+  @behaviour Transport
+
+  @callback json_rpc(url :: String.t(), json :: iodata(), options :: term()) ::
+              {:ok, %{body: body :: String.t(), status_code: status_code :: pos_integer()}}
+              | {:error, reason :: term}
+
+  @impl Transport
+
+  def json_rpc(%{method: method} = request, options) when is_map(request) do
+    json = encode_json(request)
+    http = Keyword.fetch!(options, :http)
+    url = url(options, method)
+    http_options = Keyword.fetch!(options, :http_options)
+
+    with {:ok, %{body: body, status_code: code}} <- http.json_rpc(url, json, http_options),
+         {:ok, json} <- decode_json(request: [url: url, body: json], response: [status_code: code, body: body]) do
+      handle_response(json, code)
+    end
+  end
+
+  def json_rpc(batch_request, options) when is_list(batch_request) do
+    chunked_json_rpc([batch_request], options, [])
+  end
+
+  defp chunked_json_rpc([], _options, decoded_response_bodies) when is_list(decoded_response_bodies) do
+    list =
+      decoded_response_bodies
+      |> Enum.reverse()
+      |> List.flatten()
+      |> Enum.map(&standardize_response/1)
+
+    {:ok, list}
+  end
+
+  # JSONRPC 2.0 standard says that an empty batch (`[]`) returns an empty response (`""`), but an empty response isn't
+  # valid JSON, so instead act like it returns an empty list (`[]`)
+  defp chunked_json_rpc([[] | tail], options, decoded_response_bodies) do
+    chunked_json_rpc(tail, options, decoded_response_bodies)
+  end
+
+  defp chunked_json_rpc([[%{method: method} | _] = batch | tail] = chunks, options, decoded_response_bodies)
+       when is_list(tail) and is_list(decoded_response_bodies) do
+    http = Keyword.fetch!(options, :http)
+    url = url(options, method)
+    http_options = Keyword.fetch!(options, :http_options)
+
+    json = encode_json(batch)
+
+    case http.json_rpc(url, json, http_options) do
+      {:ok, %{status_code: 413} = response} ->
+        rechunk_json_rpc(chunks, options, response, decoded_response_bodies)
+
+      {:ok, %{body: body, status_code: status_code}} ->
+        with {:ok, decoded_body} <-
+               decode_json(request: [url: url, body: json], response: [status_code: status_code, body: body]) do
+          chunked_json_rpc(tail, options, [decoded_body | decoded_response_bodies])
+        end
+
+      {:error, _} = error ->
+        error
+    end
+  end
+
+  defp rechunk_json_rpc([batch | tail], options, response, decoded_response_bodies) do
+    case length(batch) do
+      # it can't be made any smaller
+      1 ->
+        Logger.error(fn ->
+          "413 Request Entity Too Large returned from single request batch.  Cannot shrink batch further."
+        end)
+
+        {:error, response}
+
+      batch_size ->
+        split_size = div(batch_size, 2)
+        {first_chunk, second_chunk} = Enum.split(batch, split_size)
+        new_chunks = [first_chunk, second_chunk | tail]
+        chunked_json_rpc(new_chunks, options, decoded_response_bodies)
+    end
+  end
+
+  defp encode_json(data), do: Jason.encode_to_iodata!(data)
+
+  defp decode_json(named_arguments) when is_list(named_arguments) do
+    response = Keyword.fetch!(named_arguments, :response)
+    response_body = Keyword.fetch!(response, :body)
+
+    with {:error, _} <- Jason.decode(response_body) do
+      case Keyword.fetch!(response, :status_code) do
+        # CloudFlare protected server return HTML errors for 502, so the JSON decode will fail
+        502 ->
+          request_url =
+            named_arguments
+            |> Keyword.fetch!(:request)
+            |> Keyword.fetch!(:url)
+
+          {:error, {:bad_gateway, request_url}}
+
+        _ ->
+          raise EthereumJSONRPC.DecodeError, named_arguments
+      end
+    end
+  end
+
+  defp handle_response(resp, 200) do
+    case resp do
+      %{"error" => error} -> {:error, standardize_error(error)}
+      %{"result" => result} -> {:ok, result}
+    end
+  end
+
+  defp handle_response(resp, _status) do
+    {:error, resp}
+  end
+
+  # restrict response to only those fields supported by the JSON-RPC 2.0 standard, which means that level of keys is
+  # validated, so we can indicate that with switch to atom keys.
+  defp standardize_response(%{"jsonrpc" => "2.0" = jsonrpc, "id" => id} = unstandardized) when is_integer(id) do
+    standardized = %{jsonrpc: jsonrpc, id: id}
+
+    case unstandardized do
+      %{"result" => _, "error" => _} ->
+        raise ArgumentError,
+              "result and error keys are mutually exclusive in JSONRPC 2.0 response objects, but got #{unstandardized}"
+
+      %{"result" => result} ->
+        Map.put(standardized, :result, result)
+
+      %{"error" => error} ->
+        Map.put(standardized, :error, standardize_error(error))
+    end
+  end
+
+  # restrict error to only those fields supported by the JSON-RPC 2.0 standard, which means that level of keys is
+  # validated, so we can indicate that with switch to atom keys.
+  defp standardize_error(%{"code" => code, "message" => message} = unstandardized)
+       when is_integer(code) and is_binary(message) do
+    standardized = %{code: code, message: message}
+
+    case Map.fetch(unstandardized, "data") do
+      {:ok, data} -> Map.put(standardized, :data, data)
+      :error -> standardized
+    end
+  end
+
+  defp url(options, method) when is_list(options) and is_binary(method) do
+    with {:ok, method_to_url} <- Keyword.fetch(options, :method_to_url),
+         {:ok, method_atom} <- to_existing_atom(method),
+         {:ok, url} <- Keyword.fetch(method_to_url, method_atom) do
+      url
+    else
+      _ -> Keyword.fetch!(options, :url)
+    end
+  end
+
+  defp to_existing_atom(string) do
+    {:ok, String.to_existing_atom(string)}
+  rescue
+    ArgumentError ->
+      :error
+  end
+end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/http/httpoison.ex

@@ -0,0 +1,20 @@
+defmodule EthereumJSONRPC.HTTP.HTTPoison do
+  @moduledoc """
+  Uses `HTTPoison` for `EthereumJSONRPC.HTTP`
+  """
+
+  alias EthereumJSONRPC.HTTP
+
+  @behaviour HTTP
+
+  @impl HTTP
+  def json_rpc(url, json, options) when is_binary(url) and is_list(options) do
+    case HTTPoison.post(url, json, [{"Content-Type", "application/json"}], options) do
+      {:ok, %HTTPoison.Response{body: body, status_code: status_code}} ->
+        {:ok, %{body: body, status_code: status_code}}
+
+      {:error, %HTTPoison.Error{reason: reason}} ->
+        {:error, reason}
+    end
+  end
+end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/parity.ex

@@ -3,7 +3,7 @@ defmodule EthereumJSONRPC.Parity do
   Ethereum JSONRPC methods that are only supported by [Parity](https://wiki.parity.io/).
   """
 
-  import EthereumJSONRPC, only: [id_to_params: 1, method_to_url: 1, json_rpc: 2, request: 1]
+  import EthereumJSONRPC, only: [id_to_params: 1, json_rpc: 2, request: 1]
 
   alias EthereumJSONRPC.Parity.Traces
   alias EthereumJSONRPC.{Transaction, Transactions}
@@ -14,13 +14,13 @@ defmodule EthereumJSONRPC.Parity do
   Fetches the `t:Explorer.Chain.InternalTransaction.changeset/2` params from the Parity trace URL.
   """
   @impl EthereumJSONRPC.Variant
-  def fetch_internal_transactions(transactions_params) when is_list(transactions_params) do
+  def fetch_internal_transactions(transactions_params, json_rpc_named_arguments) when is_list(transactions_params) do
     id_to_params = id_to_params(transactions_params)
 
     with {:ok, responses} <-
            id_to_params
            |> trace_replay_transaction_requests()
-           |> json_rpc(method_to_url(:trace_replayTransaction)) do
+           |> json_rpc(json_rpc_named_arguments) do
       trace_replay_transaction_responses_to_internal_transactions_params(responses, id_to_params)
     end
   end
@@ -32,12 +32,13 @@ defmodule EthereumJSONRPC.Parity do
   on the transactions that each node has seen and how each node prioritizes collating transactions into the next block.
   """
   @impl EthereumJSONRPC.Variant
-  @spec fetch_pending_transactions() :: {:ok, [Transaction.params()]} | {:error, reason :: term}
+  @spec fetch_pending_transactions(EthereumJSONRPC.json_rpc_named_arguments()) ::
-  def fetch_pending_transactions do
+          {:ok, [Transaction.params()]} | {:error, reason :: term}
+  def fetch_pending_transactions(json_rpc_named_arguments) do
     with {:ok, transactions} <-
            %{id: 1, method: "parity_pendingTransactions", params: []}
            |> request()
-           |> json_rpc(method_to_url(:parity_pendingTransactions)) do
+           |> json_rpc(json_rpc_named_arguments) do
       transactions_params =
         transactions
         |> Transactions.to_elixir()
@@ -94,7 +95,7 @@ defmodule EthereumJSONRPC.Parity do
     end
   end
 
-  defp trace_replay_transaction_response_to_traces(%{"id" => id, "result" => %{"trace" => traces}}, id_to_params)
+  defp trace_replay_transaction_response_to_traces(%{id: id, result: %{"trace" => traces}}, id_to_params)
        when is_list(traces) and is_map(id_to_params) do
     %{block_number: block_number, hash_data: transaction_hash} = Map.fetch!(id_to_params, id)
 
@@ -108,11 +109,11 @@ defmodule EthereumJSONRPC.Parity do
     {:ok, annotated_traces}
   end
 
-  defp trace_replay_transaction_response_to_traces(%{"id" => id, "error" => error}, id_to_params)
+  defp trace_replay_transaction_response_to_traces(%{id: id, error: error}, id_to_params)
        when is_map(id_to_params) do
     %{block_number: block_number, hash_data: transaction_hash} = Map.fetch!(id_to_params, id)
 
-    annotated_error = Map.merge(error, %{"blockNumber" => block_number, "transactionHash" => transaction_hash})
+    annotated_error = Map.put(error, :data, %{"blockNumber" => block_number, "transactionHash" => transaction_hash})
 
     {:error, annotated_error}
   end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/parity/trace.ex

@@ -245,7 +245,11 @@ defmodule EthereumJSONRPC.Parity.Trace do
 
   def elixir_to_params(%{"type" => "suicide" = type} = elixir) do
     %{
-      "action" => %{"address" => from_address_hash, "balance" => value, "refundAddress" => to_address_hash},
+      "action" => %{
+        "address" => from_address_hash,
+        "balance" => value,
+        "refundAddress" => to_address_hash
+      },
       "blockNumber" => block_number,
       "index" => index,
       "traceAddress" => trace_address,
@@ -406,23 +410,28 @@ defmodule EthereumJSONRPC.Parity.Trace do
 
   """
 
-  def to_elixir(%{"blockNumber" => _, "index" => _, "transactionHash" => _} = trace) when is_map(trace) do
+  def to_elixir(%{"blockNumber" => _, "index" => _, "transactionHash" => _} = trace)
+      when is_map(trace) do
     Enum.into(trace, %{}, &entry_to_elixir/1)
   end
 
   def to_elixir(_) do
-    raise ArgumentError, ~S|Caller must `Map.put/2` `"blockNumber"`, `"index"`, and `"transactionHash"` in trace|
+    raise ArgumentError,
+          ~S|Caller must `Map.put/2` `"blockNumber"`, `"index"`, and `"transactionHash"` in trace|
   end
 
   # subtraces is an actual integer in JSON and not hex-encoded
   # traceAddress is a list of actual integers, not a list of hex-encoded
-  defp entry_to_elixir({key, _} = entry) when key in ~w(subtraces traceAddress transactionHash type output), do: entry
+  defp entry_to_elixir({key, _} = entry)
+       when key in ~w(subtraces traceAddress transactionHash type output),
+       do: entry
 
   defp entry_to_elixir({"action" = key, action}) do
     {key, Action.to_elixir(action)}
   end
 
-  defp entry_to_elixir({"blockNumber", block_number} = entry) when is_integer(block_number), do: entry
+  defp entry_to_elixir({"blockNumber", block_number} = entry) when is_integer(block_number),
+    do: entry
 
   defp entry_to_elixir({"error", reason} = entry) when is_binary(reason), do: entry
 
@@ -432,7 +441,9 @@ defmodule EthereumJSONRPC.Parity.Trace do
     {key, Result.to_elixir(result)}
   end
 
-  defp put_call_error_or_result(params, %{"result" => %{"gasUsed" => gas_used, "output" => output}}) do
+  defp put_call_error_or_result(params, %{
+         "result" => %{"gasUsed" => gas_used, "output" => output}
+       }) do
     Map.merge(params, %{gas_used: gas_used, output: output})
   end
 
@@ -441,7 +452,11 @@ defmodule EthereumJSONRPC.Parity.Trace do
   end
 
   defp put_create_error_or_result(params, %{
-         "result" => %{"address" => created_contract_address_hash, "code" => code, "gasUsed" => gas_used}
+         "result" => %{
+           "address" => created_contract_address_hash,
+           "code" => code,
+           "gasUsed" => gas_used
+         }
        }) do
     Map.merge(params, %{
       created_contract_code: code,

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/parity/trace/action.ex

@@ -44,7 +44,9 @@ defmodule EthereumJSONRPC.Parity.Trace.Action do
     Enum.into(action, %{}, &entry_to_elixir/1)
   end
 
-  defp entry_to_elixir({key, _} = entry) when key in ~w(address callType from init input refundAddress to), do: entry
+  defp entry_to_elixir({key, _} = entry)
+       when key in ~w(address callType from init input refundAddress to),
+       do: entry
 
   defp entry_to_elixir({key, quantity}) when key in ~w(balance gas value) do
     {key, quantity_to_integer(quantity)}

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/receipts.ex

@@ -5,7 +5,7 @@ defmodule EthereumJSONRPC.Receipts do
   requests.
   """
 
-  import EthereumJSONRPC, only: [config: 1, json_rpc: 2]
+  import EthereumJSONRPC, only: [json_rpc: 2, request: 1]
 
   alias EthereumJSONRPC.{Logs, Receipt}
 
@@ -111,14 +111,17 @@ defmodule EthereumJSONRPC.Receipts do
     Enum.map(elixir, &Receipt.elixir_to_params/1)
   end
 
-  @spec fetch([
+  @spec fetch(
+          [
             %{
               required(:gas) => non_neg_integer(),
               required(:hash) => EthereumJSONRPC.hash(),
               optional(atom) => any
             }
-        ]) :: {:ok, %{logs: list(), receipts: list()}} | {:error, reason :: term}
+          ],
-  def fetch(transactions_params) when is_list(transactions_params) do
+          EthereumJSONRPC.json_rpc_named_arguments()
+        ) :: {:ok, %{logs: list(), receipts: list()}} | {:error, reason :: term()}
+  def fetch(transactions_params, json_rpc_named_arguments) when is_list(transactions_params) do
     {requests, id_to_transaction_params} =
       transactions_params
       |> Stream.with_index()
@@ -129,10 +132,7 @@ defmodule EthereumJSONRPC.Receipts do
         {requests, id_to_transaction_params}
       end)
 
-    requests
+    with {:ok, responses} <- json_rpc(requests, json_rpc_named_arguments) do
-    |> json_rpc(config(:url))
-    |> case do
-      {:ok, responses} ->
       elixir_receipts =
         responses
         |> responses_to_receipts(id_to_transaction_params)
@@ -143,9 +143,6 @@ defmodule EthereumJSONRPC.Receipts do
       logs = Logs.elixir_to_params(elixir_logs)
 
       {:ok, %{logs: logs, receipts: receipts}}
-
-      {:error, _reason} = err ->
-        err
     end
   end
 
@@ -216,17 +213,16 @@ defmodule EthereumJSONRPC.Receipts do
   end
 
   defp request(id, transaction_hash) when is_integer(id) and is_binary(transaction_hash) do
-    %{
+    request(%{
-      "id" => id,
+      id: id,
-      "jsonrpc" => "2.0",
+      method: "eth_getTransactionReceipt",
-      "method" => "eth_getTransactionReceipt",
+      params: [transaction_hash]
-      "params" => [transaction_hash]
+    })
-    }
   end
 
-  defp response_to_receipt(%{"result" => nil}, _), do: %{}
+  defp response_to_receipt(%{result: nil}, _), do: %{}
 
-  defp response_to_receipt(%{"id" => id, "result" => receipt}, id_to_transaction_params) do
+  defp response_to_receipt(%{id: id, result: receipt}, id_to_transaction_params) do
     gas =
       id_to_transaction_params
       |> Map.fetch!(id)

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/transport.ex

@@ -0,0 +1,79 @@
+defmodule EthereumJSONRPC.Transport do
+  @moduledoc """
+  The transport over which JSONRPC calls occur.
+
+  Various clients support the transports below:
+
+   * HTTP
+   * IPC
+   * WS
+
+  """
+
+  @typedoc @moduledoc
+  @type t :: module
+
+  @typedoc """
+  The name of the JSONRPC method
+  """
+  @type method :: String.t()
+
+  @typedoc """
+  [JSONRPC request object](https://www.jsonrpc.org/specification#request_object)
+
+   * `:jsonrpc` - a `t:String.t/0` specifying the JSONR-RPC protocol version.  MUST be exactly `"2.0"`
+   * `:method` - a `t:String.t/0` containing the name of the method to be invoked.
+   * `:params` - a `t:list/0` for the positional parameters for the `"method"`.
+   * `:id` - a `non_neg_integer` that is unique for in a `t:batch_request/0`.
+
+  """
+  @type request :: %{jsonrpc: String.t(), method: method, params: list(), id: non_neg_integer()}
+
+  @typedoc """
+  A batch of `t:request/0`.  Each `t:request/0` in the batch must have a unique `"id"`.
+  """
+  @type batch_request :: [request]
+
+  @type result :: term()
+
+  @typedoc """
+  [JSONRPC response object](https://www.jsonrpc.org/specification#response_object)
+
+  ## Result
+
+   * `:jsonrpc` - a `t:String.t/0` specifying the JSONR-RPC protocol version.  MUST be exactly `"2.0"`
+   * `:result` - the successful result of the request
+   * `:id` - the `"id'` of the `t:request/0` that correlates with this response
+
+  ## Error
+
+   * `:jsonrpc` - a `t:String.t/0` specifying the JSONR-RPC protocol version.  MUST be exactly `"2.0"`
+   * `:error:` - the `t:error/0`
+   * `:id` - the `"id'` of the `t:request/0` that correlates with this response
+
+  """
+  @type response ::
+          %{jsonrpc: String.t(), result: result, id: non_neg_integer()}
+          | %{jsonrpc: String.t(), error: error, id: non_neg_integer()}
+
+  @typedoc """
+  [JSONRPC error object](https://www.jsonrpc.org/specification#error_object)
+
+   * `:code` - an `t:integer/0` indicating the error type
+   * `:message` -
+  """
+  @type error :: %{required(:code) => integer(), required(:message) => String.t(), optional(:data) => term()}
+
+  @typedoc """
+  A batch of `t:response/0`.  Each `t:response/0` will have an `"id"` corresponding to the `"id"` in the `t:request/0`.
+  """
+  @type batch_response :: [response]
+
+  @typedoc """
+  Transport-specific options
+  """
+  @type options :: term()
+
+  @callback json_rpc(request, options) :: {:ok, result} | {:error, reason :: term()}
+  @callback json_rpc(batch_request, options) :: {:ok, batch_response} | {:error, reason :: term()}
+end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/variant.ex

@@ -6,6 +6,11 @@ defmodule EthereumJSONRPC.Variant do
 
   alias EthereumJSONRPC.Transaction
 
+  @typedoc """
+  A module that implements the `EthereumJSONRPC.Variant` behaviour callbacks.
+  """
+  @type t :: module
+
   @type internal_transaction_params :: map()
 
   @doc """
@@ -18,7 +23,7 @@ defmodule EthereumJSONRPC.Variant do
        internal transactions
    * `:ignore` - the variant does not support fetching internal transactions.
   """
-  @callback fetch_internal_transactions([Transaction.params()]) ::
+  @callback fetch_internal_transactions([Transaction.params()], EthereumJSONRPC.json_rpc_named_arguments()) ::
               {:ok, [internal_transaction_params]} | {:error, reason :: term} | :ignore
 
   @doc """
@@ -31,5 +36,6 @@ defmodule EthereumJSONRPC.Variant do
    * `{:error, reason}` - there was one or more errors with `reason` in fetching the pending transactions
    * `:ignore` - the variant does not support fetching pending transactions.
   """
-  @callback fetch_pending_transactions() :: {:ok, [Transaction.params()]} | {:error, reason :: term} | :ignore
+  @callback fetch_pending_transactions(EthereumJSONRPC.json_rpc_named_arguments()) ::
+              {:ok, [Transaction.params()]} | {:error, reason :: term} | :ignore
 end

apps/ethereum_jsonrpc/mix.exs

@@ -69,6 +69,8 @@ defmodule EthereumJsonrpc.MixProject do
       {:httpoison, "~> 1.0", override: true},
       # Decode/Encode JSON for JSONRPC
       {:jason, "~> 1.0"},
+      # Mocking `EthereumJSONRPC.Transport` and `EthereumJSONRPC.HTTP` so we avoid hitting real chains for local testing
+      {:mox, "~> 0.3.2", only: [:test]},
       # Convert unix timestamps in JSONRPC to DateTimes
       {:timex, "~> 3.1.24"}
     ]

apps/ethereum_jsonrpc/test/etheream_jsonrpc_test.exs

@@ -1,71 +1,133 @@
 defmodule EthereumJSONRPCTest do
-  use ExUnit.Case, async: true
+  use EthereumJSONRPC.Case, async: true
 
   import EthereumJSONRPC.Case
+  import Mox
+
+  setup :verify_on_exit!
 
   @moduletag :capture_log
 
-  setup do
+  describe "fetch_balances/1" do
-    %{variant: EthereumJSONRPC.config(:variant)}
+    test "with all valid hash_data returns {:ok, addresses_params}", %{
+      json_rpc_named_arguments: json_rpc_named_arguments
+    } do
+      expected_fetched_balance =
+        case Keyword.fetch!(json_rpc_named_arguments, :variant) do
+          EthereumJSONRPC.Geth -> 0
+          EthereumJSONRPC.Parity -> 1
+          variant -> raise ArgumentError, "Unsupported variant (#{variant}})"
         end
 
-  describe "fetch_balances/1" do
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
-    test "with all valid hash_data returns {:ok, addresses_params}", %{variant: variant} do
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn _json, _options ->
-      assert {:ok,
+          {:ok, [%{id: 0, result: EthereumJSONRPC.integer_to_quantity(expected_fetched_balance)}]}
+        end)
+      end
+
+      hash = "0x8bf38d4764929064f2d4d3a56520a76ab3df415b"
+
+      assert EthereumJSONRPC.fetch_balances(
+               [
+                 %{block_quantity: "0x1", hash_data: hash}
+               ],
+               json_rpc_named_arguments
+             ) ==
+               {:ok,
                 [
                   %{
-                  fetched_balance: fetched_balance,
+                    fetched_balance: expected_fetched_balance,
                     fetched_balance_block_number: 1,
-                  hash: "0x8bf38d4764929064f2d4d3a56520a76ab3df415b"
+                    hash: hash
                   }
-              ]} =
+                ]}
-               EthereumJSONRPC.fetch_balances([
-                 %{block_quantity: "0x1", hash_data: "0x8bf38d4764929064f2d4d3a56520a76ab3df415b"}
-               ])
-
-      case variant do
-        EthereumJSONRPC.Geth ->
-          assert fetched_balance == 0
-
-        EthereumJSONRPC.Parity ->
-          assert fetched_balance == 1
-
-        _ ->
-          raise ArgumentError, "Unsupported variant (#{variant}})"
-      end
     end
 
-    test "with all invalid hash_data returns {:error, reasons}", %{variant: variant} do
+    test "with all invalid hash_data returns {:error, reasons}", %{json_rpc_named_arguments: json_rpc_named_arguments} do
-      assert {:error, reasons} = EthereumJSONRPC.fetch_balances([%{block_quantity: "0x1", hash_data: "0x0"}])
+      variant = Keyword.fetch!(json_rpc_named_arguments, :variant)
-      assert is_list(reasons)
-      assert length(reasons) == 1
-
-      [reason] = reasons
-
-      assert %{
-               "blockNumber" => "0x1",
-               "code" => -32602,
-               "hash" => "0x0",
-               "message" => message
-             } = reason
 
+      expected_message =
         case variant do
           EthereumJSONRPC.Geth ->
-          assert message ==
             "invalid argument 0: json: cannot unmarshal hex string of odd length into Go value of type common.Address"
 
           EthereumJSONRPC.Parity ->
-          assert message ==
             "Invalid params: invalid length 1, expected a 0x-prefixed, padded, hex-encoded hash with length 40."
 
           _ ->
             raise ArgumentError, "Unsupported variant (#{variant}})"
         end
+
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn _json, _options ->
+          {:ok,
+           [
+             %{
+               id: 0,
+               error: %{
+                 code: -32602,
+                 message: expected_message
+               }
+             }
+           ]}
+        end)
+      end
+
+      assert {:error,
+              [
+                %{
+                  code: -32602,
+                  data: %{"blockNumber" => "0x1", "hash" => "0x0"},
+                  message: ^expected_message
+                }
+              ]} =
+               EthereumJSONRPC.fetch_balances([%{block_quantity: "0x1", hash_data: "0x0"}], json_rpc_named_arguments)
+    end
+
+    test "with a mix of valid and invalid hash_data returns {:error, reasons}", %{
+      json_rpc_named_arguments: json_rpc_named_arguments
+    } do
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn _json, _options ->
+          {
+            :ok,
+            [
+              %{
+                id: 0,
+                result: "0x0"
+              },
+              %{
+                id: 1,
+                result: "0x1"
+              },
+              %{
+                id: 2,
+                error: %{
+                  code: -32602,
+                  message:
+                    "Invalid params: invalid length 1, expected a 0x-prefixed, padded, hex-encoded hash with length 40."
+                }
+              },
+              %{
+                id: 3,
+                result: "0x3"
+              },
+              %{
+                id: 4,
+                error: %{
+                  code: -32602,
+                  message:
+                    "Invalid params: invalid length 1, expected a 0x-prefixed, padded, hex-encoded hash with length 40."
+                }
+              }
+            ]
+          }
+        end)
       end
 
-    test "with a mix of valid and invalid hash_data returns {:error, reasons}" do
       assert {:error, reasons} =
-               EthereumJSONRPC.fetch_balances([
+               EthereumJSONRPC.fetch_balances(
+                 [
                    # start with :ok
                    %{
                      block_quantity: "0x1",
@@ -91,18 +153,26 @@ defmodule EthereumJSONRPCTest do
                      block_quantity: "0x4",
                      hash_data: "0x5"
                    }
-               ])
+                 ],
+                 json_rpc_named_arguments
+               )
 
       assert is_list(reasons)
       assert length(reasons) > 1
     end
   end
 
-  describe "fetch_block_number_by_tag/1" do
+  describe "fetch_block_number_by_tag" do
     @tag capture_log: false
-    test "with earliest" do
+    test "with earliest", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn _json, _options ->
+          {:ok, %{"number" => "0x0"}}
+        end)
+      end
+
       log_bad_gateway(
-        fn -> EthereumJSONRPC.fetch_block_number_by_tag("earliest") end,
+        fn -> EthereumJSONRPC.fetch_block_number_by_tag("earliest", json_rpc_named_arguments) end,
         fn result ->
           assert {:ok, 0} = result
         end
@@ -110,9 +180,15 @@ defmodule EthereumJSONRPCTest do
     end
 
     @tag capture_log: false
-    test "with latest" do
+    test "with latest", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn _json, _options ->
+          {:ok, %{"number" => "0x1"}}
+        end)
+      end
+
       log_bad_gateway(
-        fn -> EthereumJSONRPC.fetch_block_number_by_tag("latest") end,
+        fn -> EthereumJSONRPC.fetch_block_number_by_tag("latest", json_rpc_named_arguments) end,
         fn result ->
           assert {:ok, number} = result
           assert number > 0
@@ -121,9 +197,15 @@ defmodule EthereumJSONRPCTest do
     end
 
     @tag capture_log: false
-    test "with pending" do
+    test "with pending", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn _json, _options ->
+          {:ok, %{"number" => "0x2"}}
+        end)
+      end
+
       log_bad_gateway(
-        fn -> EthereumJSONRPC.fetch_block_number_by_tag("pending") end,
+        fn -> EthereumJSONRPC.fetch_block_number_by_tag("pending", json_rpc_named_arguments) end,
         fn result ->
           assert {:ok, number} = result
           assert number > 0

apps/ethereum_jsonrpc/test/ethereum_jsonrpc/geth_test.exs

@@ -1,5 +1,24 @@
 defmodule EthereumJSONRPC.GethTest do
-  use ExUnit.Case, async: false
+  use EthereumJSONRPC.Case, async: false
 
-  doctest EthereumJSONRPC.Geth
+  alias EthereumJSONRPC.Geth
+
+  @moduletag :no_parity
+
+  describe "fetch_internal_transactions/2" do
+    test "is not supported", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+      Geth.fetch_internal_transactions(
+        [
+          "0x2ec382949ba0b22443aa4cb38267b1fb5e68e188109ac11f7a82f67571a0adf3"
+        ],
+        json_rpc_named_arguments
+      )
+    end
+  end
+
+  describe "fetch_pending_transactions/1" do
+    test "is not supported", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+      EthereumJSONRPC.Geth.fetch_pending_transactions(json_rpc_named_arguments)
+    end
+  end
 end

apps/ethereum_jsonrpc/test/ethereum_jsonrpc/http/mox_test.exs

@@ -0,0 +1,121 @@
+defmodule EthereumJSONRPC.HTTP.MoxTest do
+  @moduledoc """
+  Tests differences in behavior of `EthereumJSONRPC` when `EthereumJSONRPC.HTTP` is used as the transport that are too
+  detrimental to run against Sokol, so uses `EthereumJSONRPC.HTTP.Mox` instead.
+  """
+
+  use ExUnit.Case, async: true
+
+  import EthereumJSONRPC, only: [request: 1]
+  import EthereumJSONRPC.HTTP.Case
+  import Mox
+
+  setup do
+    %{
+      json_rpc_named_arguments: [
+        transport: EthereumJSONRPC.HTTP,
+        transport_options: [
+          http: EthereumJSONRPC.HTTP.Mox,
+          url: url(),
+          http_options: http_options()
+        ]
+      ]
+    }
+  end
+
+  setup :verify_on_exit!
+
+  describe "json_rpc/2" do
+    # regression test for https://github.com/poanetwork/poa-explorer/issues/254
+    #
+    # this test triggered a DoS with CloudFlare reporting 502 Bad Gateway
+    # (see https://github.com/poanetwork/poa-explorer/issues/340), so it can't be run against the real Sokol chain and
+    # must use `mox` to fake it.
+    test "transparently splits batch payloads that would trigger a 413 Request Entity Too Large", %{
+      json_rpc_named_arguments: json_rpc_named_arguments
+    } do
+      if json_rpc_named_arguments[:transport_options][:http] == EthereumJSONRPC.HTTP.Mox do
+        EthereumJSONRPC.HTTP.Mox
+        |> expect(:json_rpc, 2, fn _url, json, _options ->
+          assert IO.iodata_to_binary(json) =~ ":13000"
+
+          {:ok, %{body: "413 Request Entity Too Large", status_code: 413}}
+        end)
+        |> expect(:json_rpc, fn _url, json, _options ->
+          json_binary = IO.iodata_to_binary(json)
+
+          refute json_binary =~ ":13000"
+          assert json_binary =~ ":6499"
+
+          body =
+            0..6499
+            |> Enum.map(fn id ->
+              %{jsonrpc: "2.0", id: id, result: %{number: EthereumJSONRPC.integer_to_quantity(id)}}
+            end)
+            |> Jason.encode!()
+
+          {:ok, %{body: body, status_code: 200}}
+        end)
+        |> expect(:json_rpc, fn _url, json, _optons ->
+          json_binary = IO.iodata_to_binary(json)
+
+          refute json_binary =~ ":6499"
+          assert json_binary =~ ":6500"
+          assert json_binary =~ ":13000"
+
+          body =
+            6500..13000
+            |> Enum.map(fn id ->
+              %{jsonrpc: "2.0", id: id, result: %{number: EthereumJSONRPC.integer_to_quantity(id)}}
+            end)
+            |> Jason.encode!()
+
+          {:ok, %{body: body, status_code: 200}}
+        end)
+      end
+
+      block_numbers = 0..13000
+
+      payload =
+        block_numbers
+        |> Stream.with_index()
+        |> Enum.map(&get_block_by_number_request/1)
+
+      assert_payload_too_large(payload, json_rpc_named_arguments)
+
+      assert {:ok, responses} = EthereumJSONRPC.json_rpc(payload, json_rpc_named_arguments)
+      assert Enum.count(responses) == Enum.count(block_numbers)
+
+      block_number_set = MapSet.new(block_numbers)
+
+      response_block_number_set =
+        Enum.into(responses, MapSet.new(), fn %{result: %{"number" => quantity}} ->
+          EthereumJSONRPC.quantity_to_integer(quantity)
+        end)
+
+      assert MapSet.equal?(response_block_number_set, block_number_set)
+    end
+  end
+
+  defp assert_payload_too_large(payload, json_rpc_named_arguments) do
+    assert Keyword.fetch!(json_rpc_named_arguments, :transport) == EthereumJSONRPC.HTTP
+
+    transport_options = Keyword.fetch!(json_rpc_named_arguments, :transport_options)
+
+    http = Keyword.fetch!(transport_options, :http)
+    url = Keyword.fetch!(transport_options, :url)
+    json = Jason.encode_to_iodata!(payload)
+    http_options = Keyword.fetch!(transport_options, :http_options)
+
+    assert {:ok, %{body: body, status_code: 413}} = http.json_rpc(url, json, http_options)
+    assert body =~ "413 Request Entity Too Large"
+  end
+
+  defp get_block_by_number_request({block_number, id}) do
+    request(%{
+      id: id,
+      method: "eth_getBlockByNumber",
+      params: [EthereumJSONRPC.integer_to_quantity(block_number), true]
+    })
+  end
+end

apps/ethereum_jsonrpc/test/ethereum_jsonrpc/parity_test.exs

@@ -1,61 +1,181 @@
 defmodule EthereumJSONRPC.ParityTest do
   use ExUnit.Case, async: true
+  use EthereumJSONRPC.Case
+
+  import EthereumJSONRPC, only: [integer_to_quantity: 1]
+  import Mox
+
+  setup :verify_on_exit!
+
+  doctest EthereumJSONRPC.Parity
+
+  @moduletag :no_geth
 
   describe "fetch_internal_transactions/1" do
-    @tag :no_geth
+    test "with all valid transaction_params returns {:ok, transactions_params}", %{
-    test "with all valid transaction_params returns {:ok, transactions_params}" do
+      json_rpc_named_arguments: json_rpc_named_arguments
-      assert EthereumJSONRPC.Parity.fetch_internal_transactions([
+    } do
+      from_address_hash = "0xe8ddc5c7a2d2f0d7a9798459c0104fdf5e987aca"
+      gas = 4_533_872
+
+      init =
+        "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"
+
+      value = 0
+      block_number = 1
+      index = 0
+      created_contract_address_hash = "0x1e0eaa06d02f965be2dfe0bc9ff52b2d82133461"
+
+      created_contract_code =
+        "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"
+
+      gas_used = 382_953
+      trace_address = []
+      transaction_hash = "0x0fa6f723216dba694337f9bb37d8870725655bdf2573526a39454685659e39b1"
+      type = "create"
+
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn _json, _options ->
+          {:ok,
+           [
              %{
-                 block_number: 1,
+               id: 0,
-                 hash_data: "0x0fa6f723216dba694337f9bb37d8870725655bdf2573526a39454685659e39b1"
+               result: %{
+                 "trace" => [
+                   %{
+                     "action" => %{
+                       "from" => from_address_hash,
+                       "gas" => integer_to_quantity(gas),
+                       "init" => init,
+                       "value" => integer_to_quantity(value)
+                     },
+                     "blockNumber" => block_number,
+                     "index" => index,
+                     "result" => %{
+                       "address" => created_contract_address_hash,
+                       "code" => created_contract_code,
+                       "gasUsed" => integer_to_quantity(gas_used)
+                     },
+                     "traceAddress" => trace_address,
+                     "transactionHash" => transaction_hash,
+                     "type" => type
+                   }
+                 ]
+               }
              }
-             ]) == {
+           ]}
+        end)
+      end
+
+      assert EthereumJSONRPC.Parity.fetch_internal_transactions(
+               [
+                 %{
+                   block_number: block_number,
+                   hash_data: transaction_hash
+                 }
+               ],
+               json_rpc_named_arguments
+             ) == {
                :ok,
                [
                  %{
                    block_number: 1,
-                   created_contract_address_hash: "0x1e0eaa06d02f965be2dfe0bc9ff52b2d82133461",
+                   created_contract_address_hash: created_contract_address_hash,
-                   created_contract_code:
+                   created_contract_code: created_contract_code,
-                     "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",
+                   from_address_hash: from_address_hash,
-                   from_address_hash: "0xe8ddc5c7a2d2f0d7a9798459c0104fdf5e987aca",
+                   gas: gas,
-                   gas: 4_533_872,
+                   gas_used: gas_used,
-                   gas_used: 382_953,
+                   index: index,
-                   index: 0,
+                   init: init,
-                   init:
+                   trace_address: trace_address,
-                     "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",
+                   transaction_hash: transaction_hash,
-                   trace_address: [],
+                   type: type,
-                   transaction_hash: "0x0fa6f723216dba694337f9bb37d8870725655bdf2573526a39454685659e39b1",
+                   value: value
-                   type: "create",
-                   value: 0
                  }
                ]
              }
     end
 
-    @tag :no_geth
+    test "with all invalid transaction_params returns {:error, reasons}", %{
-    test "with all invalid transaction_params returns {:error, reasons}" do
+      json_rpc_named_arguments: json_rpc_named_arguments
-      assert EthereumJSONRPC.Parity.fetch_internal_transactions([
+    } do
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn _json, _options ->
+          {:ok,
+           [
+             %{
+               id: 0,
+               error: %{
+                 code: -32603,
+                 message: "Internal error occurred: {}, this should not be the case with eth_call, most likely a bug."
+               }
+             }
+           ]}
+        end)
+      end
+
+      assert EthereumJSONRPC.Parity.fetch_internal_transactions(
+               [
                  %{
                    block_number: 1,
                    hash_data: "0x0000000000000000000000000000000000000000000000000000000000000001"
                  }
-             ]) ==
+               ],
+               json_rpc_named_arguments
+             ) ==
                {:error,
                 [
                   %{
+                    code: -32603,
+                    data: %{
                       "blockNumber" => 1,
-                    "code" => -32603,
-                    "data" => "TransactionNotFound",
-                    "message" =>
-                      "Internal error occurred: {}, this should not be the case with eth_call, most likely a bug.",
                       "transactionHash" => "0x0000000000000000000000000000000000000000000000000000000000000001"
+                    },
+                    message:
+                      "Internal error occurred: {}, this should not be the case with eth_call, most likely a bug."
                   }
                 ]}
     end
 
-    @tag :no_geth
+    test "with a mix of valid and invalid transaction_params returns {:error, reasons}", %{
-    test "with a mix of valid and invalid transaction_params returns {:error, reasons}" do
+      json_rpc_named_arguments: json_rpc_named_arguments
-      assert EthereumJSONRPC.Parity.fetch_internal_transactions([
+    } do
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn _json, _options ->
+          {:ok,
+           [
+             %{
+               id: 0,
+               result: %{
+                 "trace" => []
+               }
+             },
+             %{
+               id: 1,
+               result: %{
+                 "trace" => []
+               }
+             },
+             %{
+               id: 2,
+               error: %{
+                 code: -32603,
+                 message: "Internal error occurred: {}, this should not be the case with eth_call, most likely a bug."
+               }
+             },
+             %{
+               id: 3,
+               error: %{
+                 code: -32603,
+                 message: "Internal error occurred: {}, this should not be the case with eth_call, most likely a bug."
+               }
+             }
+           ]}
+        end)
+      end
+
+      assert EthereumJSONRPC.Parity.fetch_internal_transactions(
+               [
                  # start with :ok
                  %{
                    block_number: 1,
@@ -71,42 +191,33 @@ defmodule EthereumJSONRPC.ParityTest do
                    block_number: 1,
                    hash_data: "0x0000000000000000000000000000000000000000000000000000000000000001"
                  },
-               # :error, :ok clause
-               %{
-                 block_number: 35,
-                 hash_data: "0x6b80a90c958fb5791a070929379ed6eb7a33ecdf9f9cafcada2f6803b3f25ec3"
-               },
                  # :error, :error clause
                  %{
                    block_number: 2,
                    hash_data: "0x0000000000000000000000000000000000000000000000000000000000000002"
                  }
-             ]) ==
+               ],
+               json_rpc_named_arguments
+             ) ==
                {:error,
                 [
                   %{
+                    code: -32603,
+                    data: %{
                       "blockNumber" => 1,
-                    "code" => -32603,
-                    "data" => "TransactionNotFound",
-                    "message" =>
-                      "Internal error occurred: {}, this should not be the case with eth_call, most likely a bug.",
                       "transactionHash" => "0x0000000000000000000000000000000000000000000000000000000000000001"
                     },
-                  %{
+                    message:
-                    "blockNumber" => 35,
+                      "Internal error occurred: {}, this should not be the case with eth_call, most likely a bug."
-                    "code" => -32603,
-                    "data" => "TransactionNotFound",
-                    "message" =>
-                      "Internal error occurred: {}, this should not be the case with eth_call, most likely a bug.",
-                    "transactionHash" => "0x6b80a90c958fb5791a070929379ed6eb7a33ecdf9f9cafcada2f6803b3f25ec3"
                   },
                   %{
+                    code: -32603,
+                    data: %{
                       "blockNumber" => 2,
-                    "code" => -32603,
-                    "data" => "TransactionNotFound",
-                    "message" =>
-                      "Internal error occurred: {}, this should not be the case with eth_call, most likely a bug.",
                       "transactionHash" => "0x0000000000000000000000000000000000000000000000000000000000000002"
+                    },
+                    message:
+                      "Internal error occurred: {}, this should not be the case with eth_call, most likely a bug."
                   }
                 ]}
     end

apps/ethereum_jsonrpc/test/ethereum_jsonrpc/receipts_test.exs

@@ -1,80 +1,134 @@
 defmodule EthereumJSONRPC.ReceiptsTest do
   use ExUnit.Case, async: true
+  use EthereumJSONRPC.Case
+
+  import EthereumJSONRPC, only: [integer_to_quantity: 1]
+  import Mox
 
   alias EthereumJSONRPC.Receipts
 
-  setup do
+  setup :verify_on_exit!
-    %{variant: EthereumJSONRPC.config(:variant)}
-  end
 
   doctest Receipts
 
-  # These are integration tests that depend on the sokol chain being used.  sokol can be used with the following config
+  describe "fetch/2" do
-  #
+    test "with receipts and logs", %{json_rpc_named_arguments: json_rpc_named_arguments} do
-  #     config :explorer, EthereumJSONRPC,
+      %{
-  #       trace_url: "https://sokol-trace.poa.network",
+        cumulative_gas_used: cumulative_gas_used,
-  #       url: "https://sokol.poa.network"
+        gas_used: gas_used,
-  #
+        address_hash: address_hash,
-  describe "fetch/1" do
+        block_number: block_number,
-    test "with receipts and logs", %{variant: variant} do
+        data: data,
-      case variant do
+        index: index,
+        first_topic: first_topic,
+        status: status,
+        type: type,
+        transaction_hash: transaction_hash,
+        transaction_index: transaction_index
+      } =
+        case Keyword.fetch!(json_rpc_named_arguments, :variant) do
           EthereumJSONRPC.Geth ->
-          assert {:ok,
             %{
-                    logs: [],
+              cumulative_gas_used: 884_322,
-                    receipts: [
+              address_hash: "0x1e2fbe6be9eb39fc894d38be976111f332172d83",
+              block_number: 3_560_000,
+              data:
+                "0x00000000000000000000000033066f6a8adf2d4f5db193524b6fbae062ec0d110000000000000000000000000000000000000000000000000000000000001030",
+              index: 12,
+              first_topic: "0xf6db2bace4ac8277384553ad9603d045220a91fb2448ab6130d7a6f044f9a8cf",
+              gas_used: 106_025,
+              status: :error,
+              type: nil,
+              transaction_hash: "0xd3efddbbeb6ad8d8bb3f6b8c8fb6165567e9dd868013146bdbeb60953c82822a",
+              transaction_index: 17
+            }
+
+          EthereumJSONRPC.Parity ->
             %{
-                        cumulative_gas_used: 1_238_877,
+              cumulative_gas_used: 50450,
-                        gas_used: 21000,
+              gas_used: 50450,
+              address_hash: "0x8bf38d4764929064f2d4d3a56520a76ab3df415b",
+              block_number: 37,
+              data: "0x000000000000000000000000862d67cb0773ee3f8ce7ea89b328ffea861ab3ef",
+              index: 0,
+              first_topic: "0x600bcf04a13e752d1e3670a5a9f1c21177ca2a93c6f5391d4f1298d098097c22",
               status: :ok,
-                        transaction_hash: "0x360fb62cc817093e5624468735803ea39cad719e5c68ca322bae6ba4f520756f",
+              type: "mined",
-                        transaction_index: 57
+              transaction_hash: "0x53bd884872de3e488692881baeec262e7b95234d3965248c39fe992fffd433e5",
+              transaction_index: 0
             }
-                    ]
+        end
-                  }} =
+
-                   Receipts.fetch([
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        native_status =
+          case status do
+            :ok -> "0x1"
+            :error -> "0x0"
+          end
+
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn _json, _options ->
+          {:ok,
+           [
+             %{
+               id: 0,
+               result: %{
+                 "cumulativeGasUsed" => integer_to_quantity(cumulative_gas_used),
+                 "gasUsed" => integer_to_quantity(gas_used),
+                 "logs" => [
                    %{
-                       gas: 90000,
+                     "address" => address_hash,
-                       hash: "0x360fb62cc817093e5624468735803ea39cad719e5c68ca322bae6ba4f520756f"
+                     "blockNumber" => integer_to_quantity(block_number),
+                     "data" => data,
+                     "logIndex" => integer_to_quantity(index),
+                     "topics" => [first_topic],
+                     "transactionHash" => transaction_hash,
+                     "type" => type
+                   }
+                 ],
+                 "status" => native_status,
+                 "transactionHash" => transaction_hash,
+                 "transactionIndex" => integer_to_quantity(transaction_index)
+               }
              }
-                   ])
+           ]}
+        end)
+      end
 
-        EthereumJSONRPC.Parity ->
       assert {:ok,
               %{
                 logs: [
                   %{
-                        address_hash: "0x8bf38d4764929064f2d4d3a56520a76ab3df415b",
+                    address_hash: ^address_hash,
-                        data: "0x000000000000000000000000862d67cb0773ee3f8ce7ea89b328ffea861ab3ef",
+                    block_number: ^block_number,
-                        first_topic: "0x600bcf04a13e752d1e3670a5a9f1c21177ca2a93c6f5391d4f1298d098097c22",
+                    data: ^data,
+                    first_topic: ^first_topic,
                     fourth_topic: nil,
-                        index: 0,
+                    index: ^index,
                     second_topic: nil,
                     third_topic: nil,
-                        transaction_hash: "0x53bd884872de3e488692881baeec262e7b95234d3965248c39fe992fffd433e5",
+                    transaction_hash: ^transaction_hash
-                        type: "mined"
                   }
+                  | _
                 ],
                 receipts: [
                   %{
-                        cumulative_gas_used: 50450,
+                    cumulative_gas_used: ^cumulative_gas_used,
-                        gas_used: 50450,
+                    gas_used: ^gas_used,
-                        status: :ok,
+                    status: ^status,
-                        transaction_hash: "0x53bd884872de3e488692881baeec262e7b95234d3965248c39fe992fffd433e5",
+                    transaction_hash: ^transaction_hash,
-                        transaction_index: 0
+                    transaction_index: ^transaction_index
                   }
                 ]
               }} =
-                   Receipts.fetch([
+               Receipts.fetch(
+                 [
                    %{
-                       gas: 50451,
+                     gas: 9000,
-                       hash: "0x53bd884872de3e488692881baeec262e7b95234d3965248c39fe992fffd433e5"
+                     hash: transaction_hash
                    }
-                   ])
+                 ],
-
+                 json_rpc_named_arguments
-        _ ->
+               )
-          raise ArgumentError, "Unsupported variant (#{variant})"
-      end
     end
   end
 end

apps/ethereum_jsonrpc/test/support/ethereum_jsonrpc/case.ex

@@ -1,10 +1,79 @@
 defmodule EthereumJSONRPC.Case do
+  @moduledoc """
+  Adds `json_rpc_named_arguments` to context.
+
+  Reads `ETHEREUM_JSONRPC_TRANSPORT` environment variable to determine which module to use `:json_rpc_named_arguments`
+  `:transport`:
+
+  * `EthereumJSONRPC.HTTP` - Allow testing of HTTP-only behavior like status codes
+  * `EthereumJSONRPC.Mox` - mock, transport neutral responses.  The default for local testing.
+
+  When `ETHEREUM_JSONRPC_TRANSPORT` is `EthereumJSONRPC.HTTP`, then reads `ETHEREUM_JSONRPC_HTTP_URL` environment
+  variable to determine `:json_rpc_named_arguments` `:transport_options` `:url`.  Failure to set
+  `ETHEREUM_JSONRPC_HTTP_URL` in this case will raise an `ArgumentError`.
+
+  * `EthereumJSONRPC.HTTP.HTTPoison` - HTTP responses from calls to real chain URLs
+  * `EthereumJSONRPC.HTTP.Mox` - mock HTTP responses, so can be used for HTTP-only behavior like status codes.
+
+  """
+
+  use ExUnit.CaseTemplate
+
   require Logger
 
+  setup do
+    transport = transport()
+
+    transport_options =
+      case transport do
+        EthereumJSONRPC.HTTP ->
+          [
+            http: EthereumJSONRPC.HTTP.Case.http(),
+            url: EthereumJSONRPC.HTTP.Case.url(),
+            http_options: EthereumJSONRPC.HTTP.Case.http_options()
+          ]
+
+        _ ->
+          []
+      end
+
+    %{
+      json_rpc_named_arguments: [
+        transport: transport,
+        transport_options: transport_options,
+        variant: variant()
+      ]
+    }
+  end
+
   def log_bad_gateway(under_test, assertions) do
     case under_test.() do
       {:error, {:bad_gateway, url}} -> Logger.error(fn -> ["Bad Gateway to ", url, ".  Check CloudFlare."] end)
       other -> assertions.(other)
     end
   end
+
+  def module(environment_variable, default) do
+    alias =
+      environment_variable
+      |> System.get_env()
+      |> Kernel.||(default)
+
+    module = Module.concat([alias])
+
+    with {:error, reason} <- Code.ensure_loaded(module) do
+      raise ArgumentError,
+            "Could not load `#{environment_variable}` environment variable module (#{module}) due to #{reason}"
+    end
+
+    module
+  end
+
+  def transport do
+    module("ETHEREUM_JSONRPC_TRANSPORT", "EthereumJSONRPC.Mox")
+  end
+
+  def variant do
+    module("ETHEREUM_JSONRPC_VARIANT", "EthereumJSONRPC.Parity")
+  end
 end

apps/ethereum_jsonrpc/test/support/ethereum_jsonrpc/http/case.ex

@@ -0,0 +1,32 @@
+defmodule EthereumJSONRPC.HTTP.Case do
+  use ExUnit.CaseTemplate
+
+  import EthereumJSONRPC.Case, only: [module: 2]
+
+  setup do
+    %{
+      json_rpc_named_arguments: [
+        transport: EthereumJSONRPC.HTTP,
+        transport_options: [
+          http: http(),
+          url: url(),
+          http_options: http_options()
+        ]
+      ]
+    }
+  end
+
+  def http do
+    module("ETHEREUM_JSONRPC_HTTP", "EthereumJSONRPC.HTTP.Mox")
+  end
+
+  def http_options do
+    [recv_timeout: 60_000, timeout: 60_000, hackney: [pool: :ethereum_jsonrpc]]
+  end
+
+  def url do
+    "ETHEREUM_JSONRPC_HTTP_URL"
+    |> System.get_env()
+    |> Kernel.||("https://example.com")
+  end
+end

apps/ethereum_jsonrpc/test/test_helper.exs

@@ -6,5 +6,9 @@ File.mkdir_p!(junit_folder)
 # Counter `test --no-start`.  `--no-start` is needed for `:indexer` compatibility
 {:ok, _} = Application.ensure_all_started(:ethereum_jsonrpc)
 
+Mox.defmock(EthereumJSONRPC.Mox, for: EthereumJSONRPC.Transport)
+# for when we need to simulate HTTP-specific stuff like 413 Request Entity Too Large
+Mox.defmock(EthereumJSONRPC.HTTP.Mox, for: EthereumJSONRPC.HTTP)
+
 ExUnit.configure(formatters: [JUnitFormatter, ExUnit.CLIFormatter])
 ExUnit.start()

apps/explorer/lib/explorer/chain.ex

@@ -2190,8 +2190,7 @@ defmodule Explorer.Chain do
     |> Repo.insert()
   end
 
-  @spec changes_list(params :: map, [{:for, module} | {:with, :atom}]) ::
+  @spec changes_list(params :: [map], [{:for, module} | {:with, atom}]) :: {:ok, [map]} | {:error, [Changeset.t()]}
-          {:ok, changes :: map} | {:error, [Changeset.t()]}
   defp changes_list(params, options) when is_list(options) do
     ecto_schema_module = Keyword.fetch!(options, :for)
     changeset_function_name = Keyword.get(options, :with, :changeset)
@@ -2395,7 +2394,7 @@ defmodule Explorer.Chain do
     Repo.transaction(multi, timeout: Keyword.get(options, :timeout, @transaction_timeout))
   end
 
-  @spec insert_internal_transactions([map()], [timestamps_option]) ::
+  @spec insert_internal_transactions([map], [timeout_option | timestamps_option]) ::
           {:ok, [%{index: non_neg_integer, transaction_hash: Hash.t()}]}
           | {:error, [Changeset.t()]}
   defp insert_internal_transactions(changes_list, named_arguments)

apps/indexer/config/config.exs

@@ -3,7 +3,9 @@
 use Mix.Config
 
 config :indexer,
-  block_rate: 5_000,
+  debug_logs: !!System.get_env("DEBUG_INDEXER"),
-  debug_logs: !!System.get_env("DEBUG_INDEXER")
+  ecto_repos: [Explorer.Repo]
 
-config :indexer, ecto_repos: [Explorer.Repo]
+# Import environment specific config. This must remain at the bottom
+# of this file so it overrides the configuration defined above.
+import_config "#{Mix.env()}.exs"

apps/indexer/config/dev.exs

@@ -0,0 +1,7 @@
+use Mix.Config
+
+variant = System.get_env("ETHEREUM_JSONRPC_VARIANT") || "parity"
+
+# Import variant specific config. This must remain at the bottom
+# of this file so it overrides the configuration defined above.
+import_config "dev/#{variant}.exs"

apps/indexer/config/dev/geth.exs

@@ -0,0 +1,13 @@
+use Mix.Config
+
+config :indexer,
+  block_rate: 5_000,
+  json_rpc_named_arguments: [
+    transport: EthereumJSONRPC.HTTP,
+    transport_options: [
+      http: EthereumJSONRPC.HTTP.HTTPoison,
+      url: "https://mainnet.infura.io/8lTvJTKmHPCHazkneJsY",
+      http_options: [recv_timeout: 60_000, timeout: 60_000, hackney: [pool: :ethereum_jsonrpc]]
+    ],
+    variant: EthereumJSONRPC.Geth
+  ]

apps/indexer/config/dev/parity.exs

@@ -0,0 +1,17 @@
+use Mix.Config
+
+config :indexer,
+  block_rate: 5_000,
+  json_rpc_named_arguments: [
+    transport: EthereumJSONRPC.HTTP,
+    transport_options: [
+      http: EthereumJSONRPC.HTTP.HTTPoison,
+      url: "https://sokol.poa.network",
+      method_to_url: [
+        eth_getBalance: "https://sokol-trace.poa.network",
+        trace_replayTransaction: "https://sokol-trace.poa.network"
+      ],
+      http_options: [recv_timeout: 60_000, timeout: 60_000, hackney: [pool: :ethereum_jsonrpc]]
+    ],
+    variant: EthereumJSONRPC.Parity
+  ]

apps/indexer/config/prod.exs

@@ -0,0 +1,7 @@
+use Mix.Config
+
+variant = System.get_env("ETHEREUM_JSONRPC_VARIANT") || "parity"
+
+# Import variant specific config. This must remain at the bottom
+# of this file so it overrides the configuration defined above.
+import_config "dev/#{variant}.exs"

apps/indexer/config/prod/geth.exs

@@ -0,0 +1,13 @@
+use Mix.Config
+
+config :indexer,
+  block_rate: 5_000,
+  json_rpc_named_arguments: [
+    transport: EthereumJSONRPC.HTTP,
+    transport_options: [
+      http: EthereumJSONRPC.HTTP.HTTPoison,
+      url: "https://mainnet.infura.io/8lTvJTKmHPCHazkneJsY",
+      http_options: [recv_timeout: 60_000, timeout: 60_000, hackney: [pool: :ethereum_jsonrpc]]
+    ],
+    variant: EthereumJSONRPC.Geth
+  ]

apps/indexer/config/prod/parity.exs

@@ -0,0 +1,17 @@
+use Mix.Config
+
+config :indexer,
+  block_rate: 5_000,
+  json_rpc_named_arguments: [
+    transport: EthereumJSONRPC.HTTP,
+    transport_options: [
+      http: EthereumJSONRPC.HTTP.HTTPoison,
+      url: "https://sokol.poa.network",
+      method_to_url: [
+        eth_getBalance: "https://sokol-trace.poa.network",
+        trace_replayTransaction: "https://sokol-trace.poa.network"
+      ],
+      http_options: [recv_timeout: 60_000, timeout: 60_000, hackney: [pool: :ethereum_jsonrpc]]
+    ],
+    variant: EthereumJSONRPC.Parity
+  ]

apps/indexer/config/test.exs

@@ -0,0 +1 @@
+use Mix.Config

apps/indexer/lib/indexer/address_balance_fetcher.ex

@@ -32,12 +32,24 @@ defmodule Indexer.AddressBalanceFetcher do
 
   @doc false
   def child_spec(provided_opts) do
-    opts = Keyword.merge(@defaults, provided_opts)
+    {state, mergable_opts} = Keyword.pop(provided_opts, :json_rpc_named_arguments)
+
+    unless state do
+      raise ArgumentError,
+            ":json_rpc_named_arguments must be provided to `#{__MODULE__}.child_spec " <>
+              "to allow for json_rpc calls when running."
+    end
+
+    opts =
+      @defaults
+      |> Keyword.merge(mergable_opts)
+      |> Keyword.put(:state, state)
+
     Supervisor.child_spec({BufferedTask, {__MODULE__, opts}}, id: __MODULE__)
   end
 
   @impl BufferedTask
-  def init(initial, reducer) do
+  def init(initial, reducer, _) do
     {:ok, final} =
       Chain.stream_unfetched_addresses(initial, fn address_fields, acc ->
         address_fields
@@ -49,12 +61,12 @@ defmodule Indexer.AddressBalanceFetcher do
   end
 
   @impl BufferedTask
-  def run(params_list, _retries) do
+  def run(params_list, _retries, json_rpc_named_arguments) do
     latest_params_list = latest_params_list(params_list)
 
     Indexer.debug(fn -> "fetching #{length(latest_params_list)} balances" end)
 
-    case EthereumJSONRPC.fetch_balances(latest_params_list) do
+    case EthereumJSONRPC.fetch_balances(latest_params_list, json_rpc_named_arguments) do
       {:ok, addresses_params} ->
         {:ok, _} = Chain.update_balances(addresses_params)
         :ok

apps/indexer/lib/indexer/application.ex

@@ -9,10 +9,12 @@ defmodule Indexer.Application do
 
   @impl Application
   def start(_type, _args) do
+    json_rpc_named_arguments = Application.fetch_env!(:indexer, :json_rpc_named_arguments)
+
     children = [
       {Task.Supervisor, name: Indexer.TaskSupervisor},
-      {AddressBalanceFetcher, name: AddressBalanceFetcher},
+      {AddressBalanceFetcher, name: AddressBalanceFetcher, json_rpc_named_arguments: json_rpc_named_arguments},
-      {PendingTransactionFetcher, name: PendingTransactionFetcher},
+      {PendingTransactionFetcher, name: PendingTransactionFetcher, json_rpc_named_arguments: json_rpc_named_arguments},
       {InternalTransactionFetcher, name: InternalTransactionFetcher},
       {BlockFetcher, []}
     ]

apps/indexer/lib/indexer/block_fetcher.ex

@@ -36,8 +36,7 @@ defmodule Indexer.BlockFetcher do
 
   ## Options
 
-  Default options are pulled from application config under the
+  Default options are pulled from application config under the :indexer` keyspace. The follow options can be overridden:
-  `:explorer, :indexer` keyspace. The follow options can be overridden:
 
     * `:blocks_batch_size` - The number of blocks to request in one call to the JSONRPC.  Defaults to
       `#{@blocks_batch_size}`.  Block requests also include the transactions for those blocks.  *These transactions
@@ -70,6 +69,7 @@ defmodule Indexer.BlockFetcher do
     :timer.send_interval(15_000, self(), :debug_count)
 
     state = %{
+      json_rpc_named_arguments: Keyword.fetch!(opts, :json_rpc_named_arguments),
       genesis_task: nil,
       realtime_task: nil,
       realtime_interval: opts[:block_rate] || @block_rate,
@@ -162,13 +162,13 @@ defmodule Indexer.BlockFetcher do
 
   defp fetch_transaction_receipts(_state, []), do: {:ok, %{logs: [], receipts: []}}
 
-  defp fetch_transaction_receipts(%{} = state, transaction_params) do
+  defp fetch_transaction_receipts(%{json_rpc_named_arguments: json_rpc_named_arguments} = state, transaction_params) do
     debug(fn -> "fetching #{length(transaction_params)} transaction receipts" end)
     stream_opts = [max_concurrency: state.receipts_concurrency, timeout: :infinity]
 
     transaction_params
     |> Enum.chunk_every(state.receipts_batch_size)
-    |> Task.async_stream(&EthereumJSONRPC.fetch_transaction_receipts(&1), stream_opts)
+    |> Task.async_stream(&EthereumJSONRPC.fetch_transaction_receipts(&1, json_rpc_named_arguments), stream_opts)
     |> Enum.reduce_while({:ok, %{logs: [], receipts: []}}, fn
       {:ok, {:ok, %{logs: logs, receipts: receipts}}}, {:ok, %{logs: acc_logs, receipts: acc_receipts}} ->
         {:cont, {:ok, %{logs: acc_logs ++ logs, receipts: acc_receipts ++ receipts}}}
@@ -181,8 +181,8 @@ defmodule Indexer.BlockFetcher do
     end)
   end
 
-  defp genesis_task(%{} = state) do
+  defp genesis_task(%{json_rpc_named_arguments: json_rpc_named_arguments} = state) do
-    {:ok, latest_block_number} = EthereumJSONRPC.fetch_block_number_by_tag("latest")
+    {:ok, latest_block_number} = EthereumJSONRPC.fetch_block_number_by_tag("latest", json_rpc_named_arguments)
     missing_ranges = missing_block_number_ranges(state, latest_block_number..0)
     count = Enum.count(missing_ranges)
 
@@ -294,8 +294,8 @@ defmodule Indexer.BlockFetcher do
     end)
   end
 
-  defp realtime_task(%{} = state) do
+  defp realtime_task(%{json_rpc_named_arguments: json_rpc_named_arguments} = state) do
-    {:ok, latest_block_number} = EthereumJSONRPC.fetch_block_number_by_tag("latest")
+    {:ok, latest_block_number} = EthereumJSONRPC.fetch_block_number_by_tag("latest", json_rpc_named_arguments)
     {:ok, seq} = Sequence.start_link(first: latest_block_number, step: 2)
     stream_import(state, seq, max_concurrency: 1)
   end
@@ -313,8 +313,9 @@ defmodule Indexer.BlockFetcher do
   # Run at state.blocks_concurrency max_concurrency when called by `stream_import/3`
   # Only public for testing
   @doc false
-  def import_range(range, %{} = state, seq) do
+  def import_range(range, %{json_rpc_named_arguments: json_rpc_named_arguments} = state, seq) do
-    with {:blocks, {:ok, next, result}} <- {:blocks, EthereumJSONRPC.fetch_blocks_by_range(range)},
+    with {:blocks, {:ok, next, result}} <-
+           {:blocks, EthereumJSONRPC.fetch_blocks_by_range(range, json_rpc_named_arguments)},
          %{blocks: blocks, transactions: transactions_without_receipts} = result,
          cap_seq(seq, next, range),
          {:receipts, {:ok, receipt_params}} <-

apps/indexer/lib/indexer/buffered_task.ex

@@ -50,6 +50,31 @@ defmodule Indexer.BufferedTask do
 
   require Logger
 
+  alias Indexer.BufferedTask
+
+  @enforce_keys [
+    :pid,
+    :callback_module,
+    :callback_module_state,
+    :task_supervisor,
+    :flush_interval,
+    :max_batch_size,
+    :init_chunk_size
+  ]
+  defstruct pid: nil,
+            init_task: nil,
+            flush_timer: nil,
+            callback_module: nil,
+            callback_module_state: nil,
+            task_supervisor: nil,
+            flush_interval: nil,
+            max_batch_size: nil,
+            max_concurrency: nil,
+            init_chunk_size: nil,
+            current_buffer: [],
+            buffer: :queue.new(),
+            tasks: %{}
+
   @typedoc """
   Entry passed to `t:reducer/2` in `c:init/2` and grouped together into a list as `t:entries/0` passed to `c:run/2`.
   """
@@ -78,21 +103,28 @@ defmodule Indexer.BufferedTask do
   """
   @type reducer :: (entry, accumulator -> accumulator)
 
+  @typedoc """
+  Callback module controlled state.  Can be used to store extra information needed for each `run/2`
+  """
+  @type state :: term()
+
   @doc """
   Populates a task's buffer on boot with an initial set of entries.
 
   For example, the following callback would buffer all unfetched account balances on startup:
 
-      def init(initial, reducer) do
+      def init(initial, reducer, state) do
-        Chain.stream_unfetched_addresses([:hash], initial, fn %{hash: hash}, acc ->
+        final = Chain.stream_unfetched_addresses([:hash], initial, fn %{hash: hash}, acc ->
           reducer.(Hash.to_string(hash), acc)
         end)
+
+        {final, state}
       end
 
   The `init/2` operation may be long-running as it is run in a separate process and allows concurrent calls to
   `Explorer.BufferedTask.buffer/2` for on-demand entries.
   """
-  @callback init(initial, reducer) :: accumulator
+  @callback init(initial, reducer, state) :: accumulator
 
   @doc """
   Invoked as concurrency becomes available with a list of batched entries to be processed.
@@ -116,7 +148,7 @@ defmodule Indexer.BufferedTask do
    * `{:retry, new_entries :: list}` - run should be retried with `new_entries`
 
   """
-  @callback run(entries, retries :: pos_integer) :: :ok | :retry
+  @callback run(entries, retries :: pos_integer, state) :: :ok | :retry | {:retry, new_entries :: list}
 
   @doc """
   Buffers list of entries for future async execution.
@@ -163,6 +195,7 @@ defmodule Indexer.BufferedTask do
              | {:max_concurrency, pos_integer()}
              | {:name, GenServer.name()}
              | {:task_supervisor, GenServer.name()}
+             | {:state, state}
            ]}
         ) :: {:ok, pid()} | {:error, {:already_started, pid()}}
   def start_link({module, base_opts}) do
@@ -175,19 +208,15 @@ defmodule Indexer.BufferedTask do
   def init({callback_module, opts}) do
     send(self(), :initial_stream)
 
-    state = %{
+    state = %BufferedTask{
       pid: self(),
-      init_task: nil,
-      flush_timer: nil,
       callback_module: callback_module,
+      callback_module_state: Keyword.fetch!(opts, :state),
       task_supervisor: Keyword.fetch!(opts, :task_supervisor),
       flush_interval: Keyword.fetch!(opts, :flush_interval),
       max_batch_size: Keyword.fetch!(opts, :max_batch_size),
       max_concurrency: Keyword.fetch!(opts, :max_concurrency),
-      init_chunk_size: Keyword.fetch!(opts, :init_chunk_size),
+      init_chunk_size: Keyword.fetch!(opts, :init_chunk_size)
-      current_buffer: [],
-      buffer: :queue.new(),
-      tasks: %{}
     }
 
     {:ok, state}
@@ -217,7 +246,7 @@ defmodule Indexer.BufferedTask do
     {:noreply, state}
   end
 
-  def handle_info({:DOWN, ref, :process, _pid, :normal}, %{init_task: ref} = state) do
+  def handle_info({:DOWN, ref, :process, _pid, :normal}, %BufferedTask{init_task: ref} = state) do
     {:noreply, %{state | init_task: :complete}}
   end
 
@@ -245,7 +274,7 @@ defmodule Indexer.BufferedTask do
   end
 
   defp drop_task(state, ref) do
-    spawn_next_batch(%{state | tasks: Map.delete(state.tasks, ref)})
+    spawn_next_batch(%BufferedTask{state | tasks: Map.delete(state.tasks, ref)})
   end
 
   defp drop_task_and_retry(state, ref, new_batch \\ nil) do
@@ -262,7 +291,7 @@ defmodule Indexer.BufferedTask do
     %{state | current_buffer: [entries | state.current_buffer]}
   end
 
-  defp queue_in_state(%{} = state, batch, retries) do
+  defp queue_in_state(%BufferedTask{} = state, batch, retries) do
     %{state | buffer: queue_in_queue(state.buffer, batch, retries)}
   end
 
@@ -270,11 +299,14 @@ defmodule Indexer.BufferedTask do
     :queue.in({batch, retries}, queue)
   end
 
-  defp do_initial_stream(%{init_chunk_size: init_chunk_size} = state) do
+  defp do_initial_stream(
+         %BufferedTask{callback_module_state: callback_module_state, init_chunk_size: init_chunk_size} = state
+       ) do
     task =
       Task.Supervisor.async(state.task_supervisor, fn ->
         {0, []}
-        |> state.callback_module.init(fn
+        |> state.callback_module.init(
+          fn
             entry, {len, acc} when len + 1 >= init_chunk_size ->
               [entry | acc]
               |> chunk_into_queue(state)
@@ -284,11 +316,13 @@ defmodule Indexer.BufferedTask do
 
             entry, {len, acc} ->
               {len + 1, [entry | acc]}
-        end)
+          end,
+          callback_module_state
+        )
         |> catchup_remaining(state)
       end)
 
-    schedule_next_buffer_flush(%{state | init_task: task.ref})
+    schedule_next_buffer_flush(%BufferedTask{state | init_task: task.ref})
   end
 
   defp catchup_remaining({0, []}, _state), do: :ok
@@ -330,7 +364,7 @@ defmodule Indexer.BufferedTask do
 
       task =
         Task.Supervisor.async_nolink(state.task_supervisor, fn ->
-          {:performed, state.callback_module.run(batch, retries)}
+          {:performed, state.callback_module.run(batch, retries, state.callback_module_state)}
         end)
 
       %{state | tasks: Map.put(state.tasks, task.ref, {batch, retries}), buffer: new_queue}
@@ -339,11 +373,11 @@ defmodule Indexer.BufferedTask do
     end
   end
 
-  defp flush(%{current_buffer: []} = state) do
+  defp flush(%BufferedTask{current_buffer: []} = state) do
     state |> spawn_next_batch() |> schedule_next_buffer_flush()
   end
 
-  defp flush(%{current_buffer: current} = state) do
+  defp flush(%BufferedTask{current_buffer: current} = state) do
     current
     |> List.flatten()
     |> Enum.chunk_every(state.max_batch_size)

apps/indexer/lib/indexer/internal_transaction_fetcher.ex

@@ -48,12 +48,24 @@ defmodule Indexer.InternalTransactionFetcher do
 
   @doc false
   def child_spec(provided_opts) do
-    opts = Keyword.merge(@defaults, provided_opts)
+    {state, mergable_opts} = Keyword.pop(provided_opts, :json_rpc_named_arguments)
+
+    unless state do
+      raise ArgumentError,
+            ":json_rpc_named_arguments must be provided to `#{__MODULE__}.child_spec " <>
+              "to allow for json_rpc calls when running."
+    end
+
+    opts =
+      @defaults
+      |> Keyword.merge(mergable_opts)
+      |> Keyword.put(:state, state)
+
     Supervisor.child_spec({BufferedTask, {__MODULE__, opts}}, id: __MODULE__)
   end
 
   @impl BufferedTask
-  def init(initial, reducer) do
+  def init(initial, reducer, _) do
     {:ok, final} =
       Chain.stream_transactions_with_unfetched_internal_transactions(
         [:block_number, :hash],
@@ -73,12 +85,12 @@ defmodule Indexer.InternalTransactionFetcher do
   end
 
   @impl BufferedTask
-  def run(transactions_params, _retries) do
+  def run(transactions_params, _retries, json_rpc_named_arguments) do
     unique_transactions_params = unique_transactions_params(transactions_params)
 
     Indexer.debug(fn -> "fetching internal transactions for #{length(unique_transactions_params)} transactions" end)
 
-    case EthereumJSONRPC.fetch_internal_transactions(unique_transactions_params) do
+    case EthereumJSONRPC.fetch_internal_transactions(unique_transactions_params, json_rpc_named_arguments) do
       {:ok, internal_transactions_params} ->
         addresses_params = AddressExtraction.extract_addresses(%{internal_transactions: internal_transactions_params})
 

apps/indexer/lib/indexer/pending_transaction_fetcher.ex

@@ -9,7 +9,7 @@ defmodule Indexer.PendingTransactionFetcher do
 
   require Logger
 
-  import EthereumJSONRPC, only: [fetch_pending_transactions: 0]
+  import EthereumJSONRPC, only: [fetch_pending_transactions: 1]
 
   alias Explorer.Chain
   alias Indexer.{AddressExtraction, PendingTransactionFetcher}
@@ -18,6 +18,7 @@ defmodule Indexer.PendingTransactionFetcher do
   @default_interval 1_000
 
   defstruct interval: @default_interval,
+            json_rpc_named_arguments: [],
             task_ref: nil,
             task_pid: nil
 
@@ -35,6 +36,8 @@ defmodule Indexer.PendingTransactionFetcher do
     * `:pending_transaction_interval` - the millisecond time between checking for pending transactions.  Defaults to
       `#{@default_interval}` milliseconds.
     * `:spawn_opt` - if present, its value is passed as options to the underlying process as in `Process.spawn/4`
+    * `:json_rpc_named_arguments` - `t:EthereumJSONRPC.json_rpc_named_arguments/0` passed to
+      `EthereumJSONRPC.json_rpc/2`.
     * `:timeout` - if present, the server is allowed to spend the given number of milliseconds initializing or it will
       be terminated and the start function will return `{:error, :timeout}`
 
@@ -51,7 +54,10 @@ defmodule Indexer.PendingTransactionFetcher do
       |> Keyword.merge(opts)
 
     state =
-      %PendingTransactionFetcher{interval: opts[:pending_transaction_interval] || @default_interval}
+      %PendingTransactionFetcher{
+        json_rpc_named_arguments: Keyword.fetch!(opts, :json_rpc_named_arguments),
+        interval: opts[:pending_transaction_interval] || @default_interval
+      }
       |> schedule_fetch()
 
     {:ok, state}
@@ -84,8 +90,8 @@ defmodule Indexer.PendingTransactionFetcher do
     state
   end
 
-  defp task(%PendingTransactionFetcher{} = _state) do
+  defp task(%PendingTransactionFetcher{json_rpc_named_arguments: json_rpc_named_arguments} = _state) do
-    case fetch_pending_transactions() do
+    case fetch_pending_transactions(json_rpc_named_arguments) do
       {:ok, transactions_params} ->
         addresses_params = AddressExtraction.extract_addresses(%{transactions: transactions_params}, pending: true)
 

apps/indexer/mix.exs

@@ -39,7 +39,9 @@ defmodule Indexer.MixProject do
       # JSONRPC access to Parity for `Explorer.Indexer`
       {:ethereum_jsonrpc, in_umbrella: true},
       # Importing to database
-      {:explorer, in_umbrella: true}
+      {:explorer, in_umbrella: true},
+      # Mocking `EthereumJSONRPC.Transport`, so we avoid hitting real chains for local testing
+      {:mox, "~> 0.3.2", only: [:test]}
     ]
   end
 

apps/indexer/test/indexer/address_balance_fetcher_test.exs

@@ -1,19 +1,35 @@
 defmodule Indexer.AddressBalanceFetcherTest do
   # MUST be `async: false` so that {:shared, pid} is set for connection to allow AddressBalanceFetcher's self-send to have
   # connection allowed immediately.
-  use Explorer.DataCase, async: false
+  use EthereumJSONRPC.Case, async: false
+  use Explorer.DataCase
+
+  import EthereumJSONRPC, only: [integer_to_quantity: 1]
+  import Mox
 
   alias Explorer.Chain.{Address, Hash, Wei}
   alias Indexer.{AddressBalanceFetcher, AddressBalanceFetcherCase}
 
+  @moduletag :capture_log
+
+  # MUST use global mode because we aren't guaranteed to get `start_supervised`'s pid back fast enough to `allow` it to
+  # use expectations and stubs from test's pid.
+  setup :set_mox_global
+
+  setup :verify_on_exit!
+
   setup do
     start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
 
-    %{variant: EthereumJSONRPC.config(:variant)}
+    :ok
   end
 
   describe "init/1" do
-    test "fetches unfetched Block miner balance", %{variant: variant} do
+    test "fetches unfetched Block miner balance", %{
+      json_rpc_named_arguments: json_rpc_named_arguments
+    } do
+      variant = Keyword.fetch!(json_rpc_named_arguments, :variant)
+
       %{block_number: block_number, fetched_balance: fetched_balance, miner_hash_data: miner_hash_data} =
         case variant do
           EthereumJSONRPC.Geth ->
@@ -30,10 +46,20 @@ defmodule Indexer.AddressBalanceFetcherTest do
               miner_hash_data: "0xe8ddc5c7a2d2f0d7a9798459c0104fdf5e987aca"
             }
 
-          _ ->
+          variant ->
             raise ArgumentError, "Unsupported variant (#{variant})"
         end
 
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        block_quantity = integer_to_quantity(block_number)
+
+        EthereumJSONRPC.Mox
+        |> expect(:json_rpc, fn [%{id: id, method: "eth_getBalance", params: [^miner_hash_data, ^block_quantity]}],
+                                _options ->
+          {:ok, [%{id: id, result: integer_to_quantity(fetched_balance)}]}
+        end)
+      end
+
       {:ok, miner_hash} = Hash.Address.cast(miner_hash_data)
       miner = insert(:address, hash: miner_hash)
       block = insert(:block, miner: miner, number: block_number)
@@ -41,7 +67,7 @@ defmodule Indexer.AddressBalanceFetcherTest do
       assert miner.fetched_balance == nil
       assert miner.fetched_balance_block_number == nil
 
-      AddressBalanceFetcherCase.start_supervised!()
+      AddressBalanceFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments)
 
       fetched_address =
         wait(fn ->
@@ -54,7 +80,11 @@ defmodule Indexer.AddressBalanceFetcherTest do
       assert fetched_address.fetched_balance_block_number == block.number
     end
 
-    test "fetches unfetched addresses when less than max batch size", %{variant: variant} do
+    test "fetches unfetched addresses when less than max batch size", %{
+      json_rpc_named_arguments: json_rpc_named_arguments
+    } do
+      variant = Keyword.fetch!(json_rpc_named_arguments, :variant)
+
       %{block_number: block_number, fetched_balance: fetched_balance, miner_hash_data: miner_hash_data} =
         case variant do
           EthereumJSONRPC.Geth ->
@@ -71,15 +101,25 @@ defmodule Indexer.AddressBalanceFetcherTest do
               miner_hash_data: "0xe8ddc5c7a2d2f0d7a9798459c0104fdf5e987aca"
             }
 
-          _ ->
+          variant ->
             raise ArgumentError, "Unsupported variant (#{variant})"
         end
 
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        block_quantity = integer_to_quantity(block_number)
+
+        EthereumJSONRPC.Mox
+        |> expect(:json_rpc, fn [%{id: id, method: "eth_getBalance", params: [^miner_hash_data, ^block_quantity]}],
+                                _options ->
+          {:ok, [%{id: id, result: integer_to_quantity(fetched_balance)}]}
+        end)
+      end
+
       {:ok, miner_hash} = Hash.Address.cast(miner_hash_data)
       miner = insert(:address, hash: miner_hash)
       block = insert(:block, miner: miner, number: block_number)
 
-      AddressBalanceFetcherCase.start_supervised!(max_batch_size: 2)
+      AddressBalanceFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments, max_batch_size: 2)
 
       fetched_address =
         wait(fn ->
@@ -94,8 +134,8 @@ defmodule Indexer.AddressBalanceFetcherTest do
   end
 
   describe "async_fetch_balances/1" do
-    test "fetches balances for address_hashes", %{variant: variant} do
+    test "fetches balances for address_hashes", %{json_rpc_named_arguments: json_rpc_named_arguments} do
-      AddressBalanceFetcherCase.start_supervised!()
+      variant = Keyword.fetch!(json_rpc_named_arguments, :variant)
 
       %{block_number: block_number, fetched_balance: fetched_balance, hash: hash} =
         case variant do
@@ -120,10 +160,23 @@ defmodule Indexer.AddressBalanceFetcherTest do
               }
             }
 
-          _ ->
+          variant ->
             raise ArgumentError, "Unsupported variant (#{variant})"
         end
 
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        block_quantity = integer_to_quantity(block_number)
+        hash_data = to_string(hash)
+
+        EthereumJSONRPC.Mox
+        |> expect(:json_rpc, fn [%{id: id, method: "eth_getBalance", params: [^hash_data, ^block_quantity]}],
+                                _options ->
+          {:ok, [%{id: id, result: integer_to_quantity(fetched_balance)}]}
+        end)
+      end
+
+      AddressBalanceFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments)
+
       assert :ok = AddressBalanceFetcher.async_fetch_balances([%{block_number: block_number, hash: hash}])
 
       address =
@@ -137,10 +190,11 @@ defmodule Indexer.AddressBalanceFetcherTest do
   end
 
   describe "run/2" do
-    @tag capture_log: true
+    test "duplicate address hashes the max block_quantity", %{
-    test "duplicate address hashes the max block_quantity", %{variant: variant} do
+      json_rpc_named_arguments: json_rpc_named_arguments
+    } do
       %{fetched_balance: fetched_balance, hash_data: hash_data} =
-        case variant do
+        case Keyword.fetch!(json_rpc_named_arguments, :variant) do
           EthereumJSONRPC.Geth ->
             %{
               fetched_balance: 5_000_000_000_000_000_000,
@@ -153,13 +207,21 @@ defmodule Indexer.AddressBalanceFetcherTest do
               hash_data: "0xe8ddc5c7a2d2f0d7a9798459c0104fdf5e987aca"
             }
 
-          _ ->
+          variant ->
             raise ArgumentError, "Unsupported variant (#{variant})"
         end
 
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        EthereumJSONRPC.Mox
+        |> expect(:json_rpc, fn [%{id: id, method: "eth_getBalance", params: [^hash_data, "0x2"]}], _options ->
+          {:ok, [%{id: id, result: integer_to_quantity(fetched_balance)}]}
+        end)
+      end
+
       case AddressBalanceFetcher.run(
              [%{block_quantity: "0x1", hash_data: hash_data}, %{block_quantity: "0x2", hash_data: hash_data}],
-             0
+             0,
+             json_rpc_named_arguments
            ) do
         :ok ->
           fetched_address = Repo.one!(from(address in Address, where: address.hash == ^hash_data))
@@ -177,12 +239,20 @@ defmodule Indexer.AddressBalanceFetcherTest do
       end
     end
 
-    test "duplicate address hashes only retry max block_quantity" do
+    test "duplicate address hashes only retry max block_quantity", %{json_rpc_named_arguments: json_rpc_named_arguments} do
       hash_data = "0x000000000000000000000000000000000"
 
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        EthereumJSONRPC.Mox
+        |> expect(:json_rpc, fn [%{id: id, method: "eth_getBalance", params: [^hash_data, "0x2"]}], _options ->
+          {:ok, [%{id: id, error: %{code: 404, message: "Not Found"}}]}
+        end)
+      end
+
       assert AddressBalanceFetcher.run(
                [%{block_quantity: "0x1", hash_data: hash_data}, %{block_quantity: "0x2", hash_data: hash_data}],
-               0
+               0,
+               json_rpc_named_arguments
              ) ==
                {:retry,
                 [

apps/indexer/test/indexer/block_fetcher_test.exs

@@ -1,8 +1,11 @@
 defmodule Indexer.BlockFetcherTest do
   # `async: false` due to use of named GenServer
-  use Explorer.DataCase, async: false
+  use EthereumJSONRPC.Case, async: false
+  use Explorer.DataCase
 
   import ExUnit.CaptureLog
+  import Mox
+  import EthereumJSONRPC, only: [integer_to_quantity: 1]
   import EthereumJSONRPC.Case
 
   alias Explorer.Chain.{Address, Block, Log, Transaction, Wei}
@@ -17,7 +20,13 @@ defmodule Indexer.BlockFetcherTest do
     Sequence
   }
 
-  @tag capture_log: true
+  @moduletag capture_log: true
+
+  # MUST use global mode because we aren't guaranteed to get `start_supervised`'s pid back fast enough to `allow` it to
+  # use expectations and stubs from test's pid.
+  setup :set_mox_global
+
+  setup :verify_on_exit!
 
   # First block with all schemas to import
   # 37 is determined using the following query:
@@ -37,13 +46,173 @@ defmodule Indexer.BlockFetcherTest do
   #  ON blocks.hash = transactions.block_hash) as blocks
   @first_full_block_number 37
 
-  setup do
+  describe "start_link/1" do
-    %{variant: EthereumJSONRPC.config(:variant)}
+    test "starts fetching blocks from latest and goes down", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        case Keyword.fetch!(json_rpc_named_arguments, :variant) do
+          EthereumJSONRPC.Parity ->
+            block_number = 3_416_888
+            block_quantity = integer_to_quantity(block_number)
+
+            EthereumJSONRPC.Mox
+            |> stub(:json_rpc, fn
+              # latest block number to seed starting block number for genesis and realtime tasks
+              %{method: "eth_getBlockByNumber", params: ["latest", false]}, _options ->
+                {:ok,
+                 %{
+                   "author" => "0xe2ac1c6843a33f81ae4935e5ef1277a392990381",
+                   "difficulty" => "0xfffffffffffffffffffffffffffffffe",
+                   "extraData" => "0xd583010a068650617269747986312e32362e32826c69",
+                   "gasLimit" => "0x7a1200",
+                   "gasUsed" => "0x0",
+                   "hash" => "0x627baabf5a17c0cfc547b6903ac5e19eaa91f30d9141be1034e3768f6adbc94e",
+                   "logsBloom" =>
+                     "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+                   "miner" => "0xe2ac1c6843a33f81ae4935e5ef1277a392990381",
+                   "number" => block_quantity,
+                   "parentHash" => "0x006edcaa1e6fde822908783bc4ef1ad3675532d542fce53537557391cfe34c3c",
+                   "receiptsRoot" => "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+                   "sealFields" => [
+                     "0x841240b30d",
+                     "0xb84158bc4fa5891934bc94c5dca0301867ce4f35925ef46ea187496162668210bba61b4cda09d7e0dca2f1dd041fad498ced6697aeef72656927f52c55b630f2591c01"
+                   ],
+                   "sha3Uncles" => "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
+                   "signature" =>
+                     "58bc4fa5891934bc94c5dca0301867ce4f35925ef46ea187496162668210bba61b4cda09d7e0dca2f1dd041fad498ced6697aeef72656927f52c55b630f2591c01",
+                   "size" => "0x243",
+                   "stateRoot" => "0x9a8111062667f7b162851a1cbbe8aece5ff12e761b3dcee93b787fcc12548cf7",
+                   "step" => "306230029",
+                   "timestamp" => "0x5b437f41",
+                   "totalDifficulty" => "0x342337ffffffffffffffffffffffffed8d29bb",
+                   "transactions" => [],
+                   "transactionsRoot" => "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+                   "uncles" => []
+                 }}
+
+              [%{method: "eth_getBlockByNumber", params: [_, true]} | _] = requests, _options ->
+                {:ok,
+                 Enum.map(requests, fn %{id: id, params: [block_quantity, true]} ->
+                   %{
+                     id: id,
+                     jsonrpc: "2.0",
+                     result: %{
+                       "author" => "0xe2ac1c6843a33f81ae4935e5ef1277a392990381",
+                       "difficulty" => "0xfffffffffffffffffffffffffffffffe",
+                       "extraData" => "0xd583010a068650617269747986312e32362e32826c69",
+                       "gasLimit" => "0x7a1200",
+                       "gasUsed" => "0x0",
+                       "hash" =>
+                         Explorer.Factory.block_hash()
+                         |> to_string(),
+                       "logsBloom" =>
+                         "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+                       "miner" => "0xe2ac1c6843a33f81ae4935e5ef1277a392990381",
+                       "number" => block_quantity,
+                       "parentHash" =>
+                         Explorer.Factory.block_hash()
+                         |> to_string(),
+                       "receiptsRoot" => "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+                       "sealFields" => [
+                         "0x841240b30d",
+                         "0xb84158bc4fa5891934bc94c5dca0301867ce4f35925ef46ea187496162668210bba61b4cda09d7e0dca2f1dd041fad498ced6697aeef72656927f52c55b630f2591c01"
+                       ],
+                       "sha3Uncles" => "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
+                       "signature" =>
+                         "58bc4fa5891934bc94c5dca0301867ce4f35925ef46ea187496162668210bba61b4cda09d7e0dca2f1dd041fad498ced6697aeef72656927f52c55b630f2591c01",
+                       "size" => "0x243",
+                       "stateRoot" => "0x9a8111062667f7b162851a1cbbe8aece5ff12e761b3dcee93b787fcc12548cf7",
+                       "step" => "306230029",
+                       "timestamp" => "0x5b437f41",
+                       "totalDifficulty" => "0x342337ffffffffffffffffffffffffed8d29bb",
+                       "transactions" => [],
+                       "transactionsRoot" => "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+                       "uncles" => []
+                     }
+                   }
+                 end)}
+
+              [%{method: "eth_getBalance"} | _] = requests, _options ->
+                {:ok, Enum.map(requests, fn %{id: id} -> %{id: id, jsonrpc: "2.0", result: "0x0"} end)}
+            end)
+
+          EthereumJSONRPC.Geth ->
+            block_number = 5_950_901
+            block_quantity = integer_to_quantity(block_number)
+
+            EthereumJSONRPC.Mox
+            |> stub(:json_rpc, fn
+              %{method: "eth_getBlockByNumber", params: ["latest", false]}, _options ->
+                {:ok,
+                 %{
+                   "difficulty" => "0xc2550dc5bfc5d",
+                   "extraData" => "0x65746865726d696e652d657538",
+                   "gasLimit" => "0x7a121d",
+                   "gasUsed" => "0x6cc04b",
+                   "hash" => "0x71f484056fec687fd469989426c94c469ff08a28eae9a1865359d64557bb99f6",
+                   "logsBloom" =>
+                     "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",
+                   "miner" => "0xea674fdde714fd979de3edf0f56aa9716b898ec8",
+                   "mixHash" => "0x555275cd0ab4c3b2fe3936843ee25bb67da05ef7dcf17216bc0e382d21d139a0",
+                   "nonce" => "0xa49e42a024600113",
+                   "number" => block_quantity,
+                   "parentHash" => "0xb4357733c59cc6f785542d072a205f4e195f7198f544ea5e01c1b90ef0f914a5",
+                   "receiptsRoot" => "0x17baf8de366fecc1be494bff245be6357ac60a5fe786099dba89983778c8421e",
+                   "sha3Uncles" => "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
+                   "size" => "0x6c7b",
+                   "stateRoot" => "0x79345c692a0bf363e95c37750336c534309b3f3fe8b59712ac1527118070f488",
+                   "timestamp" => "0x5b475377",
+                   "totalDifficulty" => "0x120258e22c69502fc88",
+                   "transactions" => ["0xa4b58d1d1473f4891d9ff91f624dba73611bf1f6e9a60d3ca2dcfc75d2ab185c"],
+                   "transactionsRoot" => "0x5972b7988f667d7e86679322641117e503ea2c1bc5a27822a8a8120fe53f2c8b",
+                   "uncles" => []
+                 }}
+
+              [%{method: "eth_getBlockByNumber", params: [_, true]} | _] = requests, _options ->
+                {:ok,
+                 Enum.map(requests, fn %{id: id, params: [block_quantity, true]} ->
+                   %{
+                     id: id,
+                     jsonrpc: "2.0",
+                     result: %{
+                       "difficulty" => "0xc22479024e55f",
+                       "extraData" => "0x73656f3130",
+                       "gasLimit" => "0x7a121d",
+                       "gasUsed" => "0x7a0527",
+                       "hash" =>
+                         Explorer.Factory.block_hash()
+                         |> to_string(),
+                       "logsBloom" =>
+                         "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",
+                       "miner" => "0xb2930b35844a230f00e51431acae96fe543a0347",
+                       "mixHash" => "0x5e07a58028d2cee7ddbefe245e6d7b5232d997b66cc906b18ad9ad51535ced24",
+                       "nonce" => "0x3d88ebe8031aadf6",
+                       "number" => block_quantity,
+                       "parentHash" =>
+                         Explorer.Factory.block_hash()
+                         |> to_string(),
+                       "receiptsRoot" => "0x5294a8b56be40c0c198aa443664e801bb926d49878f96151849f3ddd0cb5e76d",
+                       "sha3Uncles" => "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
+                       "size" => "0x4796",
+                       "stateRoot" => "0x3755d4b5c9ae3cd58d7a856a46fbe8fb69f0ba93d81e831cd68feb8b61bc3009",
+                       "timestamp" => "0x5b475393",
+                       "totalDifficulty" => "0x120259a450e2527e1e7",
+                       "transactions" => [],
+                       "transactionsRoot" => "0xa71969ed649cd1f21846ab7b4029e79662941cc34cd473aa4590e666920ad2f4",
+                       "uncles" => []
+                     }
+                   }
+                 end)}
+
+              [%{method: "eth_getBalance"} | _] = requests, _options ->
+                {:ok, Enum.map(requests, fn %{id: id} -> %{id: id, jsonrpc: "2.0", result: "0x0"} end)}
+            end)
+
+          variant_name ->
+            raise ArgumentError, "Unsupported variant name (#{variant_name})"
+        end
       end
 
-  describe "start_link/1" do
+      {:ok, latest_block_number} = EthereumJSONRPC.fetch_block_number_by_tag("latest", json_rpc_named_arguments)
-    test "starts fetching blocks from latest and goes down" do
-      {:ok, latest_block_number} = EthereumJSONRPC.fetch_block_number_by_tag("latest")
 
       default_blocks_batch_size = BlockFetcher.default_blocks_batch_size()
 
@@ -52,9 +221,9 @@ defmodule Indexer.BlockFetcherTest do
       assert Repo.aggregate(Block, :count, :hash) == 0
 
       start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
-      AddressBalanceFetcherCase.start_supervised!()
+      AddressBalanceFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments)
-      InternalTransactionFetcherCase.start_supervised!()
+      InternalTransactionFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments)
-      start_supervised!(BlockFetcher)
+      start_supervised!({BlockFetcher, json_rpc_named_arguments: json_rpc_named_arguments})
 
       wait_for_results(fn ->
         Repo.one!(from(block in Block, where: block.number == ^latest_block_number))
@@ -93,10 +262,10 @@ defmodule Indexer.BlockFetcherTest do
 
     @tag :capture_log
     @heading "persisted counts"
-    test "without debug_logs", %{state: state} do
+    test "without debug_logs", %{json_rpc_named_arguments: json_rpc_named_arguments, state: state} do
       start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
-      AddressBalanceFetcherCase.start_supervised!()
+      AddressBalanceFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments)
-      InternalTransactionFetcherCase.start_supervised!()
+      InternalTransactionFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments)
 
       wait_for_tasks(InternalTransactionFetcher)
       wait_for_tasks(AddressBalanceFetcher)
@@ -108,10 +277,10 @@ defmodule Indexer.BlockFetcherTest do
     end
 
     @tag :capture_log
-    test "with debug_logs", %{state: state} do
+    test "with debug_logs", %{json_rpc_named_arguments: json_rpc_named_arguments, state: state} do
       start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
-      AddressBalanceFetcherCase.start_supervised!()
+      AddressBalanceFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments)
-      InternalTransactionFetcherCase.start_supervised!()
+      InternalTransactionFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments)
 
       wait_for_tasks(InternalTransactionFetcher)
       wait_for_tasks(AddressBalanceFetcher)
@@ -133,20 +302,135 @@ defmodule Indexer.BlockFetcherTest do
   describe "import_range/3" do
     setup :state
 
-    setup do
+    setup %{json_rpc_named_arguments: json_rpc_named_arguments} do
       start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
-      AddressBalanceFetcherCase.start_supervised!()
+      AddressBalanceFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments)
-      InternalTransactionFetcherCase.start_supervised!()
+      InternalTransactionFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments)
-      {:ok, state} = BlockFetcher.init([])
+      {:ok, state} = BlockFetcher.init(json_rpc_named_arguments: json_rpc_named_arguments)
 
       %{state: state}
     end
 
-    test "with single element range that is valid imports one block", %{state: state, variant: variant} do
+    test "with single element range that is valid imports one block", %{
+      json_rpc_named_arguments: json_rpc_named_arguments,
+      state: state
+    } do
+      block_number = 0
+
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        block_quantity = integer_to_quantity(block_number)
+        miner_hash = "0x0000000000000000000000000000000000000000"
+
+        case Keyword.fetch!(json_rpc_named_arguments, :variant) do
+          EthereumJSONRPC.Parity ->
+            EthereumJSONRPC.Mox
+            |> expect(:json_rpc, fn [%{id: id, method: "eth_getBlockByNumber", params: [^block_quantity, true]}],
+                                    _options ->
+              {:ok,
+               [
+                 %{
+                   id: id,
+                   jsonrpc: "2.0",
+                   result: %{
+                     "author" => "0x0000000000000000000000000000000000000000",
+                     "difficulty" => "0x20000",
+                     "extraData" => "0x",
+                     "gasLimit" => "0x663be0",
+                     "gasUsed" => "0x0",
+                     "hash" => "0x5b28c1bfd3a15230c9a46b399cd0f9a6920d432e85381cc6a140b06e8410112f",
+                     "logsBloom" =>
+                       "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+                     "miner" => miner_hash,
+                     "number" => block_quantity,
+                     "parentHash" => "0x0000000000000000000000000000000000000000000000000000000000000000",
+                     "receiptsRoot" => "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+                     "sealFields" => [
+                       "0x80",
+                       "0xb8410000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
+                     ],
+                     "sha3Uncles" => "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
+                     "signature" =>
+                       "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+                     "size" => "0x215",
+                     "stateRoot" => "0xfad4af258fd11939fae0c6c6eec9d340b1caac0b0196fd9a1bc3f489c5bf00b3",
+                     "step" => "0",
+                     "timestamp" => "0x0",
+                     "totalDifficulty" => "0x20000",
+                     "transactions" => [],
+                     "transactionsRoot" => "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+                     "uncles" => []
+                   }
+                 }
+               ]}
+            end)
+            |> expect(:json_rpc, fn [
+                                      %{
+                                        id: id,
+                                        jsonrpc: "2.0",
+                                        method: "eth_getBalance",
+                                        params: [^miner_hash, ^block_quantity]
+                                      }
+                                    ],
+                                    _options ->
+              {:ok, [%{id: id, jsonrpc: "2.0", result: "0x0"}]}
+            end)
+
+          EthereumJSONRPC.Geth ->
+            EthereumJSONRPC.Mox
+            |> expect(:json_rpc, fn [%{id: id, method: "eth_getBlockByNumber", params: [^block_quantity, true]}],
+                                    _options ->
+              {:ok,
+               [
+                 %{
+                   id: id,
+                   jsonrpc: "2.0",
+                   result: %{
+                     "difficulty" => "0x400000000",
+                     "extraData" => "0x11bbe8db4e347b4e8c937c1c8370e4b5ed33adb3db69cbdb7a38e1e50b1b82fa",
+                     "gasLimit" => "0x1388",
+                     "gasUsed" => "0x0",
+                     "hash" => "0xd4e56740f876aef8c010b86a40d5f56745a118d0906a34e69aec8c0db1cb8fa3",
+                     "logsBloom" =>
+                       "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+                     "miner" => miner_hash,
+                     "mixHash" => "0x0000000000000000000000000000000000000000000000000000000000000000",
+                     "nonce" => "0x0000000000000042",
+                     "number" => block_quantity,
+                     "parentHash" => "0x0000000000000000000000000000000000000000000000000000000000000000",
+                     "receiptsRoot" => "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+                     "sha3Uncles" => "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
+                     "size" => "0x21c",
+                     "stateRoot" => "0xd7f8974fb5ac78d9ac099b9ad5018bedc2ce0a72dad1827a1709da30580f0544",
+                     "timestamp" => "0x0",
+                     "totalDifficulty" => "0x400000000",
+                     "transactions" => [],
+                     "transactionsRoot" => "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+                     "uncles" => []
+                   }
+                 }
+               ]}
+            end)
+            |> expect(:json_rpc, fn [
+                                      %{
+                                        id: id,
+                                        jsonrpc: "2.0",
+                                        method: "eth_getBalance",
+                                        params: [^miner_hash, ^block_quantity]
+                                      }
+                                    ],
+                                    _options ->
+              {:ok, [%{id: id, jsonrpc: "2.0", result: "0x0"}]}
+            end)
+
+          variant_name ->
+            raise ArgumentError, "Unsupported variant name (#{variant_name})"
+        end
+      end
+
       {:ok, sequence} = Sequence.start_link(first: 0, step: 1)
 
       %{address_hash: address_hash, block_hash: block_hash} =
-        case variant do
+        case Keyword.fetch!(json_rpc_named_arguments, :variant) do
           EthereumJSONRPC.Geth ->
             %{
               address_hash: %Explorer.Chain.Hash{
@@ -175,12 +459,12 @@ defmodule Indexer.BlockFetcherTest do
               }
             }
 
-          _ ->
+          variant ->
-            raise ArgumenrError, "Unsupported variant (#{variant})"
+            raise ArgumentError, "Unsupported variant (#{variant})"
         end
 
       log_bad_gateway(
-        fn -> BlockFetcher.import_range(0..0, state, sequence) end,
+        fn -> BlockFetcher.import_range(block_number..block_number, state, sequence) end,
         fn result ->
           assert {:ok,
                   %{
@@ -204,10 +488,185 @@ defmodule Indexer.BlockFetcherTest do
       )
     end
 
-    test "can import range with all synchronous imported schemas", %{state: state, variant: variant} do
+    # We can't currently index the whole Ethereum Mainnet, so we don't know what is the first full block.
+    #   Implement when a full block is found for Ethereum Mainnet and remove :no_geth tag
+    @tag :no_geth
+    test "can import range with all synchronous imported schemas", %{
+      json_rpc_named_arguments: json_rpc_named_arguments,
+      state: state
+    } do
+      block_number = @first_full_block_number
+
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        case Keyword.fetch!(json_rpc_named_arguments, :variant) do
+          EthereumJSONRPC.Parity ->
+            block_quantity = integer_to_quantity(block_number)
+            from_address_hash = "0xe8ddc5c7a2d2f0d7a9798459c0104fdf5e987aca"
+            to_address_hash = "0x8bf38d4764929064f2d4d3a56520a76ab3df415b"
+            transaction_hash = "0x53bd884872de3e488692881baeec262e7b95234d3965248c39fe992fffd433e5"
+
+            EthereumJSONRPC.Mox
+            |> expect(:json_rpc, fn json, _options ->
+              assert [%{id: id, method: "eth_getBlockByNumber", params: [^block_quantity, true]}] = json
+
+              {:ok,
+               [
+                 %{
+                   id: id,
+                   jsonrpc: "2.0",
+                   result: %{
+                     "author" => "0xe8ddc5c7a2d2f0d7a9798459c0104fdf5e987aca",
+                     "difficulty" => "0xfffffffffffffffffffffffffffffffe",
+                     "extraData" => "0xd5830108048650617269747986312e32322e31826c69",
+                     "gasLimit" => "0x69fe20",
+                     "gasUsed" => "0xc512",
+                     "hash" => "0xf6b4b8c88df3ebd252ec476328334dc026cf66606a84fb769b3d3cbccc8471bd",
+                     "logsBloom" =>
+                       "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000200000000000000000000020000000000000000200000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+                     "miner" => "0xe8ddc5c7a2d2f0d7a9798459c0104fdf5e987aca",
+                     "number" => "0x25",
+                     "parentHash" => "0xc37bbad7057945d1bf128c1ff009fb1ad632110bf6a000aac025a80f7766b66e",
+                     "receiptsRoot" => "0xd300311aab7dcc98c05ac3f1893629b2c9082c189a0a0c76f4f63e292ac419d5",
+                     "sealFields" => [
+                       "0x84120a71de",
+                       "0xb841fcdb570511ec61edda93849bb7c6b3232af60feb2ea74e4035f0143ab66dfdd00f67eb3eda1adddbb6b572db1e0abd39ce00f9b3ccacb9f47973279ff306fe5401"
+                     ],
+                     "sha3Uncles" => "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
+                     "signature" =>
+                       "fcdb570511ec61edda93849bb7c6b3232af60feb2ea74e4035f0143ab66dfdd00f67eb3eda1adddbb6b572db1e0abd39ce00f9b3ccacb9f47973279ff306fe5401",
+                     "size" => "0x2cf",
+                     "stateRoot" => "0x2cd84079b0d0c267ed387e3895fd1c1dc21ff82717beb1132adac64276886e19",
+                     "step" => "302674398",
+                     "timestamp" => "0x5a343956",
+                     "totalDifficulty" => "0x24ffffffffffffffffffffffffedf78dfd",
+                     "transactions" => [
+                       %{
+                         "blockHash" => "0xf6b4b8c88df3ebd252ec476328334dc026cf66606a84fb769b3d3cbccc8471bd",
+                         "blockNumber" => "0x25",
+                         "chainId" => "0x4d",
+                         "condition" => nil,
+                         "creates" => nil,
+                         "from" => from_address_hash,
+                         "gas" => "0x47b760",
+                         "gasPrice" => "0x174876e800",
+                         "hash" => transaction_hash,
+                         "input" => "0x10855269000000000000000000000000862d67cb0773ee3f8ce7ea89b328ffea861ab3ef",
+                         "nonce" => "0x4",
+                         "publicKey" =>
+                           "0xe5d196ad4ceada719d9e592f7166d0c75700f6eab2e3c3de34ba751ea786527cb3f6eb96ad9fdfdb9989ff572df50f1c42ef800af9c5207a38b929aff969b5c9",
+                         "r" => "0xa7f8f45cce375bb7af8750416e1b03e0473f93c256da2285d1134fc97a700e01",
+                         "raw" =>
+                           "0xf88a0485174876e8008347b760948bf38d4764929064f2d4d3a56520a76ab3df415b80a410855269000000000000000000000000862d67cb0773ee3f8ce7ea89b328ffea861ab3ef81bea0a7f8f45cce375bb7af8750416e1b03e0473f93c256da2285d1134fc97a700e01a01f87a076f13824f4be8963e3dffd7300dae64d5f23c9a062af0c6ead347c135f",
+                         "s" => "0x1f87a076f13824f4be8963e3dffd7300dae64d5f23c9a062af0c6ead347c135f",
+                         "standardV" => "0x1",
+                         "to" => to_address_hash,
+                         "transactionIndex" => "0x0",
+                         "v" => "0xbe",
+                         "value" => "0x0"
+                       }
+                     ],
+                     "transactionsRoot" => "0x68e314a05495f390f9cd0c36267159522e5450d2adf254a74567b452e767bf34",
+                     "uncles" => []
+                   }
+                 }
+               ]}
+            end)
+            |> expect(:json_rpc, fn json, _options ->
+              assert [
+                       %{
+                         id: id,
+                         method: "eth_getTransactionReceipt",
+                         params: ["0x53bd884872de3e488692881baeec262e7b95234d3965248c39fe992fffd433e5"]
+                       }
+                     ] = json
+
+              {:ok,
+               [
+                 %{
+                   id: id,
+                   jsonrpc: "2.0",
+                   result: %{
+                     "blockHash" => "0xf6b4b8c88df3ebd252ec476328334dc026cf66606a84fb769b3d3cbccc8471bd",
+                     "blockNumber" => "0x25",
+                     "contractAddress" => nil,
+                     "cumulativeGasUsed" => "0xc512",
+                     "gasUsed" => "0xc512",
+                     "logs" => [
+                       %{
+                         "address" => "0x8bf38d4764929064f2d4d3a56520a76ab3df415b",
+                         "blockHash" => "0xf6b4b8c88df3ebd252ec476328334dc026cf66606a84fb769b3d3cbccc8471bd",
+                         "blockNumber" => "0x25",
+                         "data" => "0x000000000000000000000000862d67cb0773ee3f8ce7ea89b328ffea861ab3ef",
+                         "logIndex" => "0x0",
+                         "topics" => ["0x600bcf04a13e752d1e3670a5a9f1c21177ca2a93c6f5391d4f1298d098097c22"],
+                         "transactionHash" => "0x53bd884872de3e488692881baeec262e7b95234d3965248c39fe992fffd433e5",
+                         "transactionIndex" => "0x0",
+                         "transactionLogIndex" => "0x0",
+                         "type" => "mined"
+                       }
+                     ],
+                     "logsBloom" =>
+                       "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000200000000000000000000020000000000000000200000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+                     "root" => nil,
+                     "status" => "0x1",
+                     "transactionHash" => "0x53bd884872de3e488692881baeec262e7b95234d3965248c39fe992fffd433e5",
+                     "transactionIndex" => "0x0"
+                   }
+                 }
+               ]}
+            end)
+            # async requests need to be grouped in one expect because the order is non-deterministic while multiple expect
+            # calls on the same name/arity are used in order
+            |> expect(:json_rpc, 5, fn json, _options ->
+              [request] = json
+
+              case request do
+                %{id: id, method: "eth_getBalance", params: [^to_address_hash, ^block_quantity]} ->
+                  {:ok, [%{id: id, jsonrpc: "2.0", result: "0x1"}]}
+
+                %{id: id, method: "eth_getBalance", params: [^from_address_hash, ^block_quantity]} ->
+                  {:ok, [%{id: id, jsonrpc: "2.0", result: "0xd0d4a965ab52d8cd740000"}]}
+
+                %{id: id, method: "trace_replayTransaction", params: [^transaction_hash, ["trace"]]} ->
+                  {:ok,
+                   [
+                     %{
+                       id: id,
+                       jsonrpc: "2.0",
+                       result: %{
+                         "output" => "0x",
+                         "stateDiff" => nil,
+                         "trace" => [
+                           %{
+                             "action" => %{
+                               "callType" => "call",
+                               "from" => from_address_hash,
+                               "gas" => "0x475ec8",
+                               "input" => "0x10855269000000000000000000000000862d67cb0773ee3f8ce7ea89b328ffea861ab3ef",
+                               "to" => to_address_hash,
+                               "value" => "0x0"
+                             },
+                             "result" => %{"gasUsed" => "0x6c7a", "output" => "0x"},
+                             "subtraces" => 0,
+                             "traceAddress" => [],
+                             "type" => "call"
+                           }
+                         ],
+                         "vmTrace" => nil
+                       }
+                     }
+                   ]}
+              end
+            end)
+
+          variant ->
+            raise ArgumentError, "Unsupported variant (#{variant})"
+        end
+      end
+
       {:ok, sequence} = Sequence.start_link(first: 0, step: 1)
 
-      case variant do
+      case Keyword.fetch!(json_rpc_named_arguments, :variant) do
         EthereumJSONRPC.Geth ->
           block_number = 48230
 
@@ -344,7 +803,7 @@ defmodule Indexer.BlockFetcherTest do
                             57, 101, 36, 140, 57, 254, 153, 47, 255, 212, 51, 229>>
                       }
                     ]
-                  }} = BlockFetcher.import_range(@first_full_block_number..@first_full_block_number, state, sequence)
+                  }} = BlockFetcher.import_range(block_number..block_number, state, sequence)
 
           wait_for_tasks(InternalTransactionFetcher)
           wait_for_tasks(AddressBalanceFetcher)
@@ -357,14 +816,14 @@ defmodule Indexer.BlockFetcherTest do
           first_address = Repo.get!(Address, first_address_hash)
 
           assert first_address.fetched_balance == %Wei{value: Decimal.new(1)}
-          assert first_address.fetched_balance_block_number == @first_full_block_number
+          assert first_address.fetched_balance_block_number == block_number
 
           second_address = Repo.get!(Address, second_address_hash)
 
           assert second_address.fetched_balance == %Wei{value: Decimal.new(252_460_837_000_000_000_000_000_000)}
-          assert second_address.fetched_balance_block_number == @first_full_block_number
+          assert second_address.fetched_balance_block_number == block_number
 
-        _ ->
+        variant ->
           raise ArgumentError, "Unsupport variant (#{variant})"
       end
     end
@@ -395,8 +854,8 @@ defmodule Indexer.BlockFetcherTest do
     return
   end
 
-  defp state(_) do
+  defp state(%{json_rpc_named_arguments: json_rpc_named_arguments}) do
-    {:ok, state} = BlockFetcher.init([])
+    {:ok, state} = BlockFetcher.init(json_rpc_named_arguments: json_rpc_named_arguments)
 
     %{state: state}
   end

apps/indexer/test/indexer/buffered_task_test.exs

@@ -11,6 +11,7 @@ defmodule Indexer.BufferedTaskTest do
     start_supervised(
       {BufferedTask,
        {callback_module,
+        state: nil,
         task_supervisor: BufferedTaskSup,
         flush_interval: 50,
         max_batch_size: @max_batch_size,
@@ -24,11 +25,11 @@ defmodule Indexer.BufferedTaskTest do
 
     def initial_collection, do: for(i <- 1..11, do: "#{i}")
 
-    def init(initial, reducer) do
+    def init(initial, reducer, _state) do
       Enum.reduce(initial_collection(), initial, fn item, acc -> reducer.(item, acc) end)
     end
 
-    def run(batch, 0) do
+    def run(batch, 0, _state) do
       send(__MODULE__, {:run, batch})
       :ok
     end
@@ -37,11 +38,11 @@ defmodule Indexer.BufferedTaskTest do
   defmodule EmptyTask do
     @behaviour BufferedTask
 
-    def init(initial, _reducer) do
+    def init(initial, _reducer, _state) do
       initial
     end
 
-    def run(batch, 0) do
+    def run(batch, 0, _state) do
       send(__MODULE__, {:run, batch})
       :ok
     end
@@ -50,31 +51,31 @@ defmodule Indexer.BufferedTaskTest do
   defmodule RetryableTask do
     @behaviour BufferedTask
 
-    def init(initial, _reducer) do
+    def init(initial, _reducer, _state) do
       initial
     end
 
-    def run([:boom], 0) do
+    def run([:boom], 0, _state) do
       send(__MODULE__, {:run, {0, :boom}})
       raise "boom"
     end
 
-    def run([:boom], 1) do
+    def run([:boom], 1, _state) do
       send(__MODULE__, {:run, {1, :boom}})
       :ok
     end
 
-    def run([{:sleep, time}], _) do
+    def run([{:sleep, time}], _, _state) do
       :timer.sleep(time)
       :ok
     end
 
-    def run(batch, retries) when retries < 2 do
+    def run(batch, retries, _state) when retries < 2 do
       send(__MODULE__, {:run, {retries, batch}})
       :retry
     end
 
-    def run(batch, retries) do
+    def run(batch, retries, _state) do
       send(__MODULE__, {:final_run, {retries, batch}})
       :ok
     end

apps/indexer/test/indexer/internal_transaction_fetcher_test.exs

@@ -1,39 +1,94 @@
 defmodule Indexer.InternalTransactionFetcherTest do
-  use Explorer.DataCase, async: false
+  use EthereumJSONRPC.Case, async: false
+  use Explorer.DataCase
 
   import ExUnit.CaptureLog
+  import Mox
 
-  alias Indexer.{AddressBalanceFetcherCase, InternalTransactionFetcher}
+  alias Indexer.{AddressBalanceFetcherCase, InternalTransactionFetcher, PendingTransactionFetcher}
 
-  @moduletag :capture_log
+  # MUST use global mode because we aren't guaranteed to get PendingTransactionFetcher's pid back fast enough to `allow`
+  # it to use expectations and stubs from test's pid.
+  setup :set_mox_global
+
+  setup :verify_on_exit!
+
+  @moduletag [capture_log: true, no_geth: true]
+
+  test "does not try to fetch pending transactions from Indexer.PendingTransactionFetcher", %{
+    json_rpc_named_arguments: json_rpc_named_arguments
+  } do
+    if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+      case Keyword.fetch!(json_rpc_named_arguments, :variant) do
+        EthereumJSONRPC.Parity ->
+          EthereumJSONRPC.Mox
+          |> expect(:json_rpc, fn _json, _options ->
+            {:ok,
+             [
+               %{
+                 "blockHash" => nil,
+                 "blockNumber" => nil,
+                 "chainId" => "0x4d",
+                 "condition" => nil,
+                 "creates" => "0xffc87239eb0267bc3ca2cd51d12fbf278e02ccb4",
+                 "from" => "0xe8ddc5c7a2d2f0d7a9798459c0104fdf5e987aca",
+                 "gas" => "0x47b760",
+                 "gasPrice" => "0x174876e800",
+                 "hash" => "0x3a3eb134e6792ce9403ea4188e5e79693de9e4c94e499db132be086400da79e6",
+                 "input" =>
+                   "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",
+                 "nonce" => "0x0",
+                 "publicKey" =>
+                   "0xe5d196ad4ceada719d9e592f7166d0c75700f6eab2e3c3de34ba751ea786527cb3f6eb96ad9fdfdb9989ff572df50f1c42ef800af9c5207a38b929aff969b5c9",
+                 "r" => "0xad3733df250c87556335ffe46c23e34dbaffde93097ef92f52c88632a40f0c75",
+                 "raw" =>
+                   "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",
+                 "s" => "0x72caddc0371451a58de2ca6ab64e0f586ccdb9465ff54e1c82564940e89291e3",
+                 "standardV" => "0x0",
+                 "to" => nil,
+                 "transactionIndex" => nil,
+                 "v" => "0xbd",
+                 "value" => "0x0"
+               }
+             ]}
+          end)
+          |> stub(:json_rpc, fn _json, _options ->
+            {:ok, []}
+          end)
+
+        variant_name ->
+          raise ArgumentError, "Unsupported variant name (#{variant_name})"
+      end
+    end
 
-  @tag :no_geth
-  test "does not try to fetch pending transactions from Indexer.PendingTransactionFetcher" do
     start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
-    AddressBalanceFetcherCase.start_supervised!()
+    AddressBalanceFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments)
-    start_supervised!(Indexer.PendingTransactionFetcher)
+    start_supervised!({PendingTransactionFetcher, json_rpc_named_arguments: json_rpc_named_arguments})
 
     wait_for_results(fn ->
       Repo.one!(from(transaction in Explorer.Chain.Transaction, where: is_nil(transaction.block_hash), limit: 1))
     end)
 
-    :transaction
+    hash_strings =
-    |> insert(hash: "0x3a3eb134e6792ce9403ea4188e5e79693de9e4c94e499db132be086400da79e6")
+      InternalTransactionFetcher.init([], fn hash_string, acc -> [hash_string | acc] end, json_rpc_named_arguments)
-    |> with_block()
-
-    hash_strings = InternalTransactionFetcher.init([], fn hash_string, acc -> [hash_string | acc] end)
 
-    assert :ok = InternalTransactionFetcher.run(hash_strings, 0)
+    assert :ok = InternalTransactionFetcher.run(hash_strings, 0, json_rpc_named_arguments)
   end
 
   describe "init/2" do
-    test "does not buffer pending transactions" do
+    test "does not buffer pending transactions", %{json_rpc_named_arguments: json_rpc_named_arguments} do
       insert(:transaction)
 
-      assert InternalTransactionFetcher.init([], fn hash_string, acc -> [hash_string | acc] end) == []
+      assert InternalTransactionFetcher.init(
+               [],
+               fn hash_string, acc -> [hash_string | acc] end,
+               json_rpc_named_arguments
+             ) == []
     end
 
-    test "buffers collated transactions with unfetched internal transactions" do
+    test "buffers collated transactions with unfetched internal transactions", %{
+      json_rpc_named_arguments: json_rpc_named_arguments
+    } do
       block = insert(:block)
 
       collated_unfetched_transaction =
@@ -41,24 +96,40 @@ defmodule Indexer.InternalTransactionFetcherTest do
         |> insert()
         |> with_block(block)
 
-      assert InternalTransactionFetcher.init([], fn hash_string, acc -> [hash_string | acc] end) == [
+      assert InternalTransactionFetcher.init(
+               [],
+               fn hash_string, acc -> [hash_string | acc] end,
+               json_rpc_named_arguments
+             ) == [
                %{block_number: block.number, hash_data: to_string(collated_unfetched_transaction.hash)}
              ]
     end
 
-    test "does not buffer collated transactions with fetched internal transactions" do
+    test "does not buffer collated transactions with fetched internal transactions", %{
+      json_rpc_named_arguments: json_rpc_named_arguments
+    } do
       :transaction
       |> insert()
       |> with_block(internal_transactions_indexed_at: DateTime.utc_now())
 
-      assert InternalTransactionFetcher.init([], fn hash_string, acc -> [hash_string | acc] end) == []
+      assert InternalTransactionFetcher.init(
+               [],
+               fn hash_string, acc -> [hash_string | acc] end,
+               json_rpc_named_arguments
+             ) == []
     end
   end
 
   describe "run/2" do
-    test "duplicate transaction hashes are logged" do
+    test "duplicate transaction hashes are logged", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn _json, _options ->
+          {:ok, [%{id: 0, result: %{"trace" => []}}]}
+        end)
+      end
+
       start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
-      AddressBalanceFetcherCase.start_supervised!()
+      AddressBalanceFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments)
 
       insert(:transaction, hash: "0x03cd5899a63b6f6222afda8705d059fd5a7d126bcabe962fb654d9736e6bcafa")
 
@@ -69,7 +140,8 @@ defmodule Indexer.InternalTransactionFetcherTest do
               %{block_number: 1, hash_data: "0x03cd5899a63b6f6222afda8705d059fd5a7d126bcabe962fb654d9736e6bcafa"},
               %{block_number: 1, hash_data: "0x03cd5899a63b6f6222afda8705d059fd5a7d126bcabe962fb654d9736e6bcafa"}
             ],
-            0
+            0,
+            json_rpc_named_arguments
           )
         end)
 
@@ -81,10 +153,15 @@ defmodule Indexer.InternalTransactionFetcherTest do
                """
     end
 
-    @tag :no_geth
+    test "duplicate transaction hashes only retry uniques", %{json_rpc_named_arguments: json_rpc_named_arguments} do
-    test "duplicate transaction hashes only retry uniques" do
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn _json, _options ->
+          {:ok, [%{id: 0, error: %{code: -32602, message: "Invalid params"}}]}
+        end)
+      end
+
       start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
-      AddressBalanceFetcherCase.start_supervised!()
+      AddressBalanceFetcherCase.start_supervised!(json_rpc_named_arguments: json_rpc_named_arguments)
 
       # not a real transaction hash, so that it fails
       insert(:transaction, hash: "0x0000000000000000000000000000000000000000000000000000000000000001")
@@ -94,7 +171,8 @@ defmodule Indexer.InternalTransactionFetcherTest do
                  %{block_number: 1, hash_data: "0x0000000000000000000000000000000000000000000000000000000000000001"},
                  %{block_number: 1, hash_data: "0x0000000000000000000000000000000000000000000000000000000000000001"}
                ],
-               0
+               0,
+               json_rpc_named_arguments
              ) ==
                {:retry,
                 [%{block_number: 1, hash_data: "0x0000000000000000000000000000000000000000000000000000000000000001"}]}

apps/indexer/test/indexer/pending_transaction_fetcher_test.exs

@@ -1,18 +1,65 @@
 defmodule Indexer.PendingTransactionFetcherTest do
   # `async: false` due to use of named GenServer
-  use Explorer.DataCase, async: false
+  use EthereumJSONRPC.Case, async: false
+  use Explorer.DataCase
+
+  import Mox
 
-  describe "start_link/1" do
-    @tag :no_geth
-    # this test may fail if Sokol so low volume that the pending transactions are empty for too long
-    test "starts fetching pending transactions" do
   alias Explorer.Chain.Transaction
   alias Indexer.PendingTransactionFetcher
 
+  # MUST use global mode because we aren't guaranteed to get PendingTransactionFetcher's pid back fast enough to `allow`
+  # it to use expectations and stubs from test's pid.
+  setup :set_mox_global
+
+  setup :verify_on_exit!
+
+  @moduletag [capture_log: true, no_geth: true]
+
+  describe "start_link/1" do
+    # this test may fail if Sokol so low volume that the pending transactions are empty for too long
+    test "starts fetching pending transactions", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+      if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
+        EthereumJSONRPC.Mox
+        |> expect(:json_rpc, fn _json, _options ->
+          {:ok,
+           [
+             %{
+               "blockHash" => nil,
+               "blockNumber" => nil,
+               "chainId" => "0x4d",
+               "condition" => nil,
+               "creates" => "0xffc87239eb0267bc3ca2cd51d12fbf278e02ccb4",
+               "from" => "0xe8ddc5c7a2d2f0d7a9798459c0104fdf5e987aca",
+               "gas" => "0x47b760",
+               "gasPrice" => "0x174876e800",
+               "hash" => "0x3a3eb134e6792ce9403ea4188e5e79693de9e4c94e499db132be086400da79e6",
+               "input" =>
+                 "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",
+               "nonce" => "0x0",
+               "publicKey" =>
+                 "0xe5d196ad4ceada719d9e592f7166d0c75700f6eab2e3c3de34ba751ea786527cb3f6eb96ad9fdfdb9989ff572df50f1c42ef800af9c5207a38b929aff969b5c9",
+               "r" => "0xad3733df250c87556335ffe46c23e34dbaffde93097ef92f52c88632a40f0c75",
+               "raw" =>
+                 "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",
+               "s" => "0x72caddc0371451a58de2ca6ab64e0f586ccdb9465ff54e1c82564940e89291e3",
+               "standardV" => "0x0",
+               "to" => nil,
+               "transactionIndex" => nil,
+               "v" => "0xbd",
+               "value" => "0x0"
+             }
+           ]}
+        end)
+        |> stub(:json_rpc, fn _json, _options ->
+          {:ok, []}
+        end)
+      end
+
       assert Repo.aggregate(Transaction, :count, :hash) == 0
 
       start_supervised!({Task.Supervisor, name: Indexer.TaskSupervisor})
-      start_supervised!(PendingTransactionFetcher)
+      start_supervised!({PendingTransactionFetcher, json_rpc_named_arguments: json_rpc_named_arguments})
 
       wait_for_results(fn ->
         Repo.one!(from(transaction in Transaction, where: is_nil(transaction.block_hash), limit: 1))

apps/indexer/test/test_helper.exs

@@ -14,6 +14,8 @@ end
 # no declared in :applications since it is test-only
 {:ok, _} = Application.ensure_all_started(:ex_machina)
 
+Mox.defmock(EthereumJSONRPC.Mox, for: EthereumJSONRPC.Transport)
+
 ExUnit.configure(formatters: [JUnitFormatter, ExUnit.CLIFormatter])
 ExUnit.start()