Merge branch 'master' into release_build

.credo.exs

@@ -75,7 +75,7 @@
         # Priority values are: `low, normal, high, higher`
         #
         {Credo.Check.Design.AliasUsage,
-         excluded_namespaces: ~w(Import Socket Task),
+         excluded_namespaces: ~w(Block Blocks Import Socket Task),
          excluded_lastnames: ~w(Address DateTime Exporter Fetcher Full Instrumenter Monitor Name Number Repo Time Unit),
          priority: :low},
 

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc.ex

@@ -25,16 +25,14 @@ defmodule EthereumJSONRPC do
   documentation for `EthereumJSONRPC.RequestCoordinator`.
   """
 
-  alias Explorer.Chain.Block
-
   alias EthereumJSONRPC.{
+    Block,
     Blocks,
+    FetchedBalances,
     Receipts,
     RequestCoordinator,
     Subscription,
-    Transactions,
     Transport,
-    Uncles,
     Variant
   }
 
@@ -88,11 +86,6 @@ defmodule EthereumJSONRPC do
           {:transport, Transport.t()} | {:transport_options, Transport.options()} | {:variant, Variant.t()}
         ]
 
-  @typedoc """
-  If there are more blocks.
-  """
-  @type next :: :end_of_chain | :more
-
   @typedoc """
   8 byte [KECCAK-256](https://en.wikipedia.org/wiki/SHA-3) hash of the proof-of-work.
   """
@@ -190,25 +183,16 @@ defmodule EthereumJSONRPC do
   @spec fetch_balances(
           [%{required(:block_quantity) => quantity, required(:hash_data) => data()}],
           json_rpc_named_arguments
-        ) ::
-          {:ok,
-           [
-             %{
-               required(:address_hash) => quantity,
-               required(:block_number) => Block.block_number(),
-               required(:value) => non_neg_integer()
-             }
-           ]}
-          | {:error, reason :: term}
+        ) :: {:ok, FetchedBalances.t()} | {:error, reason :: term}
   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()
+           |> FetchedBalances.requests()
            |> json_rpc(json_rpc_named_arguments) do
-      get_balance_responses_to_balances_params(responses, id_to_params)
+      {:ok, FetchedBalances.from_responses(responses, id_to_params)}
     end
   end
 
@@ -224,43 +208,21 @@ defmodule EthereumJSONRPC do
 
   Transaction data is included for each block.
   """
+  @spec fetch_blocks_by_hash([hash()], json_rpc_named_arguments) :: {:ok, Blocks.t()} | {:error, reason :: term}
   def fetch_blocks_by_hash(block_hashes, json_rpc_named_arguments) do
-    id_to_params =
-      block_hashes
-      |> Enum.map(fn block_hash -> %{hash: block_hash} end)
-      |> id_to_params()
-
-    id_to_params
-    |> get_block_by_hash_requests()
-    |> json_rpc(json_rpc_named_arguments)
-    |> handle_get_blocks(id_to_params)
-    |> case do
-      {:ok, _next, results} -> {:ok, results}
-      {:error, reason} -> {:error, reason}
-    end
+    block_hashes
+    |> Enum.map(fn block_hash -> %{hash: block_hash} end)
+    |> fetch_blocks_by_params(&Block.ByHash.request/1, json_rpc_named_arguments)
   end
 
   @doc """
   Fetches blocks by block number range.
   """
-  @spec fetch_blocks_by_range(Range.t(), json_rpc_named_arguments) ::
-          {:ok, next,
-           %{
-             blocks: Blocks.params(),
-             block_second_degree_relations: Uncles.params(),
-             transactions: Transactions.params()
-           }}
-          | {:error, [reason :: term, ...]}
+  @spec fetch_blocks_by_range(Range.t(), json_rpc_named_arguments) :: {:ok, Blocks.t()} | {:error, reason :: term}
   def fetch_blocks_by_range(_first.._last = range, json_rpc_named_arguments) do
-    id_to_params =
-      range
-      |> Enum.map(fn number -> %{number: number} end)
-      |> id_to_params()
-
-    id_to_params
-    |> get_block_by_number_requests()
-    |> json_rpc(json_rpc_named_arguments)
-    |> handle_get_blocks(id_to_params)
+    range
+    |> Enum.map(fn number -> %{number: number} end)
+    |> fetch_blocks_by_params(&Block.ByNumber.request/1, json_rpc_named_arguments)
   end
 
   @doc """
@@ -276,10 +238,10 @@ defmodule EthereumJSONRPC do
   @spec fetch_block_number_by_tag(tag(), json_rpc_named_arguments) ::
           {:ok, non_neg_integer()} | {:error, reason :: :invalid_tag | :not_found | 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()
+    %{id: 0, tag: tag}
+    |> Block.ByTag.request()
     |> json_rpc(json_rpc_named_arguments)
-    |> handle_get_block_by_tag()
+    |> Block.ByTag.number_from_result()
   end
 
   @doc """
@@ -312,6 +274,7 @@ defmodule EthereumJSONRPC do
   @doc """
   Assigns an id to each set of params in `params_list` for batch request-response correlation
   """
+  @spec id_to_params([params]) :: %{id => params} when id: non_neg_integer(), params: map()
   def id_to_params(params_list) do
     params_list
     |> Stream.with_index()
@@ -420,162 +383,15 @@ defmodule EthereumJSONRPC do
     |> Timex.from_unix()
   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})
-    end)
-  end
-
-  defp get_balance_request(%{id: id, block_quantity: block_quantity, hash_data: hash_data}) do
-    request(%{id: id, method: "eth_getBalance", params: [hash_data, block_quantity]})
-  end
-
-  defp get_balance_responses_to_balances_params(responses, id_to_params)
-       when is_list(responses) and is_map(id_to_params) do
-    {status, reversed} =
-      responses
-      |> Enum.map(&get_balance_responses_to_balance_params(&1, id_to_params))
-      |> Enum.reduce(
-        {:ok, []},
-        fn
-          {:ok, address_params}, {:ok, address_params_list} ->
-            {:ok, [address_params | address_params_list]}
-
-          {:ok, _}, {:error, _} = acc_error ->
-            acc_error
-
-          {:error, reason}, {:ok, _} ->
-            {:error, [reason]}
-
-          {:error, reason}, {:error, acc_reason} ->
-            {:error, [reason | acc_reason]}
-        end
-      )
-
-    {status, Enum.reverse(reversed)}
-  end
-
-  defp get_balance_responses_to_balance_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)
-
-    {:ok,
-     %{
-       value: quantity_to_integer(fetched_balance_quantity),
-       block_number: quantity_to_integer(block_quantity),
-       address_hash: hash_data
-     }}
-  end
-
-  defp get_balance_responses_to_balance_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.put(error, :data, %{"blockNumber" => block_quantity, "hash" => hash_data})
-
-    {:error, annotated_error}
-  end
-
-  defp get_block_by_hash_requests(id_to_params) do
-    Enum.map(id_to_params, fn {id, %{hash: hash}} ->
-      get_block_by_hash_request(%{id: id, hash: hash, transactions: :full})
-    end)
-  end
-
-  defp get_block_by_hash_request(%{id: id} = options) do
-    request(%{id: id, method: "eth_getBlockByHash", params: get_block_by_hash_params(options)})
-  end
-
-  defp get_block_by_hash_params(%{hash: hash} = options) do
-    [hash, get_block_transactions(options)]
-  end
-
-  defp get_block_by_number_requests(id_to_params) do
-    Enum.map(id_to_params, fn {id, %{number: number}} ->
-      get_block_by_number_request(%{id: id, quantity: number, transactions: :full})
-    end)
-  end
-
-  defp get_block_by_number_request(%{id: id} = options) do
-    request(%{id: id, method: "eth_getBlockByNumber", params: get_block_by_number_params(options)})
-  end
+  defp fetch_blocks_by_params(params, request, json_rpc_named_arguments)
+       when is_list(params) and is_function(request, 1) do
+    id_to_params = id_to_params(params)
 
-  defp get_block_by_tag_request(tag) do
-    # eth_getBlockByNumber accepts either a number OR a tag
-    get_block_by_number_request(%{id: 0, tag: tag, transactions: :hashes})
-  end
-
-  defp get_block_by_number_params(options) do
-    [get_block_by_number_subject(options), get_block_transactions(options)]
-  end
-
-  defp get_block_by_number_subject(options) do
-    case {Map.fetch(options, :quantity), Map.fetch(options, :tag)} do
-      {{:ok, integer}, :error} when is_integer(integer) ->
-        integer_to_quantity(integer)
-
-      {:error, {:ok, tag}} ->
-        tag
-    end
-  end
-
-  defp get_block_transactions(%{transactions: transactions}) do
-    case transactions do
-      :full -> true
-      :hashes -> false
-    end
-  end
-
-  defp handle_get_blocks({:ok, results}, id_to_params) when is_list(results) do
-    with {:ok, next, blocks} <- reduce_results(results, id_to_params) do
-      elixir_blocks = Blocks.to_elixir(blocks)
-
-      elixir_uncles = Blocks.elixir_to_uncles(elixir_blocks)
-      elixir_transactions = Blocks.elixir_to_transactions(elixir_blocks)
-
-      block_second_degree_relations_params = Uncles.elixir_to_params(elixir_uncles)
-      transactions_params = Transactions.elixir_to_params(elixir_transactions)
-      blocks_params = Blocks.elixir_to_params(elixir_blocks)
-
-      {:ok, next,
-       %{
-         blocks: blocks_params,
-         block_second_degree_relations: block_second_degree_relations_params,
-         transactions: transactions_params
-       }}
-    end
-  end
-
-  defp handle_get_blocks({:error, _} = error, _id_to_params), do: error
-
-  defp reduce_results(results, id_to_params) do
-    Enum.reduce(results, {:ok, :more, []}, &reduce_result(&1, &2, id_to_params))
-  end
-
-  defp reduce_result(%{result: nil}, {:ok, _, blocks}, _id_to_params), do: {:ok, :end_of_chain, blocks}
-  defp reduce_result(%{result: %{} = block}, {:ok, next, blocks}, _id_to_params), do: {:ok, next, [block | blocks]}
-  defp reduce_result(%{result: _}, {:error, _} = error, _id_to_params), do: error
-
-  defp reduce_result(%{error: reason, id: id}, acc, id_to_params) do
-    data = Map.fetch!(id_to_params, id)
-    annotated_reason = Map.put(reason, :data, data)
-
-    case acc do
-      {:ok, _, _} -> {:error, [annotated_reason]}
-      {:error, reasons} -> {:error, [annotated_reason | reasons]}
+    with {:ok, responses} <-
+           id_to_params
+           |> Blocks.requests(request)
+           |> json_rpc(json_rpc_named_arguments) do
+      {:ok, Blocks.from_responses(responses, id_to_params)}
     end
   end
-
-  defp handle_get_block_by_tag({:ok, %{"number" => nil}}), do: {:error, :not_found}
-
-  defp handle_get_block_by_tag({:ok, %{"number" => quantity}}) when is_binary(quantity) do
-    {:ok, quantity_to_integer(quantity)}
-  end
-
-  # https://github.com/paritytech/parity-ethereum/pull/8281 fixed
-  #   https://github.com/paritytech/parity-ethereum/issues/8028
-  defp handle_get_block_by_tag({:ok, nil}), do: {:error, :not_found}
-
-  defp handle_get_block_by_tag({:error, %{"code" => -32602}}), do: {:error, :invalid_tag}
-  defp handle_get_block_by_tag({:error, _} = error), do: error
 end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/block.ex

@@ -68,6 +68,25 @@ defmodule EthereumJSONRPC.Block do
   """
   @type t :: %{String.t() => EthereumJSONRPC.data() | EthereumJSONRPC.hash() | EthereumJSONRPC.quantity() | nil}
 
+  def from_response(%{id: id, result: nil}, id_to_params) when is_map(id_to_params) do
+    params = Map.fetch!(id_to_params, id)
+
+    {:error, %{code: 404, message: "Not Found", data: params}}
+  end
+
+  def from_response(%{id: id, result: block}, id_to_params) when is_map(id_to_params) do
+    true = Map.has_key?(id_to_params, id)
+
+    {:ok, block}
+  end
+
+  def from_response(%{id: id, error: error}, id_to_params) when is_map(id_to_params) do
+    params = Map.fetch!(id_to_params, id)
+    annotated_error = Map.put(error, :data, params)
+
+    {:error, annotated_error}
+  end
+
   @doc """
   Converts `t:elixir/0` format to params used in `Explorer.Chain`.
 

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/block/by_hash.ex

@@ -0,0 +1,11 @@
+defmodule EthereumJSONRPC.Block.ByHash do
+  @moduledoc """
+  Block format as returned by [`eth_getBlockByHash`](https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_getblockbyhash)
+  """
+
+  @include_transactions true
+
+  def request(%{id: id, hash: hash}) do
+    EthereumJSONRPC.request(%{id: id, method: "eth_getBlockByHash", params: [hash, @include_transactions]})
+  end
+end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/block/by_number.ex

@@ -0,0 +1,11 @@
+defmodule EthereumJSONRPC.Block.ByNumber do
+  @moduledoc """
+  Block format as returned by [`eth_getBlockByNumber`](https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_getblockbyhash)
+  """
+
+  import EthereumJSONRPC, only: [integer_to_quantity: 1]
+
+  def request(%{id: id, number: number}) do
+    EthereumJSONRPC.request(%{id: id, method: "eth_getBlockByNumber", params: [integer_to_quantity(number), true]})
+  end
+end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/block/by_tag.ex

@@ -0,0 +1,25 @@
+defmodule EthereumJSONRPC.Block.ByTag do
+  @moduledoc """
+  Block format returned by [`eth_getBlockByNumber`](https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_getblockbyhash)
+  when used with a semantic tag name instead of a number.
+  """
+
+  import EthereumJSONRPC, only: [quantity_to_integer: 1]
+
+  def request(%{id: id, tag: tag}) when is_binary(tag) do
+    EthereumJSONRPC.request(%{id: id, method: "eth_getBlockByNumber", params: [tag, false]})
+  end
+
+  def number_from_result({:ok, %{"number" => nil}}), do: {:error, :not_found}
+
+  def number_from_result({:ok, %{"number" => quantity}}) when is_binary(quantity) do
+    {:ok, quantity_to_integer(quantity)}
+  end
+
+  # https://github.com/paritytech/parity-ethereum/pull/8281 fixed
+  #   https://github.com/paritytech/parity-ethereum/issues/8028
+  def number_from_result({:ok, nil}), do: {:error, :not_found}
+
+  def number_from_result({:error, %{"code" => -32602}}), do: {:error, :invalid_tag}
+  def number_from_result({:error, _} = error), do: error
+end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/blocks.ex

@@ -4,11 +4,59 @@ defmodule EthereumJSONRPC.Blocks do
   and [`eth_getBlockByNumber`](https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_getblockbynumber) from batch requests.
   """
 
-  alias EthereumJSONRPC.{Block, Transactions, Uncles}
+  alias EthereumJSONRPC.{Block, Transactions, Transport, Uncles}
 
   @type elixir :: [Block.elixir()]
   @type params :: [Block.params()]
-  @type t :: [Block.t()]
+  @type t :: %__MODULE__{
+          blocks_params: [map()],
+          block_second_degree_relations_params: [map()],
+          transactions_params: [map()],
+          errors: [Transport.error()]
+        }
+
+  defstruct blocks_params: [],
+            block_second_degree_relations_params: [],
+            transactions_params: [],
+            errors: []
+
+  def requests(id_to_params, request) when is_map(id_to_params) and is_function(request, 1) do
+    Enum.map(id_to_params, fn {id, params} ->
+      params
+      |> Map.put(:id, id)
+      |> request.()
+    end)
+  end
+
+  @spec from_responses(list(), map()) :: t()
+  def from_responses(responses, id_to_params) when is_list(responses) and is_map(id_to_params) do
+    %{errors: errors, blocks: blocks} =
+      responses
+      |> Enum.map(&Block.from_response(&1, id_to_params))
+      |> Enum.reduce(%{errors: [], blocks: []}, fn
+        {:ok, block}, %{blocks: blocks} = acc ->
+          %{acc | blocks: [block | blocks]}
+
+        {:error, error}, %{errors: errors} = acc ->
+          %{acc | errors: [error | errors]}
+      end)
+
+    elixir_blocks = to_elixir(blocks)
+
+    elixir_uncles = elixir_to_uncles(elixir_blocks)
+    elixir_transactions = elixir_to_transactions(elixir_blocks)
+
+    block_second_degree_relations_params = Uncles.elixir_to_params(elixir_uncles)
+    transactions_params = Transactions.elixir_to_params(elixir_transactions)
+    blocks_params = elixir_to_params(elixir_blocks)
+
+    %__MODULE__{
+      errors: errors,
+      blocks_params: blocks_params,
+      block_second_degree_relations_params: block_second_degree_relations_params,
+      transactions_params: transactions_params
+    }
+  end
 
   @doc """
   Converts `t:elixir/0` elements to params used by `Explorer.Chain.Block.changeset/2`.
@@ -282,7 +330,7 @@ defmodule EthereumJSONRPC.Blocks do
         }
       ]
   """
-  @spec to_elixir(t) :: elixir
+  @spec to_elixir([Block.t()]) :: elixir
   def to_elixir(blocks) when is_list(blocks) do
     Enum.map(blocks, &Block.to_elixir/1)
   end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/fetched_balance.ex

@@ -0,0 +1,62 @@
+defmodule EthereumJSONRPC.FetchedBalance do
+  @moduledoc """
+  A single balance fetched from `eth_getBalance`.
+  """
+
+  import EthereumJSONRPC, only: [quantity_to_integer: 1]
+
+  @type params :: %{address_hash: EthereumJSONRPC.hash(), block_number: non_neg_integer(), value: non_neg_integer()}
+  @type error :: %{code: integer(), message: String.t(), data: %{block_quantity: String.t(), hash: String.t()}}
+
+  @doc """
+  Converts `response` to balance params or annotated error.
+  """
+
+  @spec from_response(%{id: id, result: String.t()}, %{id => %{block_quantity: block_quantity, hash_data: hash_data}}) ::
+          {:ok, params()}
+        when id: non_neg_integer(), block_quantity: String.t(), hash_data: String.t()
+  def from_response(%{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)
+
+    {:ok,
+     %{
+       address_hash: hash_data,
+       block_number: quantity_to_integer(block_quantity),
+       value: quantity_to_integer(fetched_balance_quantity)
+     }}
+  end
+
+  @spec from_response(
+          %{
+            id: id,
+            error: %{code: code, message: message}
+          },
+          %{id => %{block_quantity: block_quantity, hash_data: hash_data}}
+        ) :: {:error, %{code: code, message: message, data: %{block_quantity: block_quantity, hash: hash_data}}}
+        when id: non_neg_integer(),
+             code: integer(),
+             message: String.t(),
+             block_quantity: String.t(),
+             hash_data: String.t()
+  def from_response(%{id: id, error: %{code: code, message: message} = error}, id_to_params)
+      when is_integer(code) and is_binary(message) and is_map(id_to_params) do
+    %{block_quantity: block_quantity, hash_data: hash_data} = Map.fetch!(id_to_params, id)
+
+    annotated_error = Map.put(error, :data, %{block_quantity: block_quantity, hash_data: hash_data})
+
+    {:error, annotated_error}
+  end
+
+  @spec request(%{id: id, block_quantity: block_quantity, hash_data: hash_data}) :: %{
+          jsonrpc: String.t(),
+          id: id,
+          method: String.t(),
+          params: [hash_data | block_quantity]
+        }
+        when id: EthereumJSONRPC.request_id(),
+             block_quantity: EthereumJSONRPC.quantity(),
+             hash_data: EthereumJSONRPC.hash()
+  def request(%{id: id, block_quantity: block_quantity, hash_data: hash_data}) do
+    EthereumJSONRPC.request(%{id: id, method: "eth_getBalance", params: [hash_data, block_quantity]})
+  end
+end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/fetched_balances.ex

@@ -0,0 +1,49 @@
+defmodule EthereumJSONRPC.FetchedBalances do
+  @moduledoc """
+  Balance params and errors from a batch request from `eth_getBalance`.
+  """
+
+  alias EthereumJSONRPC.FetchedBalance
+
+  defstruct params_list: [],
+            errors: []
+
+  @typedoc """
+   * `params_list` - all the balance params from requests that succeeded in the batch.
+   * `errors` - all the errors from requests that failed in the batch.
+  """
+  @type t :: %__MODULE__{params_list: [FetchedBalance.params()], errors: [FetchedBalance.error()]}
+
+  @doc """
+  Converts `responses` to `t/0`.
+  """
+  def from_responses(responses, id_to_params) do
+    responses
+    |> Enum.map(&FetchedBalance.from_response(&1, id_to_params))
+    |> Enum.reduce(
+      %__MODULE__{},
+      fn
+        {:ok, params}, %__MODULE__{params_list: params_list} = acc ->
+          %__MODULE__{acc | params_list: [params | params_list]}
+
+        {:error, reason}, %__MODULE__{errors: errors} = acc ->
+          %__MODULE__{acc | errors: [reason | errors]}
+      end
+    )
+  end
+
+  @doc """
+  `eth_getBalance` requests for `id_to_params`.
+  """
+  @spec requests(%{id => %{block_quantity: block_quantity, hash_data: hash_data}}) :: [
+          %{jsonrpc: String.t(), id: id, method: String.t(), params: [hash_data | block_quantity]}
+        ]
+        when id: EthereumJSONRPC.request_id(),
+             block_quantity: EthereumJSONRPC.quantity(),
+             hash_data: EthereumJSONRPC.hash()
+  def 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}} ->
+      FetchedBalance.request(%{id: id, block_quantity: block_quantity, hash_data: hash_data})
+    end)
+  end
+end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/fetched_beneficiaries.ex

@@ -0,0 +1,16 @@
+defmodule EthereumJSONRPC.FetchedBeneficiaries do
+  @moduledoc """
+  Balance params and errors from a batch request to fetch beneficiaries.
+  """
+
+  alias EthereumJSONRPC.FetchedBeneficiary
+
+  defstruct params_set: MapSet.new(),
+            errors: []
+
+  @typedoc """
+   * `params_set` - all the balance request params from requests that succeeded in the batch.
+   * `errors` - all the errors from requests that failed in the batch.
+  """
+  @type t :: %__MODULE__{params_set: MapSet.t(FetchedBeneficiary.params()), errors: [FetchedBeneficiary.error()]}
+end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/fetched_beneficiary.ex

@@ -0,0 +1,8 @@
+defmodule EthereumJSONRPC.FetchedBeneficiary do
+  @moduledoc """
+  A single balance request params for the beneficiary of a block.
+  """
+
+  @type params :: %{address_hash: EthereumJSONRPC.hash(), block_number: non_neg_integer()}
+  @type error :: %{code: integer(), message: String.t(), data: %{block_number: non_neg_integer()}}
+end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/parity.ex

@@ -3,35 +3,26 @@ defmodule EthereumJSONRPC.Parity do
   Ethereum JSONRPC methods that are only supported by [Parity](https://wiki.parity.io/).
   """
 
-  import EthereumJSONRPC, only: [id_to_params: 1, json_rpc: 2, request: 1]
+  import EthereumJSONRPC, only: [id_to_params: 1, integer_to_quantity: 1, json_rpc: 2, request: 1]
 
-  alias EthereumJSONRPC.Parity.Traces
+  alias EthereumJSONRPC.Parity.{FetchedBeneficiaries, Traces}
   alias EthereumJSONRPC.{Transaction, Transactions}
 
   @behaviour EthereumJSONRPC.Variant
 
   @impl EthereumJSONRPC.Variant
-  def fetch_beneficiaries(block_range, json_rpc_named_arguments) do
-    Enum.reduce(
-      Enum.with_index(block_range),
-      {:ok, MapSet.new()},
-      fn
-        {block_number, index}, {:ok, beneficiaries} ->
-          quantity = EthereumJSONRPC.integer_to_quantity(block_number)
-
-          case trace_block(index, quantity, json_rpc_named_arguments) do
-            {:ok, traces} when is_list(traces) ->
-              new_beneficiaries = extract_beneficiaries(traces)
-              {:ok, MapSet.union(new_beneficiaries, beneficiaries)}
+  def fetch_beneficiaries(_.._ = block_range, json_rpc_named_arguments) when is_list(json_rpc_named_arguments) do
+    id_to_params =
+      block_range
+      |> block_range_to_params_list()
+      |> id_to_params()
 
-            _ ->
-              {:error, "Error fetching block reward contract beneficiaries"}
-          end
-
-        _, {:error, _} = error ->
-          error
-      end
-    )
+    with {:ok, responses} <-
+           id_to_params
+           |> FetchedBeneficiaries.requests()
+           |> json_rpc(json_rpc_named_arguments) do
+      {:ok, FetchedBeneficiaries.from_responses(responses, id_to_params)}
+    end
   end
 
   @doc """
@@ -72,25 +63,8 @@ defmodule EthereumJSONRPC.Parity do
     end
   end
 
-  defp extract_beneficiaries(traces) when is_list(traces) do
-    Enum.reduce(traces, MapSet.new(), fn
-      %{"type" => "reward", "blockNumber" => block_number, "action" => %{"author" => author}}, beneficiaries ->
-        beneficiary = %{
-          block_number: block_number,
-          address_hash: author
-        }
-
-        MapSet.put(beneficiaries, beneficiary)
-
-      _, beneficiaries ->
-        beneficiaries
-    end)
-  end
-
-  defp trace_block(index, quantity, json_rpc_named_arguments) do
-    %{id: index, method: "trace_block", params: [quantity]}
-    |> request()
-    |> json_rpc(json_rpc_named_arguments)
+  defp block_range_to_params_list(_.._ = block_range) do
+    Enum.map(block_range, &%{block_quantity: integer_to_quantity(&1)})
   end
 
   defp trace_replay_transaction_responses_to_internal_transactions_params(responses, id_to_params)

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/parity/fetched_beneficiaries.ex

@@ -0,0 +1,94 @@
+defmodule EthereumJSONRPC.Parity.FetchedBeneficiaries do
+  @moduledoc """
+  Beneficiaries and errors from batch requests to `trace_block`.
+  """
+
+  import EthereumJSONRPC, only: [quantity_to_integer: 1]
+
+  @doc """
+  Converts `responses` to `t/0`.
+  """
+  def from_responses(responses, id_to_params) when is_list(responses) and is_map(id_to_params) do
+    responses
+    |> Enum.map(&response_to_params_set(&1, id_to_params))
+    |> Enum.reduce(
+      %EthereumJSONRPC.FetchedBeneficiaries{},
+      fn
+        {:ok, params_set}, %EthereumJSONRPC.FetchedBeneficiaries{params_set: acc_params_set} = acc ->
+          %EthereumJSONRPC.FetchedBeneficiaries{acc | params_set: MapSet.union(acc_params_set, params_set)}
+
+        {:error, reason}, %EthereumJSONRPC.FetchedBeneficiaries{errors: errors} = acc ->
+          %EthereumJSONRPC.FetchedBeneficiaries{acc | errors: [reason | errors]}
+      end
+    )
+  end
+
+  @doc """
+  `trace_block` requests for `id_to_params`.
+  """
+  def requests(id_to_params) when is_map(id_to_params) do
+    Enum.map(id_to_params, fn {id, %{block_quantity: block_quantity}} ->
+      request(%{id: id, block_quantity: block_quantity})
+    end)
+  end
+
+  @spec response_to_params_set(%{id: id, result: nil}, %{id => %{block_quantity: block_quantity}}) ::
+          {:error, %{code: 404, message: String.t(), data: %{block_quantity: block_quantity}}}
+        when id: non_neg_integer(), block_quantity: String.t()
+  defp response_to_params_set(%{id: id, result: nil}, id_to_params) when is_map(id_to_params) do
+    %{block_quantity: block_quantity} = Map.fetch!(id_to_params, id)
+
+    {:error, %{code: 404, message: "Not Found", data: %{block_quantity: block_quantity}}}
+  end
+
+  @spec response_to_params_set(%{id: id, result: list(map())}, %{id => %{block_quantity: block_quantity}}) ::
+          {:ok, MapSet.t(EthereumJSONRPC.FetchedBeneficiary.params())}
+        when id: non_neg_integer(), block_quantity: String.t()
+  defp response_to_params_set(%{id: id, result: traces}, id_to_params) when is_list(traces) and is_map(id_to_params) do
+    %{block_quantity: block_quantity} = Map.fetch!(id_to_params, id)
+    block_number = quantity_to_integer(block_quantity)
+    params_set = traces_to_params_set(traces, block_number)
+
+    {:ok, params_set}
+  end
+
+  @spec response_to_params_set(%{id: id, error: %{code: code, message: message}}, %{
+          id => %{block_quantity: block_quantity}
+        }) :: {:error, %{code: code, message: message, data: %{block_quantity: block_quantity}}}
+        when id: non_neg_integer(), code: integer(), message: String.t(), block_quantity: String.t()
+  defp response_to_params_set(%{id: id, error: error}, id_to_params) when is_map(id_to_params) do
+    %{block_quantity: block_quantity} = Map.fetch!(id_to_params, id)
+
+    annotated_error = Map.put(error, :data, %{block_quantity: block_quantity})
+
+    {:error, annotated_error}
+  end
+
+  defp request(%{id: id, block_quantity: block_quantity}) when is_integer(id) and is_binary(block_quantity) do
+    EthereumJSONRPC.request(%{id: id, method: "trace_block", params: [block_quantity]})
+  end
+
+  defp traces_to_params_set(traces, block_number) when is_list(traces) and is_integer(block_number) do
+    Enum.reduce(traces, MapSet.new(), fn trace, acc ->
+      MapSet.union(acc, trace_to_params_set(trace, block_number))
+    end)
+  end
+
+  defp trace_to_params_set(%{"action" => %{"callType" => _}, "blockNumber" => block_number}, block_number),
+    do: MapSet.new()
+
+  defp trace_to_params_set(%{"type" => type, "blockNumber" => block_number}, block_number)
+       when type in ~w(create suicide),
+       do: MapSet.new()
+
+  defp trace_to_params_set(
+         %{
+           "action" => %{"rewardType" => reward_type, "author" => address_hash_data},
+           "blockNumber" => block_number
+         },
+         block_number
+       )
+       when is_integer(block_number) and reward_type in ~w(block external uncle) do
+    MapSet.new([%{address_hash: address_hash_data, block_number: block_number}])
+  end
+end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/variant.ex

@@ -4,7 +4,7 @@ defmodule EthereumJSONRPC.Variant do
   Ethereum JSONRPC API.  The variant callbacks abstract over this difference.
   """
 
-  alias EthereumJSONRPC.Transaction
+  alias EthereumJSONRPC.{FetchedBeneficiaries, Transaction}
 
   @typedoc """
   A module that implements the `EthereumJSONRPC.Variant` behaviour callbacks.
@@ -22,12 +22,12 @@ defmodule EthereumJSONRPC.Variant do
 
   ## Returns
 
-   * `{:ok, #MapSet<[%{...}]>}` - beneficiaries were successfully fetched
-   * `{:error, reason}` - there was one or more errors with `reason` in fetching the beneficiaries
+   * `{:ok, %EthereumJSONRPC.FetchedBeneficiaries{params_list: [%{address_hash: address_hash, block_number: block_number}], errors: %{code: code, message: message, data: %{block_number: block_number}}}` - some beneficiaries were successfully fetched and some may have had errors.
+   * `{:error, reason}` - there was an error at the transport level
    * `:ignore` - the variant does not support fetching beneficiaries
   """
   @callback fetch_beneficiaries(Range.t(), EthereumJSONRPC.json_rpc_named_arguments()) ::
-              {:ok, MapSet.t()} | {:error, reason :: term} | :ignore
+              {:ok, FetchedBeneficiaries.t()} | {:error, reason :: term} | :ignore
 
   @doc """
   Fetches the `t:Explorer.Chain.InternalTransaction.changeset/2` params from the variant of the Ethereum JSONRPC API.

apps/ethereum_jsonrpc/test/ethereum_jsonrpc/parity_test.exs

@@ -5,6 +5,8 @@ defmodule EthereumJSONRPC.ParityTest do
   import EthereumJSONRPC, only: [integer_to_quantity: 1]
   import Mox
 
+  alias EthereumJSONRPC.FetchedBeneficiaries
+
   setup :verify_on_exit!
 
   doctest EthereumJSONRPC.Parity
@@ -245,53 +247,54 @@ defmodule EthereumJSONRPC.ParityTest do
       hash2 = "0x523b6539ff08d72a6c8bb598af95bf50c1ea839c"
 
       if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
-        expect(EthereumJSONRPC.Mox, :json_rpc, fn %{params: [^block_quantity]}, _options ->
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn [%{id: id, params: [^block_quantity]}], _options ->
           {:ok,
            [
              %{
-               "action" => %{
-                 "author" => hash1,
-                 "rewardType" => "block",
-                 "value" => "0xde0b6b3a7640000"
-               },
-               "blockHash" => "0x52a8d2185282506ce681364d2aa0c085ba45fdeb5d6c0ddec1131617a71ee2ca",
-               "blockNumber" => block_number,
-               "result" => nil,
-               "subtraces" => 0,
-               "traceAddress" => [],
-               "transactionHash" => nil,
-               "transactionPosition" => nil,
-               "type" => "reward"
-             },
-             %{
-               "action" => %{
-                 "author" => hash2,
-                 "rewardType" => "block",
-                 "value" => "0xde0b6b3a7640000"
-               },
-               "blockHash" => "0x52a8d2185282506ce681364d2aa0c085ba45fdeb5d6c0ddec1131617a71ee2ca",
-               "blockNumber" => block_number,
-               "result" => nil,
-               "subtraces" => 0,
-               "traceAddress" => [],
-               "transactionHash" => nil,
-               "transactionPosition" => nil,
-               "type" => "reward"
+               id: id,
+               result: [
+                 %{
+                   "action" => %{
+                     "author" => hash1,
+                     "rewardType" => "block",
+                     "value" => "0xde0b6b3a7640000"
+                   },
+                   "blockHash" => "0x52a8d2185282506ce681364d2aa0c085ba45fdeb5d6c0ddec1131617a71ee2ca",
+                   "blockNumber" => block_number,
+                   "result" => nil,
+                   "subtraces" => 0,
+                   "traceAddress" => [],
+                   "transactionHash" => nil,
+                   "transactionPosition" => nil,
+                   "type" => "reward"
+                 },
+                 %{
+                   "action" => %{
+                     "author" => hash2,
+                     "rewardType" => "block",
+                     "value" => "0xde0b6b3a7640000"
+                   },
+                   "blockHash" => "0x52a8d2185282506ce681364d2aa0c085ba45fdeb5d6c0ddec1131617a71ee2ca",
+                   "blockNumber" => block_number,
+                   "result" => nil,
+                   "subtraces" => 0,
+                   "traceAddress" => [],
+                   "transactionHash" => nil,
+                   "transactionPosition" => nil,
+                   "type" => "reward"
+                 }
+               ]
              }
            ]}
         end)
       end
 
-      expected_beneficiaries =
-        MapSet.new([
-          %{block_number: block_number, address_hash: hash2},
-          %{block_number: block_number, address_hash: hash1}
-        ])
-
-      {:ok, fetched_beneficiaries} =
-        EthereumJSONRPC.Parity.fetch_beneficiaries(5_080_887..5_080_887, json_rpc_named_arguments)
+      assert {:ok, %FetchedBeneficiaries{params_set: params_set}} =
+               EthereumJSONRPC.Parity.fetch_beneficiaries(5_080_887..5_080_887, json_rpc_named_arguments)
 
-      assert fetched_beneficiaries == expected_beneficiaries
+      assert Enum.count(params_set) == 2
+      assert %{block_number: block_number, address_hash: hash2} in params_set
+      assert %{block_number: block_number, address_hash: hash1} in params_set
     end
 
     test "with 'external' 'rewardType'", %{
@@ -303,81 +306,69 @@ defmodule EthereumJSONRPC.ParityTest do
       hash2 = "0x523b6539ff08d72a6c8bb598af95bf50c1ea839c"
 
       if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
-        expect(EthereumJSONRPC.Mox, :json_rpc, fn %{params: [^block_quantity]}, _options ->
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn [%{id: id, params: [^block_quantity]}], _options ->
           {:ok,
            [
              %{
-               "action" => %{
-                 "author" => hash1,
-                 "rewardType" => "external",
-                 "value" => "0xde0b6b3a7640000"
-               },
-               "blockHash" => "0xf19a4ea2bb4f2d8839f4c3ec11e0e86c29d57799d7073713958fe1990e197cf5",
-               "blockNumber" => 5_609_295,
-               "result" => nil,
-               "subtraces" => 0,
-               "traceAddress" => [],
-               "transactionHash" => nil,
-               "transactionPosition" => nil,
-               "type" => "reward"
-             },
-             %{
-               "action" => %{
-                 "author" => hash2,
-                 "rewardType" => "external",
-                 "value" => "0xde0b6b3a7640000"
-               },
-               "blockHash" => "0xf19a4ea2bb4f2d8839f4c3ec11e0e86c29d57799d7073713958fe1990e197cf5",
-               "blockNumber" => 5_609_295,
-               "result" => nil,
-               "subtraces" => 0,
-               "traceAddress" => [],
-               "transactionHash" => nil,
-               "transactionPosition" => nil,
-               "type" => "reward"
+               id: id,
+               result: [
+                 %{
+                   "action" => %{
+                     "author" => hash1,
+                     "rewardType" => "external",
+                     "value" => "0xde0b6b3a7640000"
+                   },
+                   "blockHash" => "0xf19a4ea2bb4f2d8839f4c3ec11e0e86c29d57799d7073713958fe1990e197cf5",
+                   "blockNumber" => 5_609_295,
+                   "result" => nil,
+                   "subtraces" => 0,
+                   "traceAddress" => [],
+                   "transactionHash" => nil,
+                   "transactionPosition" => nil,
+                   "type" => "reward"
+                 },
+                 %{
+                   "action" => %{
+                     "author" => hash2,
+                     "rewardType" => "external",
+                     "value" => "0xde0b6b3a7640000"
+                   },
+                   "blockHash" => "0xf19a4ea2bb4f2d8839f4c3ec11e0e86c29d57799d7073713958fe1990e197cf5",
+                   "blockNumber" => 5_609_295,
+                   "result" => nil,
+                   "subtraces" => 0,
+                   "traceAddress" => [],
+                   "transactionHash" => nil,
+                   "transactionPosition" => nil,
+                   "type" => "reward"
+                 }
+               ]
              }
            ]}
         end)
       end
 
-      expected_beneficiaries =
-        MapSet.new([
-          %{block_number: block_number, address_hash: hash2},
-          %{block_number: block_number, address_hash: hash1}
-        ])
+      assert {:ok, %FetchedBeneficiaries{params_set: params_set, errors: []}} =
+               EthereumJSONRPC.Parity.fetch_beneficiaries(5_609_295..5_609_295, json_rpc_named_arguments)
 
-      {:ok, fetched_beneficiaries} =
-        EthereumJSONRPC.Parity.fetch_beneficiaries(5_609_295..5_609_295, json_rpc_named_arguments)
-
-      assert fetched_beneficiaries == expected_beneficiaries
+      assert Enum.count(params_set) == 2
+      assert %{block_number: block_number, address_hash: hash1} in params_set
+      assert %{block_number: block_number, address_hash: hash2} in params_set
     end
 
     test "with no rewards, returns {:ok, []}", %{
       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, []}
-        end)
-
-        {:ok, fetched_beneficiaries} =
-          EthereumJSONRPC.Parity.fetch_beneficiaries(5_080_887..5_080_887, json_rpc_named_arguments)
-
-        assert fetched_beneficiaries == MapSet.new()
-      end
-    end
-
-    test "with nil rewards, returns {:error, reason}", %{
-      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, nil}
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn requests, _options when is_list(requests) ->
+          responses = Enum.map(requests, fn %{id: id} -> %{id: id, result: []} end)
+          {:ok, responses}
         end)
 
-        result = EthereumJSONRPC.Parity.fetch_beneficiaries(5_080_887..5_080_887, json_rpc_named_arguments)
+        assert {:ok, %FetchedBeneficiaries{params_set: params_set}} =
+                 EthereumJSONRPC.Parity.fetch_beneficiaries(5_080_887..5_080_887, json_rpc_named_arguments)
 
-        assert result == {:error, "Error fetching block reward contract beneficiaries"}
+        assert Enum.empty?(params_set)
       end
     end
 
@@ -390,71 +381,72 @@ defmodule EthereumJSONRPC.ParityTest do
       hash2 = "0x523b6539ff08d72a6c8bb598af95bf50c1ea839c"
 
       if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
-        expect(EthereumJSONRPC.Mox, :json_rpc, fn %{params: [^block_quantity]}, _options ->
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn [%{id: id, params: [^block_quantity]}], _options ->
           {:ok,
            [
              %{
-               "action" => %{
-                 "callType" => "call",
-                 "from" => "0x95426f2bc716022fcf1def006dbc4bb81f5b5164",
-                 "gas" => "0x0",
-                 "input" => "0x",
-                 "to" => "0xe797a1da01eb0f951e0e400f9343de9d17a06bac",
-                 "value" => "0x4a817c800"
-               },
-               "blockHash" => "0x6659a4926d833a7eab74379fa647ec74c9f5e65f8029552a35264126560f300a",
-               "blockNumber" => block_number,
-               "result" => %{"gasUsed" => "0x0", "output" => "0x"},
-               "subtraces" => 0,
-               "traceAddress" => [],
-               "transactionHash" => "0x5acf90f846b8216bdbc309cf4eb24adc69d730bf29304dc0e740cf6df850666e",
-               "transactionPosition" => 0,
-               "type" => "call"
-             },
-             %{
-               "action" => %{
-                 "author" => hash1,
-                 "rewardType" => "block",
-                 "value" => "0xde0b6b3a7640000"
-               },
-               "blockHash" => "0x6659a4926d833a7eab74379fa647ec74c9f5e65f8029552a35264126560f300a",
-               "blockNumber" => block_number,
-               "result" => nil,
-               "subtraces" => 0,
-               "traceAddress" => [],
-               "transactionHash" => nil,
-               "transactionPosition" => nil,
-               "type" => "reward"
-             },
-             %{
-               "action" => %{
-                 "author" => hash2,
-                 "rewardType" => "block",
-                 "value" => "0xde0b6b3a7640000"
-               },
-               "blockHash" => "0x6659a4926d833a7eab74379fa647ec74c9f5e65f8029552a35264126560f300a",
-               "blockNumber" => block_number,
-               "result" => nil,
-               "subtraces" => 0,
-               "traceAddress" => [],
-               "transactionHash" => nil,
-               "transactionPosition" => nil,
-               "type" => "reward"
+               id: id,
+               result: [
+                 %{
+                   "action" => %{
+                     "callType" => "call",
+                     "from" => "0x95426f2bc716022fcf1def006dbc4bb81f5b5164",
+                     "gas" => "0x0",
+                     "input" => "0x",
+                     "to" => "0xe797a1da01eb0f951e0e400f9343de9d17a06bac",
+                     "value" => "0x4a817c800"
+                   },
+                   "blockHash" => "0x6659a4926d833a7eab74379fa647ec74c9f5e65f8029552a35264126560f300a",
+                   "blockNumber" => block_number,
+                   "result" => %{"gasUsed" => "0x0", "output" => "0x"},
+                   "subtraces" => 0,
+                   "traceAddress" => [],
+                   "transactionHash" => "0x5acf90f846b8216bdbc309cf4eb24adc69d730bf29304dc0e740cf6df850666e",
+                   "transactionPosition" => 0,
+                   "type" => "call"
+                 },
+                 %{
+                   "action" => %{
+                     "author" => hash1,
+                     "rewardType" => "block",
+                     "value" => "0xde0b6b3a7640000"
+                   },
+                   "blockHash" => "0x6659a4926d833a7eab74379fa647ec74c9f5e65f8029552a35264126560f300a",
+                   "blockNumber" => block_number,
+                   "result" => nil,
+                   "subtraces" => 0,
+                   "traceAddress" => [],
+                   "transactionHash" => nil,
+                   "transactionPosition" => nil,
+                   "type" => "reward"
+                 },
+                 %{
+                   "action" => %{
+                     "author" => hash2,
+                     "rewardType" => "block",
+                     "value" => "0xde0b6b3a7640000"
+                   },
+                   "blockHash" => "0x6659a4926d833a7eab74379fa647ec74c9f5e65f8029552a35264126560f300a",
+                   "blockNumber" => block_number,
+                   "result" => nil,
+                   "subtraces" => 0,
+                   "traceAddress" => [],
+                   "transactionHash" => nil,
+                   "transactionPosition" => nil,
+                   "type" => "reward"
+                 }
+               ]
              }
            ]}
         end)
       end
 
-      expected_beneficiaries =
-        MapSet.new([
-          %{block_number: block_number, address_hash: hash2},
-          %{block_number: block_number, address_hash: hash1}
-        ])
-
-      {:ok, fetched_beneficiaries} =
-        EthereumJSONRPC.Parity.fetch_beneficiaries(5_077_429..5_077_429, json_rpc_named_arguments)
+      assert {:ok, %FetchedBeneficiaries{params_set: params_set}} =
+               EthereumJSONRPC.Parity.fetch_beneficiaries(5_077_429..5_077_429, json_rpc_named_arguments)
 
-      assert fetched_beneficiaries == expected_beneficiaries
+      assert Enum.count(params_set) == 2
+      assert %{block_number: block_number, address_hash: hash2} in params_set
+      assert %{block_number: block_number, address_hash: hash1} in params_set
     end
 
     test "with multiple blocks with repeat beneficiaries", %{
@@ -469,87 +461,92 @@ defmodule EthereumJSONRPC.ParityTest do
       hash3 = "0x523b6539ff08d72a6c8bb598af95bf50c1ea839c"
 
       if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
-        expect(EthereumJSONRPC.Mox, :json_rpc, 2, fn
-          %{params: [^block_quantity1]} = _json, _options ->
-            {:ok,
-             [
-               %{
-                 "action" => %{
-                   "author" => hash1,
-                   "rewardType" => "block",
-                   "value" => "0xde0b6b3a7640000"
-                 },
-                 "blockNumber" => block_number1,
-                 "result" => nil,
-                 "subtraces" => 0,
-                 "traceAddress" => [],
-                 "transactionHash" => nil,
-                 "transactionPosition" => nil,
-                 "type" => "reward"
-               },
-               %{
-                 "action" => %{
-                   "author" => hash3,
-                   "rewardType" => "block",
-                   "value" => "0xde0b6b3a7640000"
-                 },
-                 "blockNumber" => block_number1,
-                 "result" => nil,
-                 "subtraces" => 0,
-                 "traceAddress" => [],
-                 "transactionHash" => nil,
-                 "transactionPosition" => nil,
-                 "type" => "reward"
-               }
-             ]}
-
-          %{params: [^block_quantity2]} = _json, _options ->
-            {:ok,
-             [
-               %{
-                 "action" => %{
-                   "author" => hash2,
-                   "rewardType" => "block",
-                   "value" => "0xde0b6b3a7640000"
-                 },
-                 "blockNumber" => block_number2,
-                 "result" => nil,
-                 "subtraces" => 0,
-                 "traceAddress" => [],
-                 "transactionHash" => nil,
-                 "transactionPosition" => nil,
-                 "type" => "reward"
-               },
-               %{
-                 "action" => %{
-                   "author" => hash3,
-                   "rewardType" => "block",
-                   "value" => "0xde0b6b3a7640000"
-                 },
-                 "blockNumber" => block_number2,
-                 "result" => nil,
-                 "subtraces" => 0,
-                 "traceAddress" => [],
-                 "transactionHash" => nil,
-                 "transactionPosition" => nil,
-                 "type" => "reward"
-               }
-             ]}
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn requests, _options when is_list(requests) ->
+          responses =
+            Enum.map(requests, fn
+              %{id: id, params: [^block_quantity1]} ->
+                %{
+                  id: id,
+                  result: [
+                    %{
+                      "action" => %{
+                        "author" => hash1,
+                        "rewardType" => "block",
+                        "value" => "0xde0b6b3a7640000"
+                      },
+                      "blockNumber" => block_number1,
+                      "result" => nil,
+                      "subtraces" => 0,
+                      "traceAddress" => [],
+                      "transactionHash" => nil,
+                      "transactionPosition" => nil,
+                      "type" => "reward"
+                    },
+                    %{
+                      "action" => %{
+                        "author" => hash3,
+                        "rewardType" => "block",
+                        "value" => "0xde0b6b3a7640000"
+                      },
+                      "blockNumber" => block_number1,
+                      "result" => nil,
+                      "subtraces" => 0,
+                      "traceAddress" => [],
+                      "transactionHash" => nil,
+                      "transactionPosition" => nil,
+                      "type" => "reward"
+                    }
+                  ]
+                }
+
+              %{id: id, params: [^block_quantity2]} ->
+                %{
+                  id: id,
+                  result: [
+                    %{
+                      "action" => %{
+                        "author" => hash2,
+                        "rewardType" => "block",
+                        "value" => "0xde0b6b3a7640000"
+                      },
+                      "blockNumber" => block_number2,
+                      "result" => nil,
+                      "subtraces" => 0,
+                      "traceAddress" => [],
+                      "transactionHash" => nil,
+                      "transactionPosition" => nil,
+                      "type" => "reward"
+                    },
+                    %{
+                      "action" => %{
+                        "author" => hash3,
+                        "rewardType" => "block",
+                        "value" => "0xde0b6b3a7640000"
+                      },
+                      "blockNumber" => block_number2,
+                      "result" => nil,
+                      "subtraces" => 0,
+                      "traceAddress" => [],
+                      "transactionHash" => nil,
+                      "transactionPosition" => nil,
+                      "type" => "reward"
+                    }
+                  ]
+                }
+            end)
+
+          {:ok, responses}
         end)
       end
 
-      expected_beneficiaries =
-        MapSet.new([
-          %{block_number: block_number1, address_hash: hash3},
-          %{block_number: block_number2, address_hash: hash3},
-          %{block_number: block_number2, address_hash: hash2},
-          %{block_number: block_number1, address_hash: hash1}
-        ])
-
-      {:ok, fetched_beneficiaries} =
-        EthereumJSONRPC.Parity.fetch_beneficiaries(5_080_886..5_080_887, json_rpc_named_arguments)
+      assert {:ok, %FetchedBeneficiaries{params_set: params_set}} =
+               EthereumJSONRPC.Parity.fetch_beneficiaries(5_080_886..5_080_887, json_rpc_named_arguments)
 
-      assert fetched_beneficiaries == expected_beneficiaries
+      assert Enum.count(params_set) == 4
+      assert %{block_number: block_number1, address_hash: hash3} in params_set
+      assert %{block_number: block_number2, address_hash: hash3} in params_set
+      assert %{block_number: block_number2, address_hash: hash2} in params_set
+      assert %{block_number: block_number1, address_hash: hash1} in params_set
     end
 
     test "with error, returns {:error, reason}", %{
@@ -560,9 +557,8 @@ defmodule EthereumJSONRPC.ParityTest do
           {:error, "oops"}
         end)
 
-        result = EthereumJSONRPC.Parity.fetch_beneficiaries(5_080_887..5_080_887, json_rpc_named_arguments)
-
-        assert result == {:error, "Error fetching block reward contract beneficiaries"}
+        assert {:error, "oops"} =
+                 EthereumJSONRPC.Parity.fetch_beneficiaries(5_080_887..5_080_887, json_rpc_named_arguments)
       end
     end
   end

apps/ethereum_jsonrpc/test/ethereum_jsonrpc_test.exs

@@ -4,7 +4,7 @@ defmodule EthereumJSONRPCTest do
   import EthereumJSONRPC.Case
   import Mox
 
-  alias EthereumJSONRPC.Subscription
+  alias EthereumJSONRPC.{Blocks, FetchedBalances, FetchedBeneficiaries, Subscription}
   alias EthereumJSONRPC.WebSocket.WebSocketClient
 
   setup :verify_on_exit!
@@ -37,16 +37,18 @@ defmodule EthereumJSONRPCTest do
                json_rpc_named_arguments
              ) ==
                {:ok,
-                [
-                  %{
-                    address_hash: hash,
-                    block_number: 1,
-                    value: expected_fetched_balance
-                  }
-                ]}
+                %FetchedBalances{
+                  params_list: [
+                    %{
+                      address_hash: hash,
+                      block_number: 1,
+                      value: expected_fetched_balance
+                    }
+                  ]
+                }}
     end
 
-    test "with all invalid hash_data returns {:error, reasons}", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+    test "with all invalid hash_data returns errors", %{json_rpc_named_arguments: json_rpc_named_arguments} do
       variant = Keyword.fetch!(json_rpc_named_arguments, :variant)
 
       expected_message =
@@ -76,18 +78,21 @@ defmodule EthereumJSONRPCTest do
         end)
       end
 
-      assert {:error,
-              [
-                %{
-                  code: -32602,
-                  data: %{"blockNumber" => "0x1", "hash" => "0x0"},
-                  message: ^expected_message
-                }
-              ]} =
+      assert {:ok,
+              %FetchedBalances{
+                errors: [
+                  %{
+                    code: -32602,
+                    data: %{hash_data: "0x0", block_quantity: "0x1"},
+                    message: ^expected_message
+                  }
+                ],
+                params_list: []
+              }} =
                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}", %{
+    test "with a mix of valid and invalid hash_data returns both", %{
       json_rpc_named_arguments: json_rpc_named_arguments
     } do
       if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
@@ -128,7 +133,7 @@ defmodule EthereumJSONRPCTest do
         end)
       end
 
-      assert {:error, reasons} =
+      assert {:ok, %FetchedBalances{params_list: params_list, errors: errors}} =
                EthereumJSONRPC.fetch_balances(
                  [
                    # start with :ok
@@ -160,8 +165,11 @@ defmodule EthereumJSONRPCTest do
                  json_rpc_named_arguments
                )
 
-      assert is_list(reasons)
-      assert length(reasons) > 1
+      assert is_list(params_list)
+      assert length(params_list) > 1
+
+      assert is_list(errors)
+      assert length(errors) > 1
     end
   end
 
@@ -173,7 +181,8 @@ defmodule EthereumJSONRPCTest do
           {:ok, []}
         end)
 
-        assert EthereumJSONRPC.fetch_beneficiaries(1..1, json_rpc_named_arguments) == {:ok, MapSet.new()}
+        assert EthereumJSONRPC.fetch_beneficiaries(1..1, json_rpc_named_arguments) ==
+                 {:ok, %FetchedBeneficiaries{params_set: MapSet.new(), errors: []}}
       end
     end
   end
@@ -196,12 +205,13 @@ defmodule EthereumJSONRPCTest do
         end
 
       if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
-        expect(EthereumJSONRPC.Mox, :json_rpc, fn _json, _options ->
+        expect(EthereumJSONRPC.Mox, :json_rpc, fn [%{id: id}], _options ->
           block_number = "0x0"
 
           {:ok,
            [
              %{
+               id: id,
                result: %{
                  "difficulty" => "0x0",
                  "gasLimit" => "0x0",
@@ -244,7 +254,7 @@ defmodule EthereumJSONRPCTest do
         end)
       end
 
-      assert {:ok, %{blocks: [_ | _], transactions: [_ | _]}} =
+      assert {:ok, %Blocks{blocks_params: [_ | _], transactions_params: [_ | _]}} =
                EthereumJSONRPC.fetch_blocks_by_hash([block_hash], json_rpc_named_arguments)
     end
 
@@ -265,8 +275,18 @@ defmodule EthereumJSONRPCTest do
         end)
       end
 
-      assert {:error, [%{data: %{hash: "0x0"}}]} =
-               EthereumJSONRPC.fetch_blocks_by_hash(["0x0"], json_rpc_named_arguments)
+      hash = "0x0"
+
+      assert {:ok,
+              %Blocks{
+                errors: [
+                  %{
+                    data: %{
+                      hash: ^hash
+                    }
+                  }
+                ]
+              }} = EthereumJSONRPC.fetch_blocks_by_hash([hash], json_rpc_named_arguments)
     end
 
     test "full batch errors are returned", %{json_rpc_named_arguments: json_rpc_named_arguments} do
@@ -309,15 +329,29 @@ defmodule EthereumJSONRPCTest do
         end)
       end
 
-      assert {:error,
-              [%{data: %{number: 1_000_000_000_000_000_000_001}}, %{data: %{number: 1_000_000_000_000_000_000_000}}]} =
+      assert {:ok,
+              %EthereumJSONRPC.Blocks{
+                block_second_degree_relations_params: [],
+                blocks_params: [],
+                errors: [
+                  %{
+                    data: %{number: 1_000_000_000_000_000_000_001}
+                  },
+                  %{
+                    data: %{number: 1_000_000_000_000_000_000_000}
+                  }
+                ],
+                transactions_params: []
+              }} =
                EthereumJSONRPC.fetch_blocks_by_range(
                  1_000_000_000_000_000_000_000..1_000_000_000_000_000_000_001,
                  json_rpc_named_arguments
                )
     end
 
-    test "returns only errors if a mix of results and errors", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+    test "returns only errors and results if a mix of results and errors", %{
+      json_rpc_named_arguments: json_rpc_named_arguments
+    } do
       # Can't be faked reliably on real chain
       moxed_json_rpc_named_arguments = Keyword.put(json_rpc_named_arguments, :transport, EthereumJSONRPC.Mox)
 
@@ -336,30 +370,71 @@ defmodule EthereumJSONRPCTest do
              id: 1,
              result: %{
                "difficulty" => "0x0",
+               "extraData" => "0x",
                "gasLimit" => "0x0",
                "gasUsed" => "0x0",
                "hash" => "0x0",
+               "logsBloom" => "0x",
                "miner" => "0x0",
                "number" => "0x0",
                "parentHash" => "0x0",
+               "receiptsRoot" => "0x0",
+               "sha3Uncles" => "0x0",
                "size" => "0x0",
+               "stateRoot" => "0x0",
                "timestamp" => "0x0",
                "totalDifficulty" => "0x0",
-               "transactions" => []
+               "transactions" => [],
+               "transactionsRoot" => [],
+               "uncles" => []
              },
              jsonrpc: "2.0"
            }
          ]}
       end)
 
-      assert {:error, [%{data: %{number: 1_000_000_000_000_000_000_000}}]} =
+      assert {:ok,
+              %EthereumJSONRPC.Blocks{
+                block_second_degree_relations_params: [],
+                blocks_params: [
+                  %{
+                    difficulty: 0,
+                    extra_data: "0x",
+                    gas_limit: 0,
+                    gas_used: 0,
+                    hash: "0x0",
+                    logs_bloom: "0x",
+                    miner_hash: "0x0",
+                    mix_hash: "0x0",
+                    nonce: 0,
+                    number: 0,
+                    parent_hash: "0x0",
+                    receipts_root: "0x0",
+                    sha3_uncles: "0x0",
+                    size: 0,
+                    state_root: "0x0",
+                    timestamp: _,
+                    total_difficulty: 0,
+                    transactions_root: [],
+                    uncles: []
+                  }
+                ],
+                errors: [
+                  %{
+                    code: -32602,
+                    data: %{number: 1_000_000_000_000_000_000_000},
+                    message: "Invalid params: Invalid block number: number too large to fit in target type."
+                  }
+                ],
+                transactions_params: []
+              }} =
                EthereumJSONRPC.fetch_blocks_by_range(
                  1_000_000_000_000_000_000_000..1_000_000_000_000_000_000_001,
                  moxed_json_rpc_named_arguments
                )
     end
 
-    test "nil result indicated end-of-chain", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+    test "nil result indicated error code 404", %{json_rpc_named_arguments: json_rpc_named_arguments} do
       # Can't be faked reliably on real chain
       moxed_json_rpc_named_arguments = Keyword.put(json_rpc_named_arguments, :transport, EthereumJSONRPC.Mox)
 
@@ -398,8 +473,13 @@ defmodule EthereumJSONRPCTest do
          ]}
       end)
 
-      assert {:ok, :end_of_chain, %{blocks: [_], transactions: []}} =
-               EthereumJSONRPC.fetch_blocks_by_range(0..1, moxed_json_rpc_named_arguments)
+      assert {:ok,
+              %EthereumJSONRPC.Blocks{
+                block_second_degree_relations_params: [],
+                blocks_params: [%{}],
+                errors: [%{code: 404, data: %{number: 1}, message: "Not Found"}],
+                transactions_params: []
+              }} = EthereumJSONRPC.fetch_blocks_by_range(0..1, moxed_json_rpc_named_arguments)
     end
   end
 

apps/indexer/lib/indexer/block/catchup/fetcher.ex

@@ -166,9 +166,11 @@ defmodule Indexer.Block.Catchup.Fetcher do
          sequence
        ) do
     case fetch_and_import_range(block_fetcher, range) do
-      {:ok, {inserted, next}} ->
-        cap_seq(sequence, next, range)
-        {:ok, inserted}
+      {:ok, %{inserted: inserted, errors: errors}} ->
+        errors = cap_seq(sequence, errors, range)
+        retry(sequence, errors)
+
+        {:ok, inserted: inserted}
 
       {:error, {step, reason}} = error ->
         Logger.error(fn ->
@@ -200,19 +202,27 @@ defmodule Indexer.Block.Catchup.Fetcher do
     end
   end
 
-  defp cap_seq(seq, next, range) do
-    case next do
-      :more ->
+  defp cap_seq(seq, errors, range) do
+    {not_founds, other_errors} =
+      Enum.split_with(errors, fn
+        %{code: 404, data: %{number: _}} -> true
+        _ -> false
+      end)
+
+    case not_founds do
+      [] ->
         Logger.debug(fn ->
           first_block_number..last_block_number = range
           "got blocks #{first_block_number} - #{last_block_number}"
         end)
 
-      :end_of_chain ->
+        other_errors
+
+      _ ->
         Sequence.cap(seq)
     end
 
-    :ok
+    other_errors
   end
 
   defp push_back(sequence, range) do
@@ -222,6 +232,41 @@ defmodule Indexer.Block.Catchup.Fetcher do
     end
   end
 
+  defp retry(sequence, errors) when is_list(errors) do
+    errors
+    |> errors_to_ranges()
+    |> Enum.map(&push_back(sequence, &1))
+  end
+
+  defp errors_to_ranges(errors) when is_list(errors) do
+    errors
+    |> Enum.flat_map(&error_to_numbers/1)
+    |> numbers_to_ranges()
+  end
+
+  defp error_to_numbers(%{data: %{number: number}}) when is_integer(number), do: [number]
+
+  defp numbers_to_ranges([]), do: []
+
+  defp numbers_to_ranges(numbers) when is_list(numbers) do
+    numbers
+    |> Enum.sort()
+    |> Enum.chunk_while(
+      nil,
+      fn
+        number, nil ->
+          {:cont, number..number}
+
+        number, first..last when number == last + 1 ->
+          {:cont, first..number}
+
+        number, range ->
+          {:cont, range, number..number}
+      end,
+      fn range -> {:cont, range} end
+    )
+  end
+
   defp put_memory_monitor(sequence_options, %__MODULE__{memory_monitor: nil}) when is_list(sequence_options),
     do: sequence_options
 

apps/indexer/lib/indexer/block/fetcher.ex

@@ -5,6 +5,7 @@ defmodule Indexer.Block.Fetcher do
 
   require Logger
 
+  alias EthereumJSONRPC.{Blocks, FetchedBeneficiaries}
   alias Explorer.Chain.{Address, Block, Import}
   alias Indexer.{AddressExtraction, CoinBalance, MintTransfer, Token, TokenTransfers}
   alias Indexer.Address.{CoinBalances, TokenBalances}
@@ -76,7 +77,7 @@ defmodule Indexer.Block.Fetcher do
   end
 
   @spec fetch_and_import_range(t, Range.t()) ::
-          {:ok, {inserted :: %{}, next :: :more | :end_of_chain}}
+          {:ok, %{inserted: %{}, errors: [EthereumJSONRPC.Transport.error()]}}
           | {:error,
              {step :: atom(), reason :: term()}
              | [%Ecto.Changeset{}]
@@ -90,23 +91,26 @@ defmodule Indexer.Block.Fetcher do
         _.._ = range
       )
       when callback_module != nil do
-    with {:blocks, {:ok, next, result}} <-
-           {:blocks, EthereumJSONRPC.fetch_blocks_by_range(range, json_rpc_named_arguments)},
-         %{
-           blocks: blocks,
-           transactions: transactions_without_receipts,
-           block_second_degree_relations: block_second_degree_relations
-         } = result,
-         blocks = Transform.transform_blocks(blocks),
-         {:receipts, {:ok, receipt_params}} <- {:receipts, Receipts.fetch(state, transactions_without_receipts)},
+    with {:blocks,
+          {:ok,
+           %Blocks{
+             blocks_params: blocks_params,
+             transactions_params: transactions_params_without_receipts,
+             block_second_degree_relations_params: block_second_degree_relations_params,
+             errors: blocks_errors
+           }}} <- {:blocks, EthereumJSONRPC.fetch_blocks_by_range(range, json_rpc_named_arguments)},
+         blocks = Transform.transform_blocks(blocks_params),
+         {:receipts, {:ok, receipt_params}} <- {:receipts, Receipts.fetch(state, transactions_params_without_receipts)},
          %{logs: logs, receipts: receipts} = receipt_params,
-         transactions_with_receipts = Receipts.put(transactions_without_receipts, receipts),
+         transactions_with_receipts = Receipts.put(transactions_params_without_receipts, receipts),
          %{token_transfers: token_transfers, tokens: tokens} = TokenTransfers.parse(logs),
          %{mint_transfers: mint_transfers} = MintTransfer.parse(logs),
-         {:beneficiaries, {:ok, beneficiaries}} <- fetch_beneficiaries(range, json_rpc_named_arguments),
+         {:beneficiaries,
+          {:ok, %FetchedBeneficiaries{params_set: beneficiary_params_set, errors: beneficiaries_errors}}} <-
+           fetch_beneficiaries(range, json_rpc_named_arguments),
          addresses =
            AddressExtraction.extract_addresses(%{
-             block_reward_contract_beneficiaries: MapSet.to_list(beneficiaries),
+             block_reward_contract_beneficiaries: MapSet.to_list(beneficiary_params_set),
              blocks: blocks,
              logs: logs,
              mint_transfers: mint_transfers,
@@ -120,7 +124,7 @@ defmodule Indexer.Block.Fetcher do
              transactions_params: transactions_with_receipts
            }
            |> CoinBalances.params_set()
-           |> MapSet.union(beneficiaries),
+           |> MapSet.union(beneficiary_params_set),
          address_token_balances = TokenBalances.params_set(%{token_transfers_params: token_transfers}),
          {:ok, inserted} <-
            __MODULE__.import(
@@ -130,14 +134,14 @@ defmodule Indexer.Block.Fetcher do
                address_coin_balances: %{params: coin_balances_params_set},
                address_token_balances: %{params: address_token_balances},
                blocks: %{params: blocks},
-               block_second_degree_relations: %{params: block_second_degree_relations},
+               block_second_degree_relations: %{params: block_second_degree_relations_params},
                logs: %{params: logs},
                token_transfers: %{params: token_transfers},
                tokens: %{on_conflict: :nothing, params: tokens},
                transactions: %{params: transactions_with_receipts}
              }
            ) do
-      {:ok, {inserted, next}}
+      {:ok, %{inserted: inserted, errors: blocks_errors ++ beneficiaries_errors}}
     else
       {step, {:error, reason}} -> {:error, {step, reason}}
       {:error, :timeout} = error -> error
@@ -200,9 +204,8 @@ defmodule Indexer.Block.Fetcher do
 
   defp fetch_beneficiaries(range, json_rpc_named_arguments) do
     result =
-      case EthereumJSONRPC.fetch_beneficiaries(range, json_rpc_named_arguments) do
-        :ignore -> {:ok, MapSet.new()}
-        result -> result
+      with :ignore <- EthereumJSONRPC.fetch_beneficiaries(range, json_rpc_named_arguments) do
+        {:ok, %FetchedBeneficiaries{params_set: MapSet.new()}}
       end
 
     {:beneficiaries, result}

apps/indexer/lib/indexer/block/realtime/fetcher.ex

@@ -11,7 +11,7 @@ defmodule Indexer.Block.Realtime.Fetcher do
   import Indexer.Block.Fetcher, only: [async_import_tokens: 1, async_import_uncles: 1, fetch_and_import_range: 2]
 
   alias Ecto.Changeset
-  alias EthereumJSONRPC.Subscription
+  alias EthereumJSONRPC.{FetchedBalances, Subscription}
   alias Explorer.Chain
   alias Indexer.{AddressExtraction, Block, TokenBalances}
   alias Indexer.Block.Realtime.TaskSupervisor
@@ -127,11 +127,22 @@ defmodule Indexer.Block.Realtime.Fetcher do
 
   def fetch_and_import_block(block_number_to_fetch, block_fetcher, retry \\ 3) do
     case fetch_and_import_range(block_fetcher, block_number_to_fetch..block_number_to_fetch) do
-      {:ok, {_inserted, _next}} ->
+      {:ok, %{inserted: _, errors: []}} ->
         Logger.debug(fn ->
           ["realtime indexer fetched and imported block ", to_string(block_number_to_fetch)]
         end)
 
+      {:ok, %{inserted: _, errors: [_ | _] = errors}} ->
+        Logger.error(fn ->
+          [
+            "realtime indexer failed to fetch block",
+            to_string(block_number_to_fetch),
+            ": ",
+            inspect(errors),
+            ".  Block will be retried by catchup indexer."
+          ]
+        end)
+
       {:error, {step, reason}} ->
         Logger.error(fn ->
           [
@@ -247,20 +258,27 @@ defmodule Indexer.Block.Realtime.Fetcher do
          %Block.Fetcher{json_rpc_named_arguments: json_rpc_named_arguments},
          %{addresses_params: addresses_params} = options
        ) do
-    with {:ok, fetched_balances_params} <-
-           options
-           |> fetch_balances_params_list()
-           |> EthereumJSONRPC.fetch_balances(json_rpc_named_arguments) do
-      merged_addresses_params =
-        %{address_coin_balances: fetched_balances_params}
-        |> AddressExtraction.extract_addresses()
-        |> Kernel.++(addresses_params)
-        |> AddressExtraction.merge_addresses()
-
-      value_fetched_at = DateTime.utc_now()
-      importable_balances_params = Enum.map(fetched_balances_params, &Map.put(&1, :value_fetched_at, value_fetched_at))
-
-      {:ok, %{addresses_params: merged_addresses_params, balances_params: importable_balances_params}}
+    case options
+         |> fetch_balances_params_list()
+         |> EthereumJSONRPC.fetch_balances(json_rpc_named_arguments) do
+      {:ok, %FetchedBalances{params_list: params_list, errors: []}} ->
+        merged_addresses_params =
+          %{address_coin_balances: params_list}
+          |> AddressExtraction.extract_addresses()
+          |> Kernel.++(addresses_params)
+          |> AddressExtraction.merge_addresses()
+
+        value_fetched_at = DateTime.utc_now()
+
+        importable_balances_params = Enum.map(params_list, &Map.put(&1, :value_fetched_at, value_fetched_at))
+
+        {:ok, %{addresses_params: merged_addresses_params, balances_params: importable_balances_params}}
+
+      {:error, _} = error ->
+        error
+
+      {:ok, %FetchedBalances{errors: errors}} ->
+        {:error, errors}
     end
   end
 

apps/indexer/lib/indexer/block/uncle/fetcher.ex

@@ -6,6 +6,7 @@ defmodule Indexer.Block.Uncle.Fetcher do
 
   require Logger
 
+  alias EthereumJSONRPC.Blocks
   alias Explorer.Chain
   alias Explorer.Chain.Hash
   alias Indexer.{AddressExtraction, Block, BufferedTask}
@@ -72,38 +73,8 @@ defmodule Indexer.Block.Uncle.Fetcher do
     Logger.debug(fn -> "fetching #{length(unique_hashes)} uncle blocks" end)
 
     case EthereumJSONRPC.fetch_blocks_by_hash(unique_hashes, json_rpc_named_arguments) do
-      {:ok,
-       %{
-         blocks: blocks_params,
-         transactions: transactions_params,
-         block_second_degree_relations: block_second_degree_relations_params
-       }} ->
-        addresses_params =
-          AddressExtraction.extract_addresses(%{blocks: blocks_params, transactions: transactions_params})
-
-        case Block.Fetcher.import(block_fetcher, %{
-               addresses: %{params: addresses_params},
-               blocks: %{params: blocks_params},
-               block_second_degree_relations: %{params: block_second_degree_relations_params},
-               transactions: %{params: transactions_params, on_conflict: :nothing}
-             }) do
-          {:ok, _} ->
-            :ok
-
-          {:error, step, failed_value, _changes_so_far} ->
-            Logger.error(fn ->
-              [
-                "failed to import ",
-                unique_hashes |> length() |> to_string(),
-                "uncle blocks in step ",
-                inspect(step),
-                ": ",
-                inspect(failed_value)
-              ]
-            end)
-
-            {:retry, unique_hashes}
-        end
+      {:ok, blocks} ->
+        run_blocks(blocks, block_fetcher, unique_hashes)
 
       {:error, reason} ->
         Logger.error(fn ->
@@ -114,6 +85,45 @@ defmodule Indexer.Block.Uncle.Fetcher do
     end
   end
 
+  defp run_blocks(%Blocks{blocks_params: []}, _, original_entries), do: {:retry, original_entries}
+
+  defp run_blocks(
+         %Blocks{
+           blocks_params: blocks_params,
+           transactions_params: transactions_params,
+           block_second_degree_relations_params: block_second_degree_relations_params,
+           errors: errors
+         },
+         block_fetcher,
+         original_entries
+       ) do
+    addresses_params = AddressExtraction.extract_addresses(%{blocks: blocks_params, transactions: transactions_params})
+
+    case Block.Fetcher.import(block_fetcher, %{
+           addresses: %{params: addresses_params},
+           blocks: %{params: blocks_params},
+           block_second_degree_relations: %{params: block_second_degree_relations_params},
+           transactions: %{params: transactions_params, on_conflict: :nothing}
+         }) do
+      {:ok, _} ->
+        retry(errors, original_entries)
+
+      {:error, step, failed_value, _changes_so_far} ->
+        Logger.error(fn ->
+          [
+            "failed to import ",
+            original_entries |> length() |> to_string(),
+            "uncle blocks in step ",
+            inspect(step),
+            ": ",
+            inspect(failed_value)
+          ]
+        end)
+
+        {:retry, original_entries}
+    end
+  end
+
   @ignored_options ~w(address_hash_to_fetched_balance_block_number transaction_hash_to_block_number)a
 
   @impl Block.Fetcher
@@ -170,4 +180,42 @@ defmodule Indexer.Block.Uncle.Fetcher do
       %{uncle_hash: uncle_hash, index: index, hash: hash}
     end)
   end
+
+  defp retry([], _), do: :ok
+
+  defp retry(errors, original_entries) when is_list(errors) do
+    retried_entries = errors_to_entries(errors)
+
+    Logger.error(fn ->
+      [
+        "failed to fetch ",
+        retried_entries |> length() |> to_string(),
+        "/",
+        original_entries |> length() |> to_string(),
+        " uncles: ",
+        errors_to_iodata(errors)
+      ]
+    end)
+  end
+
+  defp errors_to_entries(errors) when is_list(errors) do
+    Enum.map(errors, &error_to_entry/1)
+  end
+
+  defp error_to_entry(%{data: %{hash: hash}}) when is_binary(hash), do: hash
+
+  defp errors_to_iodata(errors) when is_list(errors) do
+    errors_to_iodata(errors, [])
+  end
+
+  defp errors_to_iodata([], iodata), do: iodata
+
+  defp errors_to_iodata([error | errors], iodata) do
+    errors_to_iodata(errors, [iodata | error_to_iodata(error)])
+  end
+
+  defp error_to_iodata(%{code: code, message: message, data: %{hash: hash}})
+       when is_integer(code) and is_binary(message) and is_binary(hash) do
+    [hash, ": (", to_string(code), ") ", message, ?\n]
+  end
 end

apps/indexer/lib/indexer/coin_balance/fetcher.ex

@@ -6,8 +6,9 @@ defmodule Indexer.CoinBalance.Fetcher do
 
   require Logger
 
-  import EthereumJSONRPC, only: [integer_to_quantity: 1]
+  import EthereumJSONRPC, only: [integer_to_quantity: 1, quantity_to_integer: 1]
 
+  alias EthereumJSONRPC.FetchedBalances
   alias Explorer.Chain
   alias Explorer.Chain.{Block, Hash}
   alias Indexer.BufferedTask
@@ -75,23 +76,14 @@ defmodule Indexer.CoinBalance.Fetcher do
     |> Enum.map(&entry_to_params/1)
     |> EthereumJSONRPC.fetch_balances(json_rpc_named_arguments)
     |> case do
-      {:ok, balances_params} ->
-        value_fetched_at = DateTime.utc_now()
-
-        importable_balances_params = Enum.map(balances_params, &Map.put(&1, :value_fetched_at, value_fetched_at))
-
-        addresses_params = balances_params_to_address_params(importable_balances_params)
-
-        {:ok, _} =
-          Chain.import(%{
-            addresses: %{params: addresses_params, with: :balance_changeset},
-            address_coin_balances: %{params: importable_balances_params}
-          })
-
-        :ok
+      {:ok, fetched_balances} ->
+        run_fetched_balances(fetched_balances, unique_entries)
 
       {:error, reason} ->
-        Logger.debug(fn -> "failed to fetch #{length(unique_entries)} balances, #{inspect(reason)}" end)
+        Logger.error(fn ->
+          ["failed to fetch ", unique_entries |> length() |> to_string(), " balances, ", inspect(reason)]
+        end)
+
         {:retry, unique_entries}
     end
   end
@@ -116,4 +108,71 @@ defmodule Indexer.CoinBalance.Fetcher do
       %{hash: address_hash, fetched_coin_balance_block_number: block_number, fetched_coin_balance: value}
     end)
   end
+
+  defp run_fetched_balances(%FetchedBalances{params_list: []}, original_entries), do: {:retry, original_entries}
+
+  defp run_fetched_balances(%FetchedBalances{params_list: params_list, errors: errors}, original_entries) do
+    value_fetched_at = DateTime.utc_now()
+
+    importable_balances_params = Enum.map(params_list, &Map.put(&1, :value_fetched_at, value_fetched_at))
+
+    addresses_params = balances_params_to_address_params(importable_balances_params)
+
+    {:ok, _} =
+      Chain.import(%{
+        addresses: %{params: addresses_params, with: :balance_changeset},
+        address_coin_balances: %{params: importable_balances_params}
+      })
+
+    retry(errors, original_entries)
+  end
+
+  defp retry([], _), do: :ok
+
+  defp retry(errors, original_entries) when is_list(errors) do
+    retried_entries = fetched_balances_errors_to_entries(errors)
+
+    Logger.error(fn ->
+      [
+        "failed to fetch ",
+        retried_entries |> length() |> to_string(),
+        "/",
+        original_entries |> length() |> to_string(),
+        " balances: ",
+        fetched_balance_errors_to_iodata(errors)
+      ]
+    end)
+
+    {:retry, retried_entries}
+  end
+
+  defp fetched_balances_errors_to_entries(errors) when is_list(errors) do
+    Enum.map(errors, &fetched_balance_error_to_entry/1)
+  end
+
+  defp fetched_balance_error_to_entry(%{data: %{block_quantity: block_quantity, hash_data: hash_data}})
+       when is_binary(block_quantity) and is_binary(hash_data) do
+    {:ok, %Hash{bytes: address_hash_bytes}} = Hash.Address.cast(hash_data)
+    block_number = quantity_to_integer(block_quantity)
+    {address_hash_bytes, block_number}
+  end
+
+  defp fetched_balance_errors_to_iodata(errors) when is_list(errors) do
+    fetched_balance_errors_to_iodata(errors, [])
+  end
+
+  defp fetched_balance_errors_to_iodata([], iodata), do: iodata
+
+  defp fetched_balance_errors_to_iodata([error | errors], iodata) do
+    fetched_balance_errors_to_iodata(errors, [iodata | fetched_balance_error_to_iodata(error)])
+  end
+
+  defp fetched_balance_error_to_iodata(%{
+         code: code,
+         message: message,
+         data: %{block_quantity: block_quantity, hash_data: hash_data}
+       })
+       when is_integer(code) and is_binary(message) and is_binary(block_quantity) and is_binary(hash_data) do
+    [hash_data, "@", quantity_to_integer(block_quantity), ": (", to_string(code), ") ", message, ?\n]
+  end
 end

apps/indexer/test/indexer/block/catchup/bound_interval_supervisor_test.exs

@@ -22,6 +22,8 @@ defmodule Indexer.Block.Catchup.BoundIntervalSupervisorTest do
     # See https://github.com/poanetwork/blockscout/issues/597
     @tag :no_geth
     test "starts fetching blocks from latest and goes down", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+      Logger.configure(truncate: :infinity)
+
       if json_rpc_named_arguments[:transport] == EthereumJSONRPC.Mox do
         case Keyword.fetch!(json_rpc_named_arguments, :variant) do
           EthereumJSONRPC.Parity ->
@@ -63,8 +65,8 @@ defmodule Indexer.Block.Catchup.BoundIntervalSupervisorTest do
                    "uncles" => []
                  }}
 
-              %{method: "trace_block"}, _options ->
-                {:ok, []}
+              [%{method: "trace_block"} | _] = requests, _options ->
+                {:ok, Enum.map(requests, fn %{id: id} -> %{id: id, result: []} end)}
 
               [%{method: "eth_getBlockByNumber", params: [_, true]} | _] = requests, _options ->
                 {:ok,
@@ -476,8 +478,8 @@ defmodule Indexer.Block.Catchup.BoundIntervalSupervisorTest do
       |> (fn mock ->
             case Keyword.fetch!(json_rpc_named_arguments, :variant) do
               EthereumJSONRPC.Parity ->
-                expect(mock, :json_rpc, fn %{method: "trace_block"}, _options ->
-                  {:ok, []}
+                expect(mock, :json_rpc, fn [%{method: "trace_block"} | _] = requests, _options ->
+                  {:ok, Enum.map(requests, fn %{id: id} -> %{id: id, result: []} end)}
                 end)
 
               _ ->

apps/indexer/test/indexer/block/fetcher_test.exs

@@ -109,8 +109,8 @@ defmodule Indexer.Block.FetcherTest do
                  }
                ]}
             end)
-            |> expect(:json_rpc, fn %{id: _id, method: "trace_block", params: [^block_quantity]}, _options ->
-              {:ok, []}
+            |> expect(:json_rpc, fn [%{id: id, method: "trace_block", params: [^block_quantity]}], _options ->
+              {:ok, [%{id: id, result: []}]}
             end)
             |> expect(:json_rpc, fn [
                                       %{
@@ -214,10 +214,13 @@ defmodule Indexer.Block.FetcherTest do
         fn -> Fetcher.fetch_and_import_range(block_fetcher, block_number..block_number) end,
         fn result ->
           assert {:ok,
-                  {%{
-                     addresses: [%Address{hash: ^address_hash}],
-                     blocks: [%Chain.Block{hash: ^block_hash}]
-                   }, :more}} = result
+                  %{
+                    inserted: %{
+                      addresses: [%Address{hash: ^address_hash}],
+                      blocks: [%Chain.Block{hash: ^block_hash}]
+                    },
+                    errors: []
+                  }} = result
 
           wait_for_tasks(InternalTransaction.Fetcher)
           wait_for_tasks(CoinBalance.Fetcher)
@@ -359,9 +362,8 @@ defmodule Indexer.Block.FetcherTest do
                  }
                ]}
             end)
-            |> expect(:json_rpc, fn json, _options ->
-              assert %{id: _id, method: "trace_block", params: [^block_quantity]} = json
-              {:ok, []}
+            |> expect(:json_rpc, fn [%{id: id, method: "trace_block", params: [^block_quantity]}], _options ->
+              {:ok, [%{id: id, result: []}]}
             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
@@ -507,57 +509,60 @@ defmodule Indexer.Block.FetcherTest do
 
         EthereumJSONRPC.Parity ->
           assert {:ok,
-                  {%{
-                     addresses: [
-                       %Address{
-                         hash:
-                           %Explorer.Chain.Hash{
-                             byte_count: 20,
-                             bytes:
-                               <<139, 243, 141, 71, 100, 146, 144, 100, 242, 212, 211, 165, 101, 32, 167, 106, 179, 223,
-                                 65, 91>>
-                           } = first_address_hash
-                       },
-                       %Address{
-                         hash:
-                           %Explorer.Chain.Hash{
-                             byte_count: 20,
-                             bytes:
-                               <<232, 221, 197, 199, 162, 210, 240, 215, 169, 121, 132, 89, 192, 16, 79, 223, 94, 152,
-                                 122, 202>>
-                           } = second_address_hash
-                       }
-                     ],
-                     blocks: [
-                       %Chain.Block{
-                         hash: %Explorer.Chain.Hash{
-                           byte_count: 32,
-                           bytes:
-                             <<246, 180, 184, 200, 141, 243, 235, 210, 82, 236, 71, 99, 40, 51, 77, 192, 38, 207, 102,
-                               96, 106, 132, 251, 118, 155, 61, 60, 188, 204, 132, 113, 189>>
-                         }
-                       }
-                     ],
-                     logs: [
-                       %Log{
-                         index: 0,
-                         transaction_hash: %Explorer.Chain.Hash{
-                           byte_count: 32,
-                           bytes:
-                             <<83, 189, 136, 72, 114, 222, 62, 72, 134, 146, 136, 27, 174, 236, 38, 46, 123, 149, 35,
-                               77, 57, 101, 36, 140, 57, 254, 153, 47, 255, 212, 51, 229>>
-                         }
-                       }
-                     ],
-                     transactions: [
-                       %Explorer.Chain.Hash{
-                         byte_count: 32,
-                         bytes:
-                           <<83, 189, 136, 72, 114, 222, 62, 72, 134, 146, 136, 27, 174, 236, 38, 46, 123, 149, 35, 77,
-                             57, 101, 36, 140, 57, 254, 153, 47, 255, 212, 51, 229>>
-                       }
-                     ]
-                   }, :more}} = Fetcher.fetch_and_import_range(block_fetcher, block_number..block_number)
+                  %{
+                    inserted: %{
+                      addresses: [
+                        %Address{
+                          hash:
+                            %Explorer.Chain.Hash{
+                              byte_count: 20,
+                              bytes:
+                                <<139, 243, 141, 71, 100, 146, 144, 100, 242, 212, 211, 165, 101, 32, 167, 106, 179,
+                                  223, 65, 91>>
+                            } = first_address_hash
+                        },
+                        %Address{
+                          hash:
+                            %Explorer.Chain.Hash{
+                              byte_count: 20,
+                              bytes:
+                                <<232, 221, 197, 199, 162, 210, 240, 215, 169, 121, 132, 89, 192, 16, 79, 223, 94, 152,
+                                  122, 202>>
+                            } = second_address_hash
+                        }
+                      ],
+                      blocks: [
+                        %Chain.Block{
+                          hash: %Explorer.Chain.Hash{
+                            byte_count: 32,
+                            bytes:
+                              <<246, 180, 184, 200, 141, 243, 235, 210, 82, 236, 71, 99, 40, 51, 77, 192, 38, 207, 102,
+                                96, 106, 132, 251, 118, 155, 61, 60, 188, 204, 132, 113, 189>>
+                          }
+                        }
+                      ],
+                      logs: [
+                        %Log{
+                          index: 0,
+                          transaction_hash: %Explorer.Chain.Hash{
+                            byte_count: 32,
+                            bytes:
+                              <<83, 189, 136, 72, 114, 222, 62, 72, 134, 146, 136, 27, 174, 236, 38, 46, 123, 149, 35,
+                                77, 57, 101, 36, 140, 57, 254, 153, 47, 255, 212, 51, 229>>
+                          }
+                        }
+                      ],
+                      transactions: [
+                        %Explorer.Chain.Hash{
+                          byte_count: 32,
+                          bytes:
+                            <<83, 189, 136, 72, 114, 222, 62, 72, 134, 146, 136, 27, 174, 236, 38, 46, 123, 149, 35, 77,
+                              57, 101, 36, 140, 57, 254, 153, 47, 255, 212, 51, 229>>
+                        }
+                      ]
+                    },
+                    errors: []
+                  }} = Fetcher.fetch_and_import_range(block_fetcher, block_number..block_number)
 
           wait_for_tasks(InternalTransaction.Fetcher)
           wait_for_tasks(CoinBalance.Fetcher)

apps/indexer/test/indexer/block/realtime/fetcher_test.exs

@@ -198,8 +198,9 @@ defmodule Indexer.Block.Realtime.FetcherTest do
              }
            ]}
         end)
-        |> expect(:json_rpc, 2, fn %{method: "trace_block"}, _options ->
-          {:ok, []}
+        |> expect(:json_rpc, fn [%{method: "trace_block"}, %{method: "trace_block"}] = requests, _options ->
+          responses = Enum.map(requests, fn %{id: id} -> %{id: id, result: []} end)
+          {:ok, responses}
         end)
         |> expect(:json_rpc, fn [
                                   %{
@@ -369,47 +370,50 @@ defmodule Indexer.Block.Realtime.FetcherTest do
       end
 
       assert {:ok,
-              {%{
-                 addresses: [
-                   %Address{hash: first_address_hash, fetched_coin_balance_block_number: 3_946_079},
-                   %Address{hash: second_address_hash, fetched_coin_balance_block_number: 3_946_079},
-                   %Address{hash: third_address_hash, fetched_coin_balance_block_number: 3_946_079},
-                   %Address{hash: fourth_address_hash, fetched_coin_balance_block_number: 3_946_080},
-                   %Address{hash: fifth_address_hash, fetched_coin_balance_block_number: 3_946_079}
-                 ],
-                 address_coin_balances: [
-                   %{
-                     address_hash: first_address_hash,
-                     block_number: 3_946_079
-                   },
-                   %{
-                     address_hash: second_address_hash,
-                     block_number: 3_946_079
-                   },
-                   %{
-                     address_hash: third_address_hash,
-                     block_number: 3_946_079
-                   },
-                   %{
-                     address_hash: fourth_address_hash,
-                     block_number: 3_946_080
-                   },
-                   %{
-                     address_hash: fifth_address_hash,
-                     block_number: 3_946_079
-                   }
-                 ],
-                 blocks: [%Chain.Block{number: 3_946_079}, %Chain.Block{number: 3_946_080}],
-                 internal_transactions: [
-                   %{index: 0, transaction_hash: transaction_hash},
-                   %{index: 1, transaction_hash: transaction_hash},
-                   %{index: 2, transaction_hash: transaction_hash},
-                   %{index: 3, transaction_hash: transaction_hash},
-                   %{index: 4, transaction_hash: transaction_hash},
-                   %{index: 5, transaction_hash: transaction_hash}
-                 ],
-                 transactions: [transaction_hash]
-               }, :more}} = Indexer.Block.Fetcher.fetch_and_import_range(block_fetcher, 3_946_079..3_946_080)
+              %{
+                inserted: %{
+                  addresses: [
+                    %Address{hash: first_address_hash, fetched_coin_balance_block_number: 3_946_079},
+                    %Address{hash: second_address_hash, fetched_coin_balance_block_number: 3_946_079},
+                    %Address{hash: third_address_hash, fetched_coin_balance_block_number: 3_946_079},
+                    %Address{hash: fourth_address_hash, fetched_coin_balance_block_number: 3_946_080},
+                    %Address{hash: fifth_address_hash, fetched_coin_balance_block_number: 3_946_079}
+                  ],
+                  address_coin_balances: [
+                    %{
+                      address_hash: first_address_hash,
+                      block_number: 3_946_079
+                    },
+                    %{
+                      address_hash: second_address_hash,
+                      block_number: 3_946_079
+                    },
+                    %{
+                      address_hash: third_address_hash,
+                      block_number: 3_946_079
+                    },
+                    %{
+                      address_hash: fourth_address_hash,
+                      block_number: 3_946_080
+                    },
+                    %{
+                      address_hash: fifth_address_hash,
+                      block_number: 3_946_079
+                    }
+                  ],
+                  blocks: [%Chain.Block{number: 3_946_079}, %Chain.Block{number: 3_946_080}],
+                  internal_transactions: [
+                    %{index: 0, transaction_hash: transaction_hash},
+                    %{index: 1, transaction_hash: transaction_hash},
+                    %{index: 2, transaction_hash: transaction_hash},
+                    %{index: 3, transaction_hash: transaction_hash},
+                    %{index: 4, transaction_hash: transaction_hash},
+                    %{index: 5, transaction_hash: transaction_hash}
+                  ],
+                  transactions: [transaction_hash]
+                },
+                errors: []
+              }} = Indexer.Block.Fetcher.fetch_and_import_range(block_fetcher, 3_946_079..3_946_080)
     end
   end
 end

apps/indexer/test/indexer/block/uncle/fetcher_test.exs

@@ -51,12 +51,13 @@ defmodule Indexer.Block.Uncle.FetcherTest do
       uncle_uncle_hash_data = to_string(block_hash())
 
       EthereumJSONRPC.Mox
-      |> expect(:json_rpc, fn [%{method: "eth_getBlockByHash", params: [^uncle_hash_data, true]}], _ ->
+      |> expect(:json_rpc, fn [%{id: id, method: "eth_getBlockByHash", params: [^uncle_hash_data, true]}], _ ->
         number_quantity = "0x0"
 
         {:ok,
          [
            %{
+             id: id,
              result: %{
                "author" => "0xe2ac1c6843a33f81ae4935e5ef1277a392990381",
                "difficulty" => "0xfffffffffffffffffffffffffffffffe",

apps/indexer/test/indexer/coin_balance/fetcher_test.exs

@@ -289,6 +289,84 @@ defmodule Indexer.CoinBalance.FetcherTest do
     end
   end
 
+  describe "run/2 partial batch" do
+    setup do
+      %{
+        json_rpc_named_arguments: [
+          transport: EthereumJSONRPC.Mox,
+          transport_options: [],
+          # Which one does not matter, so pick one
+          variant: EthereumJSONRPC.Parity
+        ]
+      }
+    end
+
+    test "retries all if no successes", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+      %Hash{bytes: address_hash_bytes} = address_hash()
+      entries = [{address_hash_bytes, block_number()}]
+
+      expect(EthereumJSONRPC.Mox, :json_rpc, fn [%{id: id, method: "eth_getBalance", params: [_, _]}], _ ->
+        {:ok, [%{id: id, error: %{code: 1, message: "Bad"}}]}
+      end)
+
+      assert {:retry, ^entries} = CoinBalance.Fetcher.run(entries, json_rpc_named_arguments)
+    end
+
+    test "retries none if all imported and no fetch errors", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+      %Hash{bytes: address_hash_bytes} = address_hash()
+      entries = [{address_hash_bytes, block_number()}]
+
+      expect(EthereumJSONRPC.Mox, :json_rpc, fn [%{id: id, method: "eth_getBalance", params: [_, _]}], _ ->
+        {:ok, [%{id: id, result: "0x1"}]}
+      end)
+
+      assert :ok = CoinBalance.Fetcher.run(entries, json_rpc_named_arguments)
+    end
+
+    test "retries retries fetch errors if all imported", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+      %Hash{bytes: address_hash_bytes} = address_hash()
+      bad_block_number = block_number()
+      good_block_number = block_number()
+
+      expect(EthereumJSONRPC.Mox, :json_rpc, fn [
+                                                  %{
+                                                    id: first_id,
+                                                    method: "eth_getBalance",
+                                                    params: [_, first_block_quantity]
+                                                  },
+                                                  %{
+                                                    id: second_id,
+                                                    method: "eth_getBalance",
+                                                    params: [_, _]
+                                                  }
+                                                ],
+                                                _ ->
+        responses =
+          case quantity_to_integer(first_block_quantity) do
+            ^good_block_number ->
+              [
+                %{id: first_id, result: "0x1"},
+                %{id: second_id, error: %{code: 2, message: "Bad"}}
+              ]
+
+            ^bad_block_number ->
+              [
+                %{id: first_id, error: %{code: 1, message: "Bad"}},
+                %{id: second_id, result: "0x2"}
+              ]
+          end
+
+        {:ok, responses}
+      end)
+
+      assert {:retry, [{^address_hash_bytes, ^bad_block_number}]} =
+               CoinBalance.Fetcher.run(
+                 [{address_hash_bytes, good_block_number}, {address_hash_bytes, bad_block_number}],
+                 json_rpc_named_arguments
+               )
+    end
+  end
+
   defp wait(producer) do
     producer.()
   rescue