Merge pull request #990 from poanetwork/sa-graphql-api

Add Absinthe for GraphQL API

apps/block_scout_web/lib/block_scout_web/resolvers/block.ex

@@ -0,0 +1,12 @@
+defmodule BlockScoutWeb.Resolvers.Block do
+  @moduledoc false
+
+  alias Explorer.Chain
+
+  def get_by(_, %{number: number}, _) do
+    case Chain.number_to_block(number) do
+      {:ok, _} = result -> result
+      {:error, :not_found} -> {:error, "Block number #{number} was not found."}
+    end
+  end
+end

apps/block_scout_web/lib/block_scout_web/router.ex

@@ -38,6 +38,13 @@ defmodule BlockScoutWeb.Router do
     })
   end
 
+  forward("/graphql", Absinthe.Plug, schema: BlockScoutWeb.Schema)
+
+  forward("/graphiql", Absinthe.Plug.GraphiQL,
+    schema: BlockScoutWeb.Schema,
+    interface: :playground
+  )
+
   scope "/", BlockScoutWeb do
     pipe_through(:browser)
 

apps/block_scout_web/lib/block_scout_web/schema.ex

@@ -0,0 +1,18 @@
+defmodule BlockScoutWeb.Schema do
+  @moduledoc false
+
+  use Absinthe.Schema
+
+  alias BlockScoutWeb.Resolvers.Block
+
+  import_types(Absinthe.Type.Custom)
+  import_types(BlockScoutWeb.Schema.Types)
+
+  query do
+    @desc "Gets a block by number."
+    field :block, :block do
+      arg(:number, non_null(:integer))
+      resolve(&Block.get_by/3)
+    end
+  end
+end

apps/block_scout_web/lib/block_scout_web/schema/types.ex

@@ -0,0 +1,24 @@
+defmodule BlockScoutWeb.Schema.Types do
+  @moduledoc false
+
+  use Absinthe.Schema.Notation
+
+  @desc """
+  A package of data that contains zero or more transactions, the hash of the previous block ("parent"), and optionally
+  other data. Because each block (except for the initial "genesis block") points to the previous block, the data
+  structure that they form is called a "blockchain".
+  """
+  object :block do
+    field(:consensus, :boolean)
+    field(:difficulty, :decimal)
+    field(:gas_limit, :decimal)
+    field(:gas_used, :decimal)
+    field(:nonce, :string)
+    field(:number, :integer)
+    field(:size, :integer)
+    field(:timestamp, :datetime)
+    field(:total_difficulty, :decimal)
+    field(:miner_hash, :string)
+    field(:parent_hash, :string)
+  end
+end

apps/block_scout_web/mix.exs

@@ -62,6 +62,12 @@ defmodule BlockScoutWeb.Mixfile do
   # Type `mix help deps` for examples and options.
   defp deps do
     [
+      # GraphQL toolkit
+      {:absinthe, "~> 1.4"},
+      # Integrates Absinthe subscriptions with Phoenix
+      {:absinthe_phoenix, "~> 1.4"},
+      # Plug support for Absinthe
+      {:absinthe_plug, "~> 1.4"},
       {:bypass, "~> 0.8", only: :test},
       {:cowboy, "~> 1.0"},
       {:credo, "0.9.2", only: [:dev, :test], runtime: false},

apps/block_scout_web/test/block_scout_web/schema/query/block_test.exs

@@ -0,0 +1,106 @@
+defmodule BlockScoutWeb.Schema.Query.BlockTest do
+  use BlockScoutWeb.ConnCase
+
+  describe "block field" do
+    test "with valid argument 'number', returns all expected fields", %{conn: conn} do
+      block = insert(:block)
+
+      query = """
+      query ($number: Int!) {
+        block(number: $number) {
+          consensus
+          difficulty
+          gas_limit
+          gas_used
+          nonce
+          number
+          size
+          timestamp
+          total_difficulty
+          miner_hash
+          parent_hash
+          parent_hash
+        }
+      }
+      """
+
+      variables = %{"number" => block.number}
+
+      conn = get(conn, "/graphql", query: query, variables: variables)
+
+      assert json_response(conn, 200) == %{
+               "data" => %{
+                 "block" => %{
+                   "consensus" => block.consensus,
+                   "difficulty" => to_string(block.difficulty),
+                   "gas_limit" => to_string(block.gas_limit),
+                   "gas_used" => to_string(block.gas_used),
+                   "nonce" => to_string(block.nonce),
+                   "number" => block.number,
+                   "size" => block.size,
+                   "timestamp" => DateTime.to_iso8601(block.timestamp),
+                   "total_difficulty" => to_string(block.total_difficulty),
+                   "miner_hash" => to_string(block.miner_hash),
+                   "parent_hash" => to_string(block.parent_hash)
+                 }
+               }
+             }
+    end
+
+    test "errors for non-existent block number", %{conn: conn} do
+      block = insert(:block)
+      non_existent_block_number = block.number + 1
+
+      query = """
+      query ($number: Int!) {
+        block(number: $number) {
+          number
+        }
+      }
+      """
+
+      variables = %{"number" => non_existent_block_number}
+
+      conn = get(conn, "/graphql", query: query, variables: variables)
+
+      assert %{"errors" => [error]} = json_response(conn, 200)
+      assert error["message"] =~ ~s(Block number #{non_existent_block_number} was not found)
+    end
+
+    test "errors if argument 'number' is missing", %{conn: conn} do
+      insert(:block)
+
+      query = """
+      {
+        block {
+          number
+        }
+      }
+      """
+
+      conn = get(conn, "/graphql", query: query)
+
+      assert %{"errors" => [error]} = json_response(conn, 400)
+      assert error["message"] == ~s(In argument "number": Expected type "Int!", found null.)
+    end
+
+    test "errors if argument 'number' is not an integer", %{conn: conn} do
+      insert(:block)
+
+      query = """
+      query ($number: Int!) {
+        block(number: $number) {
+          number
+        }
+      }
+      """
+
+      variables = %{"number" => "invalid"}
+
+      conn = get(conn, "/graphql", query: query, variables: variables)
+
+      assert %{"errors" => [error]} = json_response(conn, 400)
+      assert error["message"] =~ ~s(Argument "number" has invalid value)
+    end
+  end
+end

mix.lock

@@ -1,6 +1,9 @@
 %{
   "abi": {:hex, :abi, "0.1.12", "87ae04cb09e2308db7b3c350584dc3934de0e308f6a056ba82be5756b081a1ca", [:mix], [{:exth_crypto, "~> 0.1.4", [hex: :exth_crypto, repo: "hexpm", optional: false]}], "hexpm"},
   "abnf2": {:hex, :abnf2, "0.1.2", "6f8792b8ac3288dba5fc889c2bceae9fe78f74e1a7b36bea9726ffaa9d7bef95", [:mix], []},
+  "absinthe": {:hex, :absinthe, "1.4.13", "81eb2ff41f1b62cd6e992955f62c22c042d1079b7936c27f5f7c2c806b8fc436", [:mix], [{:dataloader, "~> 1.0.0", [hex: :dataloader, repo: "hexpm", optional: true]}, {:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm"},
+  "absinthe_phoenix": {:hex, :absinthe_phoenix, "1.4.3", "cea34e7ebbc9a252038c1f1164878ee86bcb108905fe462be77efacda15c1e70", [:mix], [{:absinthe, "~> 1.4.0", [hex: :absinthe, repo: "hexpm", optional: false]}, {:absinthe_plug, "~> 1.4.0", [hex: :absinthe_plug, repo: "hexpm", optional: false]}, {:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:phoenix, "~> 1.2", [hex: :phoenix, repo: "hexpm", optional: false]}, {:phoenix_html, "~> 2.10.5 or ~> 2.11", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 1.0", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}, {:poison, "~> 2.0 or ~> 3.0", [hex: :poison, repo: "hexpm", optional: false]}], "hexpm"},
+  "absinthe_plug": {:hex, :absinthe_plug, "1.4.5", "f63d52a76c870cd5f11d4bed8f61351ab5c5f572c5eb0479a0137f9f730ba33d", [:mix], [{:absinthe, "~> 1.4.11", [hex: :absinthe, repo: "hexpm", optional: false]}, {:plug, "~> 1.3.2 or ~> 1.4", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm"},
   "accept": {:hex, :accept, "0.3.3", "548ebb6fb2e8b0d170e75bb6123aea6ceecb0189bb1231eeadf52eac08384a97", [:rebar3], [], "hexpm"},
   "bcrypt_elixir": {:hex, :bcrypt_elixir, "1.0.6", "58a865939b3106d5ad4841f660955b958be6db955dda034fbbc1069dbacb97fa", [:make, :mix], [{:elixir_make, "~> 0.4", [hex: :elixir_make, optional: false]}]},
   "benchee": {:hex, :benchee, "0.13.1", "bd93ca05be78bcb6159c7176230efeda2f724f7ffd485515175ca411dff4893e", [:mix], [{:deep_merge, "~> 0.1", [hex: :deep_merge, optional: false]}]},