Merge pull request #2 from Frameio/mcaterisano/GRAPH-954/update-absin…

…the-fork-to-include-optional-run-docset-callback

[GRAPH-954] update absinthe fork to include optional run docset callback

lib/absinthe/subscription/local.ex

@@ -3,14 +3,12 @@ defmodule Absinthe.Subscription.Local do
   This module handles broadcasting documents that are local to this node
   """
 
-  # This module handles running and broadcasting documents that are local to this
-  # node.
+  require Logger
 
-  alias Absinthe.Phase
-  alias Absinthe.Pipeline
   alias Absinthe.Pipeline.BatchResolver
 
-  require Logger
+  # This module handles running and broadcasting documents that are local to this
+  # node.
 
   @doc """
   Publish a mutation to the local node only.
@@ -29,76 +27,61 @@ defmodule Absinthe.Subscription.Local do
         {topic, key_strategy, doc}
       end
 
-    run_docset(pubsub, docs_and_topics, mutation_result)
+    run_docset_fn =
+      if function_exported?(pubsub, :run_docset, 3), do: &pubsub.run_docset/3, else: &run_docset/3
 
-    :ok
-  end
+    run_docset_fn.(pubsub, docs_and_topics, mutation_result)
 
-  defp run_docset(pubsub, docs_and_topics, mutation_result) do
-    run_docset(pubsub, docs_and_topics, mutation_result, %{})
+    :ok
   end
 
-  defp run_docset(_pubsub, [], _, _memo), do: :ok
-
-  defp run_docset(pubsub, [{topic, _key_strategy, doc} | rest], mutation_result, memo) do
-    {data, updated_memo} = resolve_doc(doc, mutation_result, memo)
-    :ok = pubsub.publish_subscription(topic, data)
-    run_docset(pubsub, rest, mutation_result, updated_memo)
-  rescue
-    e ->
-      BatchResolver.pipeline_error(e, __STACKTRACE__)
-  end
+  alias Absinthe.{Phase, Pipeline}
 
-  defp resolve_doc(doc, mutation_result, memo) do
-    doc_key = get_doc_key(doc)
-
-    case Map.get(memo, doc_key) do
-      %{} = memoized_result ->
-        {memoized_result, memo}
-
-      nil ->
-        pipeline =
-          doc.initial_phases
-          |> Pipeline.replace(
-            Phase.Telemetry,
-            {Phase.Telemetry, event: [:subscription, :publish, :start]}
-          )
-          |> Pipeline.without(Phase.Subscription.SubscribeSelf)
-          |> Pipeline.insert_before(
-            Phase.Document.Execution.Resolution,
-            {Phase.Document.OverrideRoot, root_value: mutation_result}
-          )
-          |> Pipeline.upto(Phase.Document.Execution.Resolution)
-
-        pipeline = [
-          pipeline,
-          [
-            result_phase(doc),
-            {Absinthe.Phase.Telemetry, event: [:subscription, :publish, :stop]}
-          ]
-        ]
+  defp run_docset(pubsub, docs_and_topics, mutation_result) do
+    for {topic, key_strategy, doc} <- docs_and_topics do
+      try do
+        pipeline = pipeline(doc, mutation_result)
 
         {:ok, %{result: data}, _} = Absinthe.Pipeline.run(doc.source, pipeline)
 
-        updated_memo = Map.put(memo, doc_key, data)
-
-        {data, updated_memo}
+        Logger.debug("""
+        Absinthe Subscription Publication
+        Field Topic: #{inspect(key_strategy)}
+        Subscription id: #{inspect(topic)}
+        Data: #{inspect(data)}
+        """)
+
+        :ok = pubsub.publish_subscription(topic, data)
+      rescue
+        e ->
+          BatchResolver.pipeline_error(e, __STACKTRACE__)
+      end
     end
   end
 
-  defp get_doc_key(doc) do
-    variables =
-      Enum.flat_map(doc.initial_phases, fn phase ->
-        case phase do
-          {Absinthe.Phase.Document.Variables, opts} ->
-            opts[:variables]
-
-          _ ->
-            []
-        end
-      end)
-
-    :erlang.term_to_binary({doc.source, variables})
+  def pipeline(doc, mutation_result) do
+    pipeline =
+      doc.initial_phases
+      |> Pipeline.replace(
+        Phase.Telemetry,
+        {Phase.Telemetry, event: [:subscription, :publish, :start]}
+      )
+      |> Pipeline.without(Phase.Subscription.SubscribeSelf)
+      |> Pipeline.insert_before(
+        Phase.Document.Execution.Resolution,
+        {Phase.Document.OverrideRoot, root_value: mutation_result}
+      )
+      |> Pipeline.upto(Phase.Document.Execution.Resolution)
+
+    pipeline = [
+      pipeline,
+      [
+        result_phase(doc),
+        {Absinthe.Phase.Telemetry, event: [:subscription, :publish, :stop]}
+      ]
+    ]
+
+    pipeline
   end
 
   defp get_docs(pubsub, field, mutation_result, topic: topic_fun)

lib/absinthe/subscription/pubsub.ex

@@ -73,4 +73,12 @@ defmodule Absinthe.Subscription.Pubsub do
   only.
   """
   @callback publish_subscription(topic :: binary, data :: map) :: term
+
+  # @doc """
+  # This function is called by publish_mutation and is responsible for resolving the documents
+  # and publishing the results to the appropriate topics.
+  # """
+  @callback run_docset(pubsub :: t, docs_and_topics :: list, mutation_result :: term) :: term
+
+  @optional_callbacks run_docset: 3
 end

test/absinthe/execution/subscription_test.exs

@@ -79,6 +79,47 @@ defmodule Absinthe.Execution.SubscriptionTest do
     end
   end
 
+  defmodule PubSubWithDocsetRunner do
+    @behaviour Absinthe.Subscription.Pubsub
+
+    def start_link() do
+      Registry.start_link(keys: :duplicate, name: __MODULE__)
+    end
+
+    def node_name() do
+      node()
+    end
+
+    def subscribe(topic) do
+      Registry.register(__MODULE__, topic, [])
+      :ok
+    end
+
+    def publish_subscription(topic, data) do
+      message = %{
+        topic: topic,
+        event: "subscription:data",
+        result: data
+      }
+
+      Registry.dispatch(__MODULE__, topic, fn entries ->
+        for {pid, _} <- entries, do: send(pid, {:broadcast, message})
+      end)
+    end
+
+    def publish_mutation(_proxy_topic, _mutation_result, _subscribed_fields) do
+      # this pubsub is local and doesn't support clusters
+      :ok
+    end
+
+    def run_docset(pubsub, docs_and_topics, _mutation_result) do
+      for {topic, _key_strategy, _doc} <- docs_and_topics do
+        # publish mutation results to topic
+        pubsub.publish_subscription(topic, %{data: %{runner: "calls the custom docset runner"}})
+      end
+    end
+  end
+
   defmodule Schema do
     use Absinthe.Schema
 
@@ -189,6 +230,9 @@ defmodule Absinthe.Execution.SubscriptionTest do
   setup_all do
     {:ok, _} = PubSub.start_link()
     {:ok, _} = Absinthe.Subscription.start_link(PubSub)
+
+    {:ok, _} = PubSubWithDocsetRunner.start_link()
+    {:ok, _} = Absinthe.Subscription.start_link(PubSubWithDocsetRunner)
     :ok
   end
 
@@ -643,9 +687,7 @@ defmodule Absinthe.Execution.SubscriptionTest do
         [:absinthe, :subscription, :publish, :start],
         [:absinthe, :subscription, :publish, :stop]
       ],
-      fn event, measurements, metadata, config ->
-        send(self(), {event, measurements, metadata, config})
-      end,
+      &Absinthe.TestTelemetryHelper.send_to_pid/4,
       %{}
     )
 
@@ -657,10 +699,13 @@ defmodule Absinthe.Execution.SubscriptionTest do
                context: %{pubsub: PubSub}
              )
 
-    assert_receive {[:absinthe, :execute, :operation, :start], measurements, %{id: id}, _config}
+    assert_receive {:telemetry_event,
+                    {[:absinthe, :execute, :operation, :start], measurements, %{id: id}, _config}}
+
     assert System.convert_time_unit(measurements[:system_time], :native, :millisecond)
 
-    assert_receive {[:absinthe, :execute, :operation, :stop], _, %{id: ^id}, _config}
+    assert_receive {:telemetry_event,
+                    {[:absinthe, :execute, :operation, :stop], _, %{id: ^id}, _config}}
 
     Absinthe.Subscription.publish(PubSub, "foo", thing: client_id)
     assert_receive({:broadcast, msg})
@@ -672,8 +717,11 @@ defmodule Absinthe.Execution.SubscriptionTest do
            } == msg
 
     # Subscription events
-    assert_receive {[:absinthe, :subscription, :publish, :start], _, %{id: id}, _config}
-    assert_receive {[:absinthe, :subscription, :publish, :stop], _, %{id: ^id}, _config}
+    assert_receive {:telemetry_event,
+                    {[:absinthe, :subscription, :publish, :start], _, %{id: id}, _config}}
+
+    assert_receive {:telemetry_event,
+                    {[:absinthe, :subscription, :publish, :stop], _, %{id: ^id}, _config}}
 
     :telemetry.detach(context.test)
   end
@@ -715,12 +763,55 @@ defmodule Absinthe.Execution.SubscriptionTest do
     refute_receive({:broadcast, _})
   end
 
-  defp run_subscription(query, schema, opts \\ []) do
-    opts = Keyword.update(opts, :context, %{pubsub: PubSub}, &Map.put(&1, :pubsub, PubSub))
+  @query """
+  subscription ($userId: ID!) {
+    user(id: $userId) { id name }
+  }
+  """
+  test "calls the optional run_docset callback if supplied" do
+    id = "1"
+
+    assert {:ok, %{"subscribed" => topic}} =
+             run_subscription(
+               @query,
+               Schema,
+               variables: %{"userId" => id},
+               context: %{pubsub: PubSubWithDocsetRunner}
+             )
+
+    mutation = """
+    mutation ($userId: ID!) {
+      updateUser(id: $userId) { id name }
+    }
+    """
+
+    assert {:ok, %{data: _}} =
+             run_subscription(mutation, Schema,
+               variables: %{"userId" => id},
+               context: %{pubsub: PubSubWithDocsetRunner}
+             )
+
+    assert_receive({:broadcast, msg})
+
+    assert %{
+             event: "subscription:data",
+             result: %{data: %{runner: "calls the custom docset runner"}},
+             topic: topic
+           } == msg
+  end
+
+  def run_subscription(query, schema, opts \\ []) do
+    opts =
+      Keyword.update(
+        opts,
+        :context,
+        %{pubsub: PubSub},
+        &Map.put(&1, :pubsub, opts[:context][:pubsub] || PubSub)
+      )
 
     case run(query, schema, opts) do
       {:ok, %{"subscribed" => topic}} = val ->
-        PubSub.subscribe(topic)
+        opts[:context][:pubsub].subscribe(topic)
         val
 
       val ->