Attach to subscription publish events

lib/instrumentation.ex

@@ -55,7 +55,8 @@ defmodule OpentelemetryAbsinthe.Instrumentation do
     trace_request_selections: true,
     trace_response_result: false,
     trace_response_errors: false,
-    trace_subscriptions: false
+    trace_subscriptions: false,
+    status_function: nil
   ]
 
   def setup(instrumentation_opts \\ []) do
@@ -137,7 +138,7 @@ defmodule OpentelemetryAbsinthe.Instrumentation do
     |> Tracer.update_name()
 
     errors = data.blueprint.result[:errors]
-    status = status(errors)
+    status = status(errors, data, config)
     set_status(status)
 
     []
@@ -174,12 +175,15 @@ defmodule OpentelemetryAbsinthe.Instrumentation do
   end
 
   defp get_graphql_selections(%{blueprint: %Blueprint{} = blueprint}) do
-    blueprint
-    |> Blueprint.current_operation()
-    |> Kernel.||(%{})
-    |> Map.get(:selections, [])
-    |> Enum.map(& &1.name)
-    |> Enum.uniq()
+    case Blueprint.current_operation(blueprint) do
+      %{selections: [_ | _] = selections} ->
+        selections
+        |> Enum.map(&Map.fetch!(&1, :name))
+        |> Enum.uniq()
+
+      _ ->
+        []
+    end
   end
 
   def default_config do
@@ -220,9 +224,20 @@ defmodule OpentelemetryAbsinthe.Instrumentation do
     Tracer.set_current_span(ctx)
   end
 
-  defp status(nil), do: :ok
-  defp status([]), do: :ok
-  defp status(_error), do: :error
+  defp status(_errors, data, %{status_function: {module, function}}) do
+    case apply(module, function, [data]) do
+      expected when expected in [:ok, :error] ->
+        expected
+
+      other ->
+        Logger.error("Unexpected value returned by status function #{inspect(other)}")
+        :error
+    end
+  end
+
+  defp status(nil, _, _), do: :ok
+  defp status([], _, _), do: :ok
+  defp status(_error, _, _), do: :error
 
   defp set_status(:ok), do: :ok
   defp set_status(:error), do: Tracer.set_status(OpenTelemetry.status(:error, ""))

lib/opentelemetry_absinthe.ex

@@ -73,6 +73,8 @@ defmodule OpentelemetryAbsinthe do
     * `trace_response_result`(default: #{Keyword.fetch!(@config, :trace_response_result)}): attaches the result returned by the server as an attribute
     * `trace_response_errors`(default: #{Keyword.fetch!(@config, :trace_response_errors)}): attaches the errors returned by the server as an attribute
     * `trace_subscriptions`(default: #{Keyword.fetch!(@config, :trace_subscriptions)}): attaches to `[:absinthe, :subscription, :publish]` (`:start` and `:stop`)
+    * `status_function`(default: #{Keyword.fetch!(@config, :status_function)}): a `{module, function}` tuple for a function which will be executed to infer the status
+    of the trace. This function __must__ return `:ok | :error`
 
   ## Telemetry
 

test/instrumentation_test.exs

@@ -78,6 +78,43 @@ defmodule OpentelemetryAbsintheTest.InstrumentationTest do
                      10
     end
 
+    test "status function works", ctx do
+      defmodule Helper do
+        def status_function(_) do
+          :error
+        end
+      end
+
+      config = %{ctx.config | status_function: {Helper, :status_function}}
+
+      assert :ok =
+               :telemetry.attach(
+                 ctx.test,
+                 [:opentelemetry_absinthe, :graphql, :handled],
+                 fn _telemetry_event, _measurements, metadata, _config ->
+                   send(self(), metadata)
+                 end,
+                 nil
+               )
+
+      assert :ok =
+               Instrumentation.handle_stop(
+                 "Test",
+                 %{},
+                 %{blueprint: BlueprintArchitect.blueprint(schema: __MODULE__)},
+                 config
+               )
+
+      assert_receive %{
+                       operation_name: "TestOperation",
+                       operation_type: :query,
+                       schema: __MODULE__,
+                       errors: nil,
+                       status: :error
+                     },
+                     10
+    end
+
     test "standard values are returned alongside the metadata from context", ctx do
       context = TelemetryMetadata.update_context(%{}, %{source: "TestSource", user_agent: "Insomnia"})