Catch exceptions, raise Plug.Conn.WrapperError

.github/workflows/elixir.yml

@@ -9,7 +9,7 @@ on:
 jobs:
   test:
     name: Elixir ${{matrix.elixir}} / OTP ${{matrix.otp}}
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
 
     strategy:
       matrix:

lib/absinthe/plug.ex

@@ -286,37 +286,43 @@ defmodule Absinthe.Plug do
   """
   @spec call(Plug.Conn.t(), map) :: Plug.Conn.t() | no_return
   def call(conn, config) do
-    config = update_config(conn, config)
-    {conn, result} = conn |> execute(config)
-
-    case result do
-      {:input_error, msg} ->
-        conn
-        |> encode(400, error_result(msg), config)
-
-      {:ok, %{"subscribed" => topic}} ->
-        conn
-        |> subscribe(topic, config)
-
-      {:ok, %{data: _} = result} ->
-        conn
-        |> encode(200, result, config)
-
-      {:ok, %{errors: _} = result} ->
-        conn
-        |> encode(200, result, config)
-
-      {:ok, result} when is_list(result) ->
-        conn
-        |> encode(200, result, config)
-
-      {:error, {:http_method, text}, _} ->
-        conn
-        |> encode(405, error_result(text), config)
-
-      {:error, error, _} when is_binary(error) ->
-        conn
-        |> encode(500, error_result(error), config)
+    try do
+      config = update_config(conn, config)
+      {conn, result} = conn |> execute(config)
+
+      case result do
+        {:input_error, msg} ->
+          conn
+          |> encode(400, error_result(msg), config)
+
+        {:ok, %{"subscribed" => topic}} ->
+          conn
+          |> subscribe(topic, config)
+
+        {:ok, %{data: _} = result} ->
+          conn
+          |> encode(200, result, config)
+
+        {:ok, %{errors: _} = result} ->
+          conn
+          |> encode(200, result, config)
+
+        {:ok, result} when is_list(result) ->
+          conn
+          |> encode(200, result, config)
+
+        {:error, {:http_method, text}, _} ->
+          conn
+          |> encode(405, error_result(text), config)
+
+        {:error, error, _} when is_binary(error) ->
+          conn
+          |> encode(500, error_result(error), config)
+      end
+    catch
+      kind, reason ->
+        stack = __STACKTRACE__
+        Plug.Conn.WrapperError.reraise(conn, kind, reason, stack)
     end
   end
 

test/lib/absinthe/plug/document_provider_test.exs

@@ -50,7 +50,7 @@ defmodule Absinthe.Plug.DocumentProviderTest do
 
   test "cannot process without any document providers" do
     opts = Absinthe.Plug.init(schema: TestSchema, document_providers: [])
-    assert_raise RuntimeError, fn -> request(opts) end
+    assert_raise Plug.Conn.WrapperError, fn -> request(opts) end
   end
 
   defp request(opts) do

test/lib/absinthe/plug_test.exs

@@ -707,6 +707,21 @@ defmodule Absinthe.PlugTest do
     end
   end
 
+  test "raises wrapped error with plugged conn on uncaught exceptions" do
+    opts = Absinthe.Plug.init(schema: TestSchema)
+    body = %{query: "{ exceptionRaising }"}
+
+    exception =
+      assert_raise Plug.Conn.WrapperError, fn ->
+        conn(:post, "/", body)
+        |> put_req_header("content-type", "application/json")
+        |> plug_parser
+        |> Absinthe.Plug.call(opts)
+      end
+
+    assert exception.conn.body_params == %{"query" => "{ exceptionRaising }"}
+  end
+
   def test_before_send(conn, val) do
     # just for easy testing
     send(self(), {:before_send, val})

test/support/test_schema.ex

@@ -66,6 +66,12 @@ defmodule Absinthe.Plug.TestSchema do
         raise "complex string must not be resolved"
       end
     end
+
+    field :exception_raising, :string do
+      resolve fn _, _ ->
+        raise "uncaught exception"
+      end
+    end
   end
 
   subscription do