From 7386a5b627a98d5af9a83c50b4726513e0ac274a Mon Sep 17 00:00:00 2001
From: Alan Heywood <alan@softweb.net.au>
Date: Sat, 4 May 2024 11:57:02 +1000
Subject: [PATCH] improvement: make mutation result errors list non-nullable
 (#144)

* chore: regenerate cheat sheets

* improvement: make mutation result errors list non-nullable
---
 documentation/dsls/DSL:-AshGraphql.Domain.md |   4 +-
 lib/resource/resource.ex                     |   8 +-
 test/errors_test.exs                         | 103 ++++++++++++++-----
 3 files changed, 84 insertions(+), 31 deletions(-)

diff --git a/documentation/dsls/DSL:-AshGraphql.Domain.md b/documentation/dsls/DSL:-AshGraphql.Domain.md
index 95e96a9..593bc88 100644
--- a/documentation/dsls/DSL:-AshGraphql.Domain.md
+++ b/documentation/dsls/DSL:-AshGraphql.Domain.md
@@ -3,11 +3,11 @@ This file was generated by Spark. Do not edit it by hand.
 -->
 # DSL: AshGraphql.Domain
 
-The entrypoint for adding graphql behavior to an Ash domain
+The entrypoint for adding GraphQL behavior to an Ash domain
 
 
 ## graphql
-Global configuration for graphql
+Domain level configuration for GraphQL
 
 
 
diff --git a/lib/resource/resource.ex b/lib/resource/resource.ex
index 56b3c83..79c2e2d 100644
--- a/lib/resource/resource.ex
+++ b/lib/resource/resource.ex
@@ -930,9 +930,11 @@ defmodule AshGraphql.Resource do
           identifier: :errors,
           module: schema,
           name: "errors",
-          type: %Absinthe.Blueprint.TypeReference.List{
-            of_type: %Absinthe.Blueprint.TypeReference.NonNull{
-              of_type: :mutation_error
+          type: %Absinthe.Blueprint.TypeReference.NonNull{
+            of_type: %Absinthe.Blueprint.TypeReference.List{
+              of_type: %Absinthe.Blueprint.TypeReference.NonNull{
+                of_type: :mutation_error
+              }
             }
           },
           __reference__: ref(__ENV__)
diff --git a/test/errors_test.exs b/test/errors_test.exs
index 12300f1..40fdeb1 100644
--- a/test/errors_test.exs
+++ b/test/errors_test.exs
@@ -11,34 +11,72 @@ defmodule AshGraphql.ErrorsTest do
     end)
   end
 
-  test "errors can be configured to be shown in the root" do
-    resp =
-      """
-      mutation CreatePost($input: CreatePostInput) {
-        createPost(input: $input) {
-          result{
-            text
-          }
-          errors{
-            message
+  describe "when root level errors are enabled" do
+    test "errors that occur are shown at the root level" do
+      resp =
+        """
+        mutation CreatePost($input: CreatePostInput) {
+          createPost(input: $input) {
+            result{
+              text
+            }
+            errors{
+              message
+            }
           }
         }
-      }
-      """
-      |> Absinthe.run(AshGraphql.Test.RootLevelErrorsSchema,
-        variables: %{
-          "input" => %{
-            "text" => "foobar",
-            "confirmation" => "foobar2"
+        """
+        |> Absinthe.run(AshGraphql.Test.RootLevelErrorsSchema,
+          variables: %{
+            "input" => %{
+              "text" => "foobar",
+              "confirmation" => "foobar2"
+            }
+          }
+        )
+
+      assert {:ok, result} = resp
+
+      assert %{data: %{"createPost" => nil}, errors: [%{message: message}]} = result
+      assert message =~ "confirmation did not match value"
+    end
+
+    test "the root level errors field is not present when no errors occur" do
+      resp =
+        """
+        mutation CreatePost($input: CreatePostInput) {
+          createPost(input: $input) {
+            result{
+              text
+            }
+            errors{
+              message
+            }
           }
         }
-      )
+        """
+        |> Absinthe.run(AshGraphql.Test.RootLevelErrorsSchema,
+          variables: %{
+            "input" => %{
+              "text" => "foobar",
+              "confirmation" => "foobar"
+            }
+          }
+        )
 
-    assert {:ok, result} = resp
+      assert {:ok, result} = resp
 
-    assert %{data: %{"createPost" => nil}, errors: [%{message: message}]} = result
+      assert %{
+               data: %{
+                 "createPost" => %{
+                   "result" => %{"text" => "foobar"},
+                   "errors" => []
+                 }
+               }
+             } = result
 
-    assert message =~ "confirmation did not match value"
+      refute Map.has_key?(result, :errors)
+    end
   end
 
   test "raised errors are by default not shown" do
@@ -354,7 +392,7 @@ defmodule AshGraphql.ErrorsTest do
     assert message =~ "Breakdown"
   end
 
-  test "error items are non-nullable" do
+  test "error items are a non-nullable list of non-nullables" do
     {:ok, %{data: data}} =
       """
       query {
@@ -366,7 +404,10 @@ defmodule AshGraphql.ErrorsTest do
               ofType {
                 kind
                 ofType {
-                  name
+                  kind
+                  ofType {
+                    name
+                  }
                 }
               }
             }
@@ -380,9 +421,19 @@ defmodule AshGraphql.ErrorsTest do
       data["__type"]["fields"]
       |> Enum.find(fn field -> field["name"] == "errors" end)
 
-    assert errors["type"]["kind"] == "LIST"
-    assert errors["type"]["ofType"]["kind"] == "NON_NULL"
-    assert errors["type"]["ofType"]["ofType"]["name"] == "MutationError"
+    assert errors == %{
+             "name" => "errors",
+             "type" => %{
+               "kind" => "NON_NULL",
+               "ofType" => %{
+                 "kind" => "LIST",
+                 "ofType" => %{
+                   "kind" => "NON_NULL",
+                   "ofType" => %{"name" => "MutationError"}
+                 }
+               }
+             }
+           }
   end
 
   test "MutationError fields items are non-nullable" do