Fixed GraphQL schema does not support operation validation. (#8125)

Author: michaelstaib

src/HotChocolate/Core/src/Validation/ErrorHelper.cs

@@ -280,6 +280,17 @@ public static IError FieldsAreNotMergeable(
             .Build();
     }
 
+    public static IError OperationNotSupported(
+        this IDocumentValidatorContext context,
+        OperationType operationType)
+    {
+        return ErrorBuilder.New()
+            .SetMessage(
+                Resources.ErrorHelper_OperationNotSupported,
+                operationType)
+            .Build();
+    }
+
     public static IError FragmentNameNotUnique(
         this IDocumentValidatorContext context,
         FragmentDefinitionNode fragmentDefinition)

src/HotChocolate/Core/src/Validation/Properties/Resources.Designer.cs

@@ -230,4 +230,7 @@
   <data name="ErrorHelper_DeferAndStreamLabelIsVariable" xml:space="preserve">
     <value>If a label for @defer or @stream is passed, it must not be a variable.</value>
   </data>
+  <data name="ErrorHelper_OperationNotSupported" xml:space="preserve">
+    <value>This GraphQL schema does not support `{0}` operations.</value>
+  </data>
 </root>

src/HotChocolate/Core/src/Validation/Properties/Resources.resx

@@ -32,6 +32,14 @@ protected override ISyntaxVisitorAction Enter(
         OperationDefinitionNode node,
         IDocumentValidatorContext context)
     {
+        var operationType = context.Schema.GetOperationType(node.Operation);
+
+        if (operationType == null)
+        {
+            context.ReportError(context.OperationNotSupported(node.Operation));
+            return Skip;
+        }
+
         context.FieldSets.Clear();
         context.SelectionSets.Clear();
 

src/HotChocolate/Core/src/Validation/Rules/FieldVisitor.cs

@@ -1,7 +1,7 @@
 {
   "errors": [
     {
-      "message": "The specified root type `Mutation` is not supported by this server."
+      "message": "This GraphQL schema does not support `Mutation` operations."
     }
   ]
 }

src/HotChocolate/Core/test/Execution.Tests/Errors/__snapshots__/ErrorBehaviorTests.RootTypeNotDefined.json

@@ -243,4 +243,41 @@ fragment interfaceFieldSelection on Cat {
         // assert
         Assert.Empty(context.Errors);
     }
+
+    [Fact]
+    public void Ensure_Non_Existent_Root_Types_Cause_Error()
+    {
+        // arrange
+        IDocumentValidatorContext context = ValidationUtils.CreateContext(CreateQueryOnlySchema());
+        var query = Utf8GraphQLParser.Parse(
+            """
+            subscription {
+                foo
+            }
+            """);
+        context.Prepare(query);
+
+        // act
+        Rule.Validate(context, query);
+
+        // assert
+        Assert.Collection(
+            context.Errors,
+            t => Assert.Equal(
+                "This GraphQL schema does not support `Subscription` operations.",
+                t.Message));
+    }
+
+    private ISchema CreateQueryOnlySchema()
+    {
+        return SchemaBuilder.New()
+            .AddDocumentFromString(
+                """
+                type Query {
+                    foo: String
+                }
+                """)
+            .Use(next => next)
+            .Create();
+    }
 }

src/HotChocolate/Core/test/Validation.Tests/FieldMustBeDefinedRuleTests.cs

@@ -95,6 +95,59 @@ await snapshot
             .MatchMarkdownAsync();
     }
 
+    [Fact]
+    public async Task Execute_On_Missing_Root_Type()
+    {
+        // arrange
+        var snapshot = new Snapshot();
+
+        var operation =
+            Utf8GraphQLParser.Parse(
+                """
+                subscription {
+                    books {
+                        nodes {
+                            title
+                        }
+                    }
+                }
+                """);
+
+        var request =
+            OperationRequestBuilder.New()
+                .SetDocument(operation)
+                .ReportCost()
+                .Build();
+
+        var executor =
+            await new ServiceCollection()
+                .AddGraphQLServer()
+                .AddQueryType<Query>()
+                .ModifyPagingOptions(o => o.RequirePagingBoundaries = false)
+                .AddFiltering()
+                .AddSorting()
+                .BuildRequestExecutorAsync();
+
+        // act
+        var response = await executor.ExecuteAsync(request);
+
+        // assert
+        var expectation =
+            JsonDocument.Parse(
+                """
+                {
+                    "fieldCost": 6,
+                    "typeCost": 12
+                }
+                """);
+
+        await snapshot
+            .Add(operation, "Operation")
+            .Add(expectation.RootElement, "Expected")
+            .Add(response, "Response")
+            .MatchMarkdownAsync();
+    }
+
     [Fact]
     public async Task Require_Paging_Boundaries_By_Default_With_Connections()
     {

src/HotChocolate/CostAnalysis/test/CostAnalysis.Tests/PagingTests.cs

@@ -0,0 +1,35 @@
+# Execute_On_Missing_Root_Type
+
+## Operation
+
+```graphql
+subscription {
+  books {
+    nodes {
+      title
+    }
+  }
+}
+```
+
+## Expected
+
+```json
+{
+  "fieldCost": 6,
+  "typeCost": 12
+}
+```
+
+## Response
+
+```json
+{
+  "errors": [
+    {
+      "message": "This GraphQL schema does not support `Subscription` operations."
+    }
+  ]
+}
+```
+