Introduced subgraph consistency check. (#6493)

.mono/registry/CurrentUser/software/microsoft/csdevkit/v1/pids/61843_133378542792508790/values.xml

@@ -0,0 +1,3 @@
+<values>
+  <value name="StillAlive" type="qword">133378551816226300</value>
+</values>

src/HotChocolate/Fusion/src/Composition/LogEntryHelper.cs

@@ -114,6 +114,15 @@ public static LogEntry FieldDependencyCannotBeResolved(
             code: LogEntryCodes.FieldDependencyCannotBeResolved,
             coordinate: coordinate,
             schema: schema);
+
+    public static LogEntry TypeNotDeclared(MissingType type, Schema schema)
+        => new(
+            string.Format(LogEntryHelper_TypeNotDeclared, type.Name, schema.Name),
+            LogEntryCodes.TypeNotDeclared,
+            severity: LogSeverity.Error,
+            coordinate: new SchemaCoordinate(type.Name),
+            member: type,
+            schema: schema);
 }
 
 static file class LogEntryCodes
@@ -133,4 +142,6 @@ static file class LogEntryCodes
     public const string CoordinateNotAllowedForRequirements = "HF0007";
 
     public const string FieldDependencyCannotBeResolved = "HF0008";
+
+    public const string TypeNotDeclared = "HF0009";
 }

src/HotChocolate/Fusion/src/Composition/Pipeline/ParseSubGraphSchemaMiddleware.cs

@@ -2,6 +2,7 @@
 using HotChocolate.Language;
 using HotChocolate.Skimmed;
 using HotChocolate.Skimmed.Serialization;
+using static HotChocolate.Fusion.Composition.LogEntryHelper;
 using IHasDirectives = HotChocolate.Skimmed.IHasDirectives;
 
 namespace HotChocolate.Fusion.Composition.Pipeline;
@@ -29,6 +30,11 @@ public async ValueTask InvokeAsync(CompositionContext context, MergeDelegate nex
             {
                 context.Subgraphs.Add(schema);
             }
+
+            foreach (var missingType in schema.Types.OfType<MissingType>())
+            {
+                context.Log.Write(TypeNotDeclared(missingType, schema));
+            }
         }
 
         await next(context).ConfigureAwait(false);
@@ -112,7 +118,7 @@ private static void TryCreateMissingType<T>(
             if (targetType.Kind != sourceType.Kind)
             {
                 context.Log.Write(
-                    LogEntryHelper.MergeTypeKindDoesNotMatch(
+                    MergeTypeKindDoesNotMatch(
                         sourceType,
                         sourceType.Kind,
                         targetType.Kind));

src/HotChocolate/Fusion/src/Composition/Properties/CompositionResources.resx

@@ -63,4 +63,7 @@ Source Arguments: {2}</value>
   <data name="DirectivesHelper_GetRequireDirective_NoFieldArg" xml:space="preserve">
     <value>The require directive must have a value for the argument field.</value>
   </data>
+  <data name="LogEntryHelper_TypeNotDeclared" xml:space="preserve">
+    <value>The type `{0}` is not declared on subgraph {1}. Check the subgraph schema for consistency.</value>
+  </data>
 </root>

src/HotChocolate/Fusion/test/Composition.Tests/ErrorTests.cs

@@ -0,0 +1,109 @@
+using CookieCrumble;
+using HotChocolate.Fusion.Shared;
+using HotChocolate.Skimmed.Serialization;
+using Xunit.Abstractions;
+
+namespace HotChocolate.Fusion.Composition;
+
+public class ErrorTests
+{
+    private readonly ITestOutputHelper _output;
+    private readonly Func<ICompositionLog> _logFactory;
+
+    public ErrorTests(ITestOutputHelper output)
+    {
+        _output = output;
+        _logFactory = () => new TestCompositionLog(output);
+    }
+
+    [Fact]
+    public async Task Typo_In_Schema()
+    {
+        const string schema =
+            """
+            type Author {
+                id: ID!
+                reviews: ReviewConnection
+            }
+
+            type Book {
+                id: ID!
+                reviews: ReviewConnection
+            }
+
+            input CreateReviewInput {
+                bookId: ID!
+                reviewerId: ID!
+                authorId: ID!
+                comment: String!
+                rating: Int!
+            }
+
+            input DeleteReviewInput {
+                id: ID!
+            }
+
+            type Review {
+                id: ID!
+                bookId: ID!
+                reviewerId: ID!
+                authorId: ID!
+                comment: String!
+                rating: Int!
+            }
+
+            type ReviewConnection {
+                items: [Review]
+                nextToken: String
+            }
+
+
+            type Mutation {
+                createReview(input: CreateReviewInput!): Review
+                deleteReview(input: DeleteReviewInput!): Review
+            }
+
+            type Query {
+                getReview(id: ID!): Review
+                listReviews(limit: Int, nextToken: String): ReviewConnection
+                queryReviewsByBook(bookId: ID!, limit: int, nextToken: String): ReviewConnection
+                queryReviewsByReviewer(reviewerId: ID!, limit: int, nextToken: String): ReviewConnection
+                queryReviewsByAuthor(authorId: ID!, limit: int, nextToken: String): ReviewConnection
+            }
+
+            schema {
+                query: Query,
+                mutation: Mutation
+            }
+            """;
+
+        var log = new ErrorCompositionLog();
+        var composer = new FusionGraphComposer(logFactory: () => log);
+
+        var fusionConfig = await composer.TryComposeAsync(
+            new[]
+            {
+                new SubgraphConfiguration(
+                    "Test123",
+                    schema,
+                    Array.Empty<string>(),
+                    new IClientConfiguration[]
+                    {
+                        new HttpClientConfiguration(new Uri("http://localhost"))
+                    })
+            });
+
+        Assert.Null(fusionConfig);
+        Assert.True(log.HasErrors);
+        Assert.Collection(
+            log.Errors,
+            a =>
+            {
+                Assert.Equal(
+                    "The type `int` is not declared on subgraph Test123. " +
+                    "Check the subgraph schema for consistency.", 
+                    a.Message);
+                Assert.Equal("HF0009", a.Code);
+            });
+    }
+}

src/HotChocolate/Fusion/test/Shared/TestCompositionLog.cs

@@ -24,3 +24,20 @@ public void Write(LogEntry entry)
         _output.WriteLine(entry.Message);
     }
 }
+
+public sealed class ErrorCompositionLog : ICompositionLog
+{
+    private readonly List<LogEntry> _errors = new();
+
+    public bool HasErrors => _errors.Count > 0;
+
+    public List<LogEntry> Errors => _errors;
+
+    public void Write(LogEntry entry)
+    {
+        if(entry.Severity == LogSeverity.Error)
+        {
+            _errors.Add(entry);
+        }
+    }
+}