fix(scope-resolution): fan out C# Record interface calls (#2904)

* fix(scope-resolution): fan out C# Record interface calls

Use the shared class-like predicate so canonical C# Record implementors participate in interface dispatch, and pin the missing call edge with a regression test.

Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(scope-resolution): preserve partial Record dispatch

Keep every scope definition that shares a graph node so interface fan-out is independent of partial declaration order, and strengthen C# dispatch controls.

Co-authored-by: Cursor <cursoragent@cursor.com>

---------

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: Gergő Magyar <gergomagyar@icloud.com>

gitnexus/src/core/ingestion/scope-resolution/passes/receiver-bound-calls.ts

@@ -326,17 +326,22 @@ export function emitReceiverBoundCalls(
     isBuiltInName: options.isBuiltInName,
   };
 
-  // Build an interface → implementors map from IMPLEMENTS edges.
-  // Maps Interface graph-id → list of implementor class scope-def-ids.
-  // We translate graph-ids back to scope-resolution DefIds via
-  // `parsedFiles.localDefs` lookup so downstream `findOwnedMember`
-  // (which keys by DefId) can find the implementor's members.
-  const graphIdToClassDef = new Map<string, SymbolDefinition>();
+  // Maps class-like graph ids back to ALL scope definitions that resolved to
+  // them. Same-file partial declarations share one graph id but keep distinct
+  // DefIds, and `pickOverload` keys member lookup by those DefIds. Preserving
+  // every part makes dispatch independent of declaration order.
+  const graphIdToClassDefs = new Map<string, SymbolDefinition[]>();
   for (const parsed of parsedFiles) {
     for (const def of parsed.localDefs) {
-      if (def.type !== 'Class' && def.type !== 'Struct' && def.type !== 'Interface') continue;
+      if (!isClassLike(def.type)) continue;
       const graphId = resolveDefGraphId(parsed.filePath, def, nodeLookup);
-      if (graphId !== undefined) graphIdToClassDef.set(graphId, def);
+      if (graphId === undefined) continue;
+      let defs = graphIdToClassDefs.get(graphId);
+      if (defs === undefined) {
+        defs = [];
+        graphIdToClassDefs.set(graphId, defs);
+      }
+      defs.push(def);
     }
   }
   // Direct subtypes of a type, keyed by the SUPERtype's def id.
@@ -360,10 +365,12 @@ export function emitReceiverBoundCalls(
   };
   for (const relType of ['IMPLEMENTS', 'EXTENDS'] as const) {
     for (const rel of graph.iterRelationshipsByType(relType)) {
-      const superDef = graphIdToClassDef.get(rel.targetId);
-      const subDef = graphIdToClassDef.get(rel.sourceId);
-      if (superDef === undefined || subDef === undefined) continue;
-      addSubtype(superDef.nodeId, subDef);
+      const superDefs = graphIdToClassDefs.get(rel.targetId);
+      const subDefs = graphIdToClassDefs.get(rel.sourceId);
+      if (superDefs === undefined || subDefs === undefined) continue;
+      for (const superDef of superDefs) {
+        for (const subDef of subDefs) addSubtype(superDef.nodeId, subDef);
+      }
     }
   }
 

gitnexus/test/integration/resolvers/csharp.test.ts

@@ -2353,6 +2353,82 @@ describe('C# record base resolution (record inheritance + base.Save)', () => {
     }
   }, 60000);
 
+  it('fans interface calls out to an implementing Record method (#2884)', async () => {
+    const root = fs.mkdtempSync(path.join(os.tmpdir(), 'gitnexus-csharp-record-dispatch-'));
+    try {
+      writeFixtureRepo(root, {
+        'INamed.cs': 'namespace Probe; public interface INamed { string Name(); }',
+        'User.cs': `namespace Probe;
+          public record User(string Value) : INamed {
+            public string Name() => Value;
+          }`,
+        'Reader.cs': `namespace Probe;
+          public class Reader {
+            public string Read(INamed value) => value.Name();
+            public string ReadConcrete(User value) => value.Name();
+          }`,
+      });
+
+      const linked = await runPipelineFromRepo(root, () => {});
+      const calls = getRelationships(linked, 'CALLS');
+      const primary = calls.filter(
+        (edge) =>
+          edge.source === 'Read' &&
+          edge.target === 'Name' &&
+          edge.rel.reason !== 'interface-dispatch',
+      );
+      const fanout = calls.filter(
+        (edge) =>
+          edge.source === 'Read' &&
+          edge.target === 'Name' &&
+          edge.rel.reason === 'interface-dispatch',
+      );
+      const concreteFanout = calls.filter(
+        (edge) =>
+          edge.source === 'ReadConcrete' &&
+          edge.target === 'Name' &&
+          edge.rel.reason === 'interface-dispatch',
+      );
+
+      expect(primary.map((edge) => `${edge.targetLabel}:${edge.targetFilePath}`)).toEqual([
+        'Method:INamed.cs',
+      ]);
+      expect(fanout.map((edge) => `${edge.targetLabel}:${edge.targetFilePath}`)).toEqual([
+        'Method:User.cs',
+      ]);
+      expect(concreteFanout).toEqual([]);
+    } finally {
+      fs.rmSync(root, { recursive: true, force: true });
+    }
+  }, 60000);
+
+  it('fans out through reversed same-file partial Record declarations (#2884)', async () => {
+    const root = fs.mkdtempSync(path.join(os.tmpdir(), 'gitnexus-csharp-partial-record-dispatch-'));
+    try {
+      writeFixtureRepo(root, {
+        'All.cs': `namespace Probe;
+          public interface INamed { string Name(); }
+          public partial record User { public string Name() => "u"; }
+          public partial record User : INamed { }
+          public class Reader { public string Read(INamed value) => value.Name(); }`,
+      });
+
+      const linked = await runPipelineFromRepo(root, () => {});
+      const fanout = getRelationships(linked, 'CALLS').filter(
+        (edge) =>
+          edge.source === 'Read' &&
+          edge.target === 'Name' &&
+          edge.rel.reason === 'interface-dispatch',
+      );
+
+      expect(fanout.map((edge) => `${edge.targetLabel}:${edge.targetFilePath}`)).toEqual([
+        'Method:All.cs',
+      ]);
+    } finally {
+      fs.rmSync(root, { recursive: true, force: true });
+    }
+  }, 60000);
+
   it('resolves base.Save() inside UserRecord.Save to BaseEntity.Save (not self)', () => {
     const calls = getRelationships(result, 'CALLS');
     const baseSave = calls.find(