Function goGrpcStubImplEdges

src/resolution/callback-synthesizer.ts:762–844

* Go gRPC stub → impl bridge. The protoc-gen-go-grpc codegen emits an * `UnimplementedXxxServer` struct in `*_grpc.pb.go` carrying one method * per service RPC; the real handler is a hand-written struct in another * file (`x/bank/keeper/msg_server.go::msgServer.Send` in cosmos-sdk). * Go's struc

(queries: QueryBuilder)

 * stub's source line is the wiring site shown in the trace trail.
 */
function goGrpcStubImplEdges(queries: QueryBuilder): Edge[] {
  const edges: Edge[] = [];
  const seen = new Set<string>();

  const STUB_RE = /^Unimplemented.*Server$/;
  // gRPC internal-helper methods that appear on every Unimplemented*Server;
  // not part of the service contract, so exclude when computing the RPC-method
  // signature used to match impls.
  const isInternalMarker = (n: string) => n.startsWith('mustEmbed') || n === 'testEmbeddedByValue';

  // Methods directly contained by each Go struct, name-only. Built once.
  const methodNamesByStruct = new Map<string, Set<string>>();
  const methodNodesByStruct = new Map<string, Node[]>();
  const goStructs: Node[] = [];
  for (const s of queries.getNodesByKind('struct')) {
    if (s.language !== 'go') continue;
    goStructs.push(s);
    const ms = queries
      .getOutgoingEdges(s.id, ['contains'])
      .map((e) => queries.getNodeById(e.target))
      .filter((n): n is Node => !!n && n.kind === 'method');
    methodNodesByStruct.set(s.id, ms);
    methodNamesByStruct.set(s.id, new Set(ms.map((m) => m.name)));
  }

  for (const stub of goStructs) {
    if (!STUB_RE.test(stub.name)) continue;
    // The stub MUST live in a generated file — that's what tells us this is
    // a protoc-emitted scaffold rather than someone naming a struct
    // `UnimplementedXxxServer` by hand. Without this gate we'd also bridge
    // such hand-written structs and create misleading edges.
    if (!isGeneratedFile(stub.filePath)) continue;

    const stubMethods = (methodNodesByStruct.get(stub.id) ?? []).filter(
      (m) => !isInternalMarker(m.name),
    );
    if (stubMethods.length === 0) continue;
    const stubMethodNames = stubMethods.map((m) => m.name);

    for (const cand of goStructs) {
      if (cand.id === stub.id) continue;
      // Skip generated-file candidates — they're siblings (msgClient,
      // UnsafeMsgServer, …) whose method sets coincidentally match.
      if (isGeneratedFile(cand.filePath)) continue;

      const candNames = methodNamesByStruct.get(cand.id);
      if (!candNames) continue;
      // Subset: every RPC method must exist on the candidate by name.
      // Signature-level match would tighten this further, but name-match
      // alone already gives one-to-one pairing in real codebases because
      // gRPC method-name sets are highly distinctive (Send + MultiSend +
      // UpdateParams + SetSendEnabled is unique to bank's MsgServer).
      if (!stubMethodNames.every((n) => candNames.has(n))) continue;

      const candMethods = methodNodesByStruct.get(cand.id) ?? [];
      let added = 0;
      for (const sm of stubMethods) {
        if (added >= MAX_CALLBACKS_PER_CHANNEL) break;