fix(extraction): index TypeScript interface members (#1638) (#1780)

Land upstream #1686 (maxmilian + bompus kernel/CG-28 follow-ups)
onto current main. tree-sitter-typescript interface members
(method_signature / property_signature) were never listed in the
TS extractor, so platform .d.ts APIs had no declaration nodes for
call edges. Mirrors on the Rust kernel path; keeps CG-28 damping
for pure-interface declaration files; filters damped files from
the explore RWR seed set.

Co-authored-by: Colby McHenry <colbymchenry@users.noreply.github.com>

__tests__/explore-declaration-only.test.ts

@@ -96,15 +96,36 @@ describe('CG-28 — a declaration-only file does not outrank implementation on a
     if (testDir && fs.existsSync(testDir)) fs.rmSync(testDir, { recursive: true, force: true });
   });
 
+  /**
+   * Type-level for the purposes of this gate: a type declaration, or a member
+   * an interface declares.
+   *
+   * The second half is not a loosening. Since #1638 a `method_signature` /
+   * `property_signature` is indexed as a `method` / `property` node, so a file
+   * of nothing but interfaces no longer reads as nothing but `interface` kinds
+   * — but a bodiless signature is on the same side of the line as the interface
+   * that owns it, which is exactly how `getAmbientDeclarationPathsAmong` counts
+   * it. What this still catches, and is here to catch, is a `function` or a
+   * `class` creeping into the fixture: that would silently exempt the file and
+   * make every assertion below vacuous.
+   */
+  const isTypeLevel = (n: { id: string; kind: string }, filePath: string): boolean => {
+    if (n.kind === 'interface' || n.kind === 'type_alias') return true;
+    if (n.kind !== 'method' && n.kind !== 'property') return false;
+    const interfaceIds = new Set(
+      cg.getNodesInFile(filePath).filter((x) => x.kind === 'interface').map((x) => x.id),
+    );
+    return cg.getIncomingEdges(n.id)
+      .some((e) => e.kind === 'contains' && interfaceIds.has(e.source));
+  };
+
   describe('fixture shape — if this rots, the gate below means nothing', () => {
     it('holds two declaration-only files that differ only in the banner', () => {
       for (const p of [HANDWRITTEN_DECL, GENERATED_DECL]) {
         const nodes = cg.getNodesInFile(p).filter((n) => n.kind !== 'file' && n.kind !== 'import');
         expect(nodes.length, `${p} declares nothing`).toBeGreaterThan(10);
-        // Every symbol type-level, nothing with a body — the structural test the
-        // penalty keys on. A `function`/`class` creeping in would silently exempt
-        // the file and make every assertion below vacuous.
-        expect(nodes.every((n) => n.kind === 'interface' || n.kind === 'type_alias'), `${p} has a non-type symbol`).toBe(true);
+        // Nothing with a body — the structural test the penalty keys on.
+        expect(nodes.every((n) => isTypeLevel(n, p)), `${p} has a non-type symbol`).toBe(true);
       }
       // Only one of them announces itself, so the CG-25 penalty is the ONLY
       // difference between the two — that is what makes them comparable.
@@ -119,7 +140,7 @@ describe('CG-28 — a declaration-only file does not outrank implementation on a
       // structure of any answer about that code.
       const nodes = cg.getNodesInFile(SHARED_TYPES).filter((n) => n.kind !== 'file' && n.kind !== 'import');
       expect(nodes.length).toBeGreaterThan(0);
-      expect(nodes.every((n) => n.kind === 'interface' || n.kind === 'type_alias')).toBe(true);
+      expect(nodes.every((n) => isTypeLevel(n, SHARED_TYPES))).toBe(true);
       expect(cg.getFile(SHARED_TYPES)?.generated).toBeFalsy();
     });
 
@@ -176,6 +197,23 @@ describe('CG-28 — a declaration-only file does not outrank implementation on a
       expect(isAmbient(SHARED_TYPES)).toBe(false);
       expect(isAmbient(HANDWRITTEN_DECL)).toBe(true);
     });
+
+    it('still flags a shim whose interfaces now contribute method/property nodes', () => {
+      // The silent-failure guard for #1638. Interface members are indexed, so a
+      // pure-interface `.d.ts` no longer holds only `interface` kinds — and the
+      // ambient rule is spelled as "EVERY declared symbol is type-level". Read
+      // literally that stops flagging the moment the extractor improves, and
+      // nothing else fails: the file just quietly ranks undamped again.
+      //
+      // Pinned from both ends on purpose. The `toBeGreaterThan(0)` half is what
+      // keeps the other half honest — assert only the flag and this test would
+      // still pass on an index where the members were never extracted at all,
+      // which is precisely the state it exists to detect a regression FROM.
+      const members = cg.getNodesInFile(HANDWRITTEN_DECL)
+        .filter((n) => n.kind === 'method' || n.kind === 'property');
+      expect(members.length, 'interface members are not indexed — see #1638').toBeGreaterThan(0);
+      expect(cg.ambientDeclarationFilePredicate([HANDWRITTEN_DECL])(HANDWRITTEN_DECL)).toBe(true);
+    });
   });
 
   describe('the counter-case — a query that NAMES a declared type', () => {

__tests__/extraction.test.ts

@@ -566,6 +566,55 @@ interface Hprops {
     expect(refs.some((r) => r.referenceName === 'IOrderField')).toBe(true);
   });
 
+  it('indexes interface members, not just the interface itself', () => {
+    // tree-sitter-typescript spells interface members `method_signature` /
+    // `property_signature`, distinct from the class-member types the extractor
+    // listed, so they were never captured (#1638). Java/C# are unaffected —
+    // their grammars reuse `method_declaration`, already in their methodTypes.
+    // The cost lands on `.d.ts` platform APIs: with no declaration node, call
+    // sites through the interface have nothing to attach an edge to.
+    const code = `
+export interface PlatformApi {
+  fetchPage(id: string): Promise<string>;
+  version: string;
+}
+`;
+    const result = extractFromSource('api.d.ts', code);
+
+    const iface = result.nodes.find((n) => n.kind === 'interface' && n.name === 'PlatformApi');
+    const method = result.nodes.find((n) => n.kind === 'method' && n.name === 'fetchPage');
+    const prop = result.nodes.find((n) => n.kind === 'property' && n.name === 'version');
+    expect(iface).toBeDefined();
+    expect(method).toBeDefined();
+    expect(prop).toBeDefined();
+
+    // Attached to the interface, not merely present. A member the graph holds
+    // but hangs off the file is not a declaration a call edge can be resolved
+    // through, which is the whole point of extracting it.
+    const contained = result.edges
+      .filter((e) => e.kind === 'contains' && e.source === iface!.id)
+      .map((e) => e.target);
+    expect(contained).toContain(method!.id);
+    expect(contained).toContain(prop!.id);
+  });
+
+  it('does not mint a top-level function from a type literal method signature', () => {
+    // The failure mode the class-like guard on `method_signature` exists for
+    // (#1638). `extractMethod` treats a method node with no class-like parent
+    // as a free function — right for `method_definition`, wrong for a bodiless
+    // signature, whose only home outside an interface is a type literal. Those
+    // members are already extracted onto the alias (#359), so without the guard
+    // the file gains a phantom `function stop` beside the real `Handle::stop`.
+    const result = extractFromSource('t.ts', `
+export type Handle = { stop(): void; label: string };
+`);
+
+    const alias = result.nodes.find((n) => n.kind === 'type_alias' && n.name === 'Handle');
+    expect(alias).toBeDefined();
+    expect(result.nodes.find((n) => n.kind === 'method' && n.name === 'stop')).toBeDefined();
+    expect(result.nodes.filter((n) => n.kind === 'function' && n.name === 'stop')).toEqual([]);
+  });
+
   it('should extract type references from interface method signatures', () => {
     const code = `
 import type { IPage } from '../PromoterList';
@@ -899,10 +948,20 @@ export type Names = ['alpha', 'beta'];
 `;
     const result = extractFromSource('noise.ts', code);
 
+    // Since #1638 the fixture's own interfaces legitimately declare `id` / `name`
+    // (`User::id`, `User::name`, `Service::name`), so membership in the name list
+    // no longer implies a leak. What #634 guards is the *source*: a node minted
+    // from a string literal in `Pick<User, 'id'>` or a tuple has no declaring
+    // interface, so exclude anything a `contains` edge ties to one.
+    const ifaceIds = new Set(result.nodes.filter((n) => n.kind === 'interface').map((n) => n.id));
+    const declaredInInterface = new Set(
+      result.edges.filter((e) => e.kind === 'contains' && ifaceIds.has(e.source)).map((e) => e.target)
+    );
     const leaked = result.nodes.filter(
       (n) =>
         (n.kind === 'method' || n.kind === 'property') &&
-        ['id', 'name', 'foo', 'bar', 'alpha', 'beta'].includes(n.name)
+        ['id', 'name', 'foo', 'bar', 'alpha', 'beta'].includes(n.name) &&
+        !declaredInInterface.has(n.id)
     );
     expect(leaked).toEqual([]);
   });

__tests__/object-literal-methods.test.ts

@@ -53,7 +53,11 @@ describe('object-literal method extraction', () => {
 
     // Each action's body was walked: fetchUser references its sibling `reset`,
     // so an in-store calls edge will resolve once the pipeline runs.
-    const fetchUser = result.nodes.find((n) => n.name === 'fetchUser')!;
+    // By KIND as well as name: the fixture's `Store` interface declares a
+    // `fetchUser` too, and since #1638 that signature is a node of its own —
+    // one that appears FIRST in the file, so a name-only lookup finds the
+    // declaration and reads its return type where the action's body was meant.
+    const fetchUser = result.nodes.find((n) => n.kind === 'function' && n.name === 'fetchUser')!;
     const fetchUserRefs = result.unresolvedReferences.filter((r) => r.fromNodeId === fetchUser.id);
     // `get().reset()` keeps its call receiver (#1683): the ref is the chain
     // `get().reset`, which the resolver binds to the store's own `reset`.