fix(ts): resolve new_expression constructor calls (#3116)

A TypeScript/JavaScript `new Foo()` emitted no edge. Fall back to the new_expression's
constructor child in the generic callee branch, so it emits a calls edge to the constructed
class (member, chained, and generic forms), reusing the existing built-in-global guard so
new Map()/new Promise() are not fabricated. Consistent with the C# object-creation handling
(#2997).

graphify/extractors/engine.py

@@ -5388,8 +5388,10 @@ def _extract_generic(
                         # unique-but-wrong one (#3078).
                         member_receiver = _ruby_const_full_name(recv, source) or None
             else:
-                # Generic: get callee from call_function_field
+                # Generic: get callee from call_function_field (or constructor on new_expression)
                 func_node = node.child_by_field_name(config.call_function_field) if config.call_function_field else None
+                if func_node is None and node.type == "new_expression":
+                    func_node = node.child_by_field_name("constructor")
                 if func_node:
                     if func_node.type == "identifier":
                         callee_name = _read_text(func_node, source)

tests/test_ts_new_expression_calls.py

@@ -0,0 +1,100 @@
+"""TS/JS/TSX `new Foo(...)` constructor calls emit `calls` edges (#3116).
+
+In tree-sitter JS/TS, `new_expression` exposes its callee under the `constructor`
+field rather than `function`. The generic path in `walk_calls` previously queried
+only `call_function_field="function"`, dropping constructor calls.
+"""
+from __future__ import annotations
+
+from pathlib import Path
+
+from graphify.extract import extract, extract_js
+
+
+def _calls(tmp_path: Path, files: dict[str, str]):
+    for name, body in files.items():
+        p = tmp_path / name
+        p.parent.mkdir(parents=True, exist_ok=True)
+        p.write_text(body, encoding="utf-8")
+    r = extract([tmp_path / n for n in files],
+                cache_root=tmp_path / "graphify-out", parallel=False)
+    lbl = {n["id"]: n["label"] for n in r["nodes"]}
+    calls = {(lbl.get(e["source"]), lbl.get(e["target"])) for e in r["edges"]
+             if e["relation"] == "calls"}
+    return calls, r
+
+
+def test_ts_new_expression_emits_calls_edge_in_file(tmp_path: Path):
+    calls, _ = _calls(tmp_path, {
+        "main.ts": (
+            "class Foo {\n"
+            "  constructor(x: number) {}\n"
+            "}\n"
+            "function caller() {\n"
+            "  const x = new Foo(1);\n"
+            "}\n"
+        )
+    })
+    assert any(s == "caller()" and t == "Foo" for s, t in calls)
+
+
+def test_ts_new_expression_resolves_cross_file(tmp_path: Path):
+    calls, r = _calls(tmp_path, {
+        "foo.ts": "export class Foo {}\n",
+        "caller.ts": (
+            'import { Foo } from "./foo";\n'
+            "export function caller() {\n"
+            "  const x = new Foo();\n"
+            "}\n"
+        ),
+    })
+    assert any(s == "caller()" and t == "Foo" for s, t in calls)
+    cross_edges = [
+        e for e in r["edges"]
+        if e["relation"] == "calls"
+        and "caller" in e["source"]
+        and "foo" in e["target"].lower()
+    ]
+    assert len(cross_edges) == 1
+
+
+def test_js_new_expression_emits_calls_edge(tmp_path: Path):
+    calls, _ = _calls(tmp_path, {
+        "app.js": (
+            "class Service {}\n"
+            "function init() {\n"
+            "  const s = new Service();\n"
+            "}\n"
+        )
+    })
+    assert any(s == "init()" and t == "Service" for s, t in calls)
+
+
+def test_tsx_new_expression_emits_calls_edge(tmp_path: Path):
+    calls, _ = _calls(tmp_path, {
+        "comp.tsx": (
+            "class Widget {}\n"
+            "function App() {\n"
+            "  const w = new Widget();\n"
+            "  return <div>{w}</div>;\n"
+            "}\n"
+        )
+    })
+    assert any(s == "App()" and t == "Widget" for s, t in calls)
+
+
+def test_ts_member_new_expression_raw_calls(tmp_path: Path):
+    file_path = tmp_path / "member.ts"
+    file_path.write_text(
+        "function caller() {\n"
+        "  const s = new pkg.Foo();\n"
+        "}\n",
+        encoding="utf-8",
+    )
+    r = extract_js(file_path)
+    assert any(
+        rc["callee"] == "Foo"
+        and rc.get("is_member_call") is True
+        and rc.get("receiver") == "pkg"
+        for rc in r.get("raw_calls", [])
+    )