Kotlin call-walker: accept both simple_identifier and identifier (#659)

`extract_kotlin` previously emitted zero `calls` edges (and zero
`raw_calls` entries) on the current PyPI grammar. The Kotlin branch
of `walk_calls` only matched node type `simple_identifier`, but
PyPI's `tree_sitter_kotlin` produces `identifier` for the equivalent
plain-identifier node. The `simple_identifier` ↔ `identifier` rename
is a generation gap between tree-sitter-kotlin grammar versions —
older forks (and the JVM `io.github.bonede:tree-sitter-kotlin`
binding) still use `simple_identifier`.

Accept both names so the extractor works across grammar generations.
Also widens `_KOTLIN_CONFIG.name_fallback_child_types` for the same
reason (defensive — currently the `name` field path covers
class/function name resolution, but if that field is dropped in a
future grammar update the fallback would face the same rename).

Tested against `tests/fixtures/sample.kt`: edges go from 6
(file-contains + class-method only) to 10 (adds 4 in-file `calls`
edges resolved by the walker:
  - .get() → .buildRequest() @ L8
  - .post() → .buildRequest() @ L12
  - createClient() → Config @ L21
  - createClient() → HttpClient @ L22).

A new regression test `test_kotlin_emits_in_file_calls` asserts the
four edges so this exact bug can't recur.

Found via graphify-kmp (Kotlin Multiplatform port of graphify) —
its `PythonParityTest` flagged 4 KMP-only edges that Python missed.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

graphify/extract.py

@@ -590,7 +590,11 @@ _KOTLIN_CONFIG = LanguageConfig(
     call_function_field="",
     call_accessor_node_types=frozenset({"navigation_expression"}),
     call_accessor_field="",
-    name_fallback_child_types=("simple_identifier",),
+    # Different tree-sitter-kotlin grammar versions name plain identifier
+    # nodes differently: PyPI's `tree_sitter_kotlin` uses `identifier`,
+    # older forks use `simple_identifier`. Accept both so the extractor
+    # works across grammar generations.
+    name_fallback_child_types=("simple_identifier", "identifier"),
     body_fallback_child_types=("function_body", "class_body"),
     function_boundary_types=frozenset({"function_declaration"}),
     import_handler=_import_kotlin,
@@ -1069,15 +1073,19 @@ def _extract_generic(path: Path, config: LanguageConfig) -> dict:
                                     if sc.type == "simple_identifier":
                                         callee_name = _read_text(sc, source)
             elif config.ts_module == "tree_sitter_kotlin":
-                # Kotlin: first child may be simple_identifier or navigation_expression
+                # Kotlin: first child may be simple_identifier/identifier or
+                # navigation_expression. PyPI's `tree_sitter_kotlin` produces
+                # `identifier` for plain identifier nodes; older grammar
+                # versions (including the JVM `io.github.bonede:tree-sitter-kotlin`
+                # binding) produce `simple_identifier`. Accept both.
                 first = node.children[0] if node.children else None
                 if first:
-                    if first.type == "simple_identifier":
+                    if first.type in ("simple_identifier", "identifier"):
                         callee_name = _read_text(first, source)
                     elif first.type == "navigation_expression":
                         is_member_call = True
                         for child in reversed(first.children):
-                            if child.type == "simple_identifier":
+                            if child.type in ("simple_identifier", "identifier"):
                                 callee_name = _read_text(child, source)
                                 break
             elif config.ts_module == "tree_sitter_scala":

tests/test_languages.py

@@ -188,6 +188,18 @@ def test_kotlin_finds_function():
     r = extract_kotlin(FIXTURES / "sample.kt")
     assert any("createClient" in l for l in _labels(r))
 
+def test_kotlin_emits_in_file_calls():
+    """Regression test for the call-walker `simple_identifier` /
+    `identifier` rename — see graphify-kmp's PythonParityTest."""
+    r = extract_kotlin(FIXTURES / "sample.kt")
+    calls = _calls(r)
+    # In sample.kt: get() and post() both call buildRequest(), and
+    # createClient() invokes Config and HttpClient (constructor calls).
+    assert (".get()", ".buildRequest()") in calls
+    assert (".post()", ".buildRequest()") in calls
+    assert ("createClient()", "Config") in calls
+    assert ("createClient()", "HttpClient") in calls
+
 
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