fix(parser): retain enclosing context for calls in anonymous callbacks (JS/TS) (#1570) - #1629

Description

Fixes #1570

When a function call is located inside an anonymous callback (such as arrow functions or function expressions passed to setTimeout, .then, app.use, event listeners, array methods, etc.), _get_parent_context in the TypeScript and JavaScript parsers previously stopped its AST traversal at the anonymous function node. Because anonymous functions lack an identifier name, name_node resolved to None, causing _get_parent_context to immediately return (None, curr.type, line).

Consequently, the call was attributed to a nameless caller, dropping the (Function)-[:CALLS]->(...) edge from the call graph and causing find_callers to miss the enclosing function.

Changes Made

• TypeScript & JavaScript AST Context Traversal (typescript.py, javascript.py):
  • Updated _get_parent_context to continue ascending parent AST nodes until a named enclosing scope (function_declaration, class_declaration, method_definition, or named/assigned arrow_function/function_expression) is found.
  • Added support for resolving names from variable declarators, member assignment expressions (obj.fn = ...), object pairs ({ fn: ... }), and class field definitions (field_definition, public_field_definition, property_definition).
  • TSX (typescriptjsx.py) automatically inherits the fix.
• Consistency Across Parsers (cpp.py, csharp.py, go.py, lua.py):
  • Ensured _get_parent_context only returns when a name is resolved and continues walking up otherwise.
• Tests Added:
  • tests/unit/parsers/test_typescript_parser.py: Unit tests for single- and multi-level nested callbacks and top-level anonymous IIFEs.
  • tests/unit/parsers/test_javascript_parser.py: Unit tests for callback functions and class method callbacks in JS.
  • tests/unit/tools/test_cross_lang_call_resolution_patterns.py: End-to-end call graph resolution tests verifying that build_function_call_groups outputs CALLS edges from the enclosing named caller function in TS, TSX, and JS.

Verification

• Ran parser unit tests and call resolution test suites:

  pytest tests/unit/parsers/test_typescript_parser.py tests/unit/parsers/test_javascript_parser.py tests/unit/tools/test_cross_lang_call_resolution_patterns.py