[JosefAschauer]

Problem

A Python class with a parameterized base, class Leaf(Base[str]), has no extends edge. The grammar parses Base[str] in the base list as a subscript, and the base-list reader only took bare identifiers and attributes, so the base was skipped. Everything that follows the class hierarchy misses such a class. This is the Python counterpart of #2856 (Java/TS Store<String>), and the "generic bases" item left open in #2076.

The resolver also reads a class's base list as text (pythonBases in name-matcher.ts, behind module-global and self. dispatch). It looked up Base[str] verbatim and split Pair[str, int] at its inner comma, so current = Leaf() then current.run() did not reach Base.run.

Fix

• Extraction, both arms: a subscript base is unwrapped to its value field before the existing identifier | attribute check, in src/extraction/tree-sitter.ts and in the kernel's codegraph-kernel/src/python.rs. The reference sits at the value's start, the position the plain form had.
• Resolver: pythonBases drops bracketed type arguments (nested ones too) before splitting the list.
• Not linked, as before: Generic[T] / Protocol[T] (outside the project, like their plain forms), a computed base like make()[0], a subscript of a subscript like Base[int][str], and keyword arguments like metaclass=Meta.

Validation

• New __tests__/python-generic-bases.test.ts, run on both arms: wasm (CODEGRAPH_KERNEL=0) and kernel (CODEGRAPH_KERNEL_LANGS=python; skipped when no kernel is staged). 16 tests:

  • Base[str], Base[list[int]], Pair[str, dict[str, int]], a base written over several lines, a mixed list (Mixin, Base[str]), and models.Base[int] all link like their plain forms;
  • a keyword argument, a computed base and Base[int][str] link nothing; Generic[T] links nothing;
  • a module global holding Leaf / Two resolves run to Base::run / Pair::run, with a same-named decoy class in the file.

  Each fix was mutation-checked on its own: disabling the wasm unwrap fails only wasm tests, disabling the kernel unwrap fails only kernel tests, and disabling the pythonBases change fails the module-global test on both arms.

• npx tsc --noEmit: clean. Kernel built with npm run build:kernel.

• Full suite on Linux with the kernel staged: 9281 passed, 4 failed. The failures are environmental and also fail on main:

  • bundle-launcher ×2: no zip binary.
  • cli-sync ×2: the host runs Node 26, which prints the unsupported-Node banner.

• Together with feat(resolution): link Python base methods to their overrides (python-override) #2076, Base.run gets its override link to Leaf.run on both arms.

Follow-ups

• pythonBases reads only the class line, so a base list written over several lines is invisible to it (plain bases too). Fixed in fix(python): a base list wrapped over several lines is read whole #3001, which is stacked on this PR.
• declaredSupertypes' Python branch counts type arguments (str, User) as supertypes, so Repo.save() on class Repo(Base[User]) reached User.save. Fixed in fix(python): a base's type argument is no supertype, so Repo.save() is not User.save #3000, which is independent.

Independent of #2076.

🤖 Generated with Claude Code

https://claude.ai/code/session_018hJjBUPFiLSFBssshFwHzq