[PR] Raise a clear error for unknown TypedDict fields in extract_fields [hamilton]

["breken-ai (via GitHub)" <gi...@apache.org>]

breken-ai opened a new pull request, #1733:
URL: https://github.com/apache/hamilton/pull/1733

   When `@extract_fields` gets a list of field names and the function returns a `TypedDict`, a name that is not in the `TypedDict` is recorded in `errors`. It is then looked up anyway on the next line. Users get a bare `KeyError` at graph-build time instead of the `InvalidDecoratorException` that lists the invalid fields.
   
   ```python
   class MyDict(TypedDict):
       test: int
   
   @extract_fields(["test", "tset"])
   def d() -> MyDict: ...
   
   # on main: KeyError: 'tset'
   # expected: InvalidDecoratorException: ... The following fields were not valid:
   #           ["tset is not a field in the `TypedDict` ..."]
   ```
   
   The dict form (`extract_fields({"tset": int})`) already reports this properly, because that branch `continue`s after recording the error.
   
   ## Changes
   
   - `hamilton/function_modifiers/expanders.py`: in `_determine_fields_to_extract`, `continue` after recording an unknown field, matching the dict branch just below it.
   - `tests/function_modifiers/test_expanders.py`: one more case in `test_extract_fields_invalid_annotations_for_inferred_types`, `("MyDict", (["test", "not_a_field"]))`.
   
   ## How I tested this
   
   - New case on unmodified `main` (`661aa888`): fails with `KeyError: 'not_a_field'`.
   - With the fix, it passes (the expected `InvalidDecoratorException` is raised).
   - `pytest tests/function_modifiers tests/test_function_modifiers.py tests/test_end_to_end.py tests/test_hamilton_driver.py tests/test_async_driver.py`: 528 passed.
   - `ruff check` and `ruff format --check` (0.15.14) are clean. `git diff --check` is clean.
   
   ## Notes
   
   This was introduced with the list-of-names support for `TypedDict` in d601a92f (2025-07).
   
   ## Checklist
   
   - [x] PR has an informative and human-readable title (this will be pulled into the release notes)
   - [x] Changes are limited to a single goal (no scope creep)
   - [x] Code passed the pre-commit check & code is left cleaner/nicer than when first encountered.
   - [x] Any _change_ in functionality is tested
   - [ ] New functions are documented (with a description, list of inputs, and expected output) — no new functions
   - [ ] Placeholder code is flagged / future TODOs are captured in comments — none added
   - [ ] Project documentation has been updated if adding/changing functionality — no documented behavior changes; this makes the code match the existing docs
   
   ---
   
   **AI disclosure (per the [ASF Generative Tooling guidance](https://www.apache.org/legal/generative-tooling.html)):** this change was written with an AI coding tool (Claude Code, Claude Opus 5.5) working through the `breken-ai` account. The tool found the bug, wrote the fix and the test, and wrote this description. The commit carries a `Generated-by:` trailer. The diff is a small original change to existing Hamilton code and includes no third-party material. The red/green runs above are real and can be re-run from the diff. If you would rather not take AI-assisted contributions here, say so and I will close this.
   


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Re: [PR] Raise a clear error for unknown TypedDict fields in extract_fields [hamilton]

["skrawcz (via GitHub)" <gi...@apache.org>]

skrawcz merged PR #1733:
URL: https://github.com/apache/hamilton/pull/1733


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