[BichengWang]

nblint skips every cell starting with %%, so %%time\nbroken = passes the syntax check even though its Python body cannot compile. There are 22 %%time cells in the current notebooks.

Check %%time bodies using the existing IPython syntax normalization, which preserves the original cell line numbers. Keep other cell magics skipped because their bodies may contain non-Python content. Add offline regression tests and update the rule documentation.

Validation:

• python3 -m unittest tools.test_nblint_syntax tools.test_check_all_links -v — 25 tests pass; the new regressions fail on the original implementation.
• Full nblint_cli.py run over 154 notebooks — zero failures.
• All 22 existing timed cells pass syntax checks and reject an appended broken = in memory.
• python3 tools/check_all_links.py tools/README.md and git diff --check pass.

No notebooks were executed or changed.

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request improves the robustness of the notebook linting process by ensuring that Python code inside %%time cells is subject to the same syntax validation as standard code cells. By explicitly including %%time while continuing to ignore other non-Python cell magics, the tool now catches potential syntax errors that were previously missed, without introducing false positives for non-Python cell types.

Highlights

• Enhanced Syntax Checking: Updated the nblint tool to include %%time cells in Python syntax validation, ensuring that code within these timed cells is correctly parsed and checked for errors.
• Regression Testing: Added a new test suite, tools/test_nblint_syntax.py, to verify that timed cells are correctly validated while other cell magics remain appropriately skipped.
• Documentation Update: Updated the lint rules reference in tools/README.md to reflect the change in how %%time cells are handled during syntax checks.

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[gemini-code-assist]

Code Review

This pull request updates the notebook linter (nblint) to parse and validate the syntax of Python code cells that use the %%time cell magic, while continuing to skip other non-Python cell magics. It also introduces a comprehensive test suite in tools/test_nblint_syntax.py to verify this behavior. The feedback suggests optimizing the check for %%time by using src.split(maxsplit=1)[0] instead of src.split()[0] to avoid splitting the entire content of large notebook cells, which improves performance.

[kkorpal]

Thanks, nice catch. Verified locally: 25/25 tests pass, the new tests fail against the current syntax.py, all 22 %%time cells in the repo pass as-is and each one is flagged if I append broken =, and a full nblint run over all notebooks is unchanged (0 failures, same warnings as main). LGTM.

Same note as on #1432: tools/test_nblint_syntax.py isn't run by CI yet leaving that to @Giom-V.

[BichengWang]

Added the syntax tests to the notebook workflow and enabled it for tool and workflow changes. All 25 syntax and link-checker tests pass locally.

[BichengWang]

@Giom-V, the syntax tests now run in CI and all checks are green. Does the CI wiring look good to you?

[Giom-V]

Thanks for the fix @BichengWang! I removed the unit tests and CI step from this PR so we don't have to maintain a separate unit test suite for internal helper scripts. Merging!