fix(linter/no-unused-vars): handle non-null assertion in update expressions

[camc314]

Fixes #17280

[camc314]

• fix(linter/no-unused-vars): handle non-null assertion in update expressions #17281 👈 (View in Graphite)
• main

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[camc314]

Merge activity

• Dec 22, 4:48 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Dec 22, 4:53 PM UTC: camc314 added this pull request to the Graphite merge queue.
• Dec 22, 4:59 PM UTC: Merged by the Graphite merge queue.

[Copilot]

Pull request overview

This PR fixes a bug in the no-unused-vars linter rule where TypeScript non-null assertions and type assertions in update expressions were incorrectly causing variables to be flagged as unused.

Key Changes:

• Enhanced the update expression handling to unwrap TypeScript type-related wrappers (non-null assertions, type assertions, etc.) before checking if the argument is a member expression
• Added comprehensive test coverage for non-null assertions (!) and type assertions (as) in both prefix and postfix update expressions

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
crates/oxc_linter/src/rules/eslint/no_unused_vars/usage.rs	Updated logic to unwrap TypeScript wrappers when checking if an update expression argument is a member expression, preventing false positives
crates/oxc_linter/src/rules/eslint/no_unused_vars/tests/oxc.rs	Added 4 test cases covering various combinations of non-null assertions and type assertions with update expressions

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[codspeed-hq]

CodSpeed Performance Report

Merging #17281 will not alter performance

_{Comparing c/12-22-fix_linter_no-unused-vars_handle_non-null_assertion_in_update_expressions (c4be6de) with main (7074353)}

Summary

✅ 4 untouched
⏩ 41 skipped¹

Footnotes

1. 41 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩