fix: handle multiline comments in stripComments

[mvtandas]

Summary

Fixes #279

Multiline block comments were not being stripped because the regex used .+? which doesn't match newline characters.

Reproduction

hasESMSyntax(`/* export * */`, { stripComments: true })     // false ✅
hasESMSyntax(`/* \n  export * \n*/`, { stripComments: true }) // true ❌ (should be false)

Fix

- const COMMENT_RE = /\/\*.+?\*\/|\/\/.*(?=[nr])/g;
+ const COMMENT_RE = /\/\*[\s\S]*?\*\/|\/\/.*(?=[nr])/g;

.+? → [\s\S]*? matches any character including newlines (non-greedy).

Tests

Added 3 test cases for multiline block comments. All 201 tests pass.

Summary by CodeRabbit

• Bug Fixes

  • Fixed multi-line comment handling during syntax detection when the stripComments option is enabled, improving accuracy of module syntax classification.

• Tests

  • Added test cases to validate multi-line comment handling in syntax detection.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 1bf96b0c-f49b-4353-a239-aa700077edba

📥 Commits

Reviewing files that changed from the base of the PR and between c5ce4e5 and c294f6d.

📒 Files selected for processing (2)

• src/syntax.ts
• test/syntax.test.ts

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📝 Walkthrough

Walkthrough

Updated the block-comment stripping regex in syntax detection functions to properly match /* ... */ across newlines using [\s\S]*? instead of .+?. This resolves incorrect syntax detection results when stripComments is enabled on multiline commented-out code.

Changes

Cohort / File(s)	Summary
Comment Stripping Regex Fix src/syntax.ts	Modified the block-comment regex pattern from .+? to [\s\S]*? to correctly match multiline /* ... */ comments before syntax detection, affecting hasESMSyntax, hasCJSSyntax, and detectSyntax functions when comment stripping is enabled.
Test Coverage test/syntax.test.ts	Added four test cases to staticTestsWithComments validating multiline and single-line block-comment stripping behavior: bare /* export * */, multiline variants with newlines, and multiline with module.exports, ensuring proper ESM/CJS classification when comments are stripped.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐰 Slashes and stars, now dancing right,
Across the lines, both dark and bright,
Multiline comments meet their fate,
Stripped away to work first-rate! ✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'fix: handle multiline comments in stripComments' accurately describes the primary change: updating the regex to properly handle multiline block comments.
Linked Issues check	✅ Passed	The PR directly addresses issue #279 by replacing .+? with [\\s\\S]*? in the block-comment regex to match newlines, fixing the multiline comment stripping bug described in the issue.
Out of Scope Changes check	✅ Passed	All changes are scoped to fixing the multiline comment stripping issue: regex update in src/syntax.ts and targeted test cases in test/syntax.test.ts with no unrelated modifications.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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