feat(pattern): support alternation syntax in command name position

[fohte]

Why

• Allow | (alternation) syntax in the command name position of patterns
  • Commands with aliases (e.g., ast-grep and sg) currently require duplicating the same rule on two separate lines

What

• Accept alternation syntax in the command name position so that a rule applies when any of the specified command names match

---

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.82%. Comparing base (9882e01) to head (532cccf).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #91      +/-   ##
==========================================
+ Coverage   88.78%   88.82%   +0.03%     
==========================================
  Files          29       29              
  Lines        5705     5707       +2     
==========================================
+ Hits         5065     5069       +4     
+ Misses        640      638       -2     

Flag	Coverage Δ
Linux	88.64% <100.00%> (+0.03%)	⬆️
macOS	90.88% <100.00%> (+<0.01%)	⬆️

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[gemini-code-assist]

Summary of Changes

Hello @fohte, 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 enhances the pattern matching capabilities by introducing support for alternation syntax in the command name position. This allows users to define a single pattern that can match multiple command aliases, significantly reducing redundancy and simplifying pattern definitions for tools with aliased commands.

Highlights

• New CommandPattern::Alternation variant: Introduced a new Alternation variant to the CommandPattern enum, allowing patterns to match against multiple command names using | syntax (e.g., ast-grep|sg).
• Updated pattern matching logic: Modified the matches method for CommandPattern to correctly evaluate the new Alternation variant, checking if the given command matches any of the specified alternatives.
• Enhanced pattern parsing: Updated the parse function to recognize and correctly construct CommandPattern::Alternation when the input pattern includes the | syntax in the command name position.
• Comprehensive test coverage: Added new rstest test cases to validate the parsing of command alternations with various numbers of aliases and to ensure the matches logic functions as expected for these new patterns.

Changelog

• src/rules/pattern_parser.rs
  • Added Alternation variant to CommandPattern enum to represent multiple command names.
  • Updated CommandPattern::matches to support matching against Alternation variants.
  • Modified parse function to handle LexToken::Alternation and create CommandPattern::Alternation.
  • Included new test cases for parsing and matching command alternation patterns.

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[gemini-code-assist]

Code Review

This pull request introduces support for alternation syntax in the command name position of patterns, allowing rules to apply to multiple command aliases (e.g., "ast-grep|sg"). The changes include adding a new Alternation variant to the CommandPattern enum, updating the matches logic, and integrating it into the parse function. New parameterized tests have been added to cover this functionality, ensuring correctness and adherence to the testing style guide by naming #[case] variants and using rstest effectively. The implementation is clean and directly addresses the stated goal of improving pattern flexibility.

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 3 additional findings.