feat(pattern): support multi-word alternation syntax in command position

[fohte]

Why

• Patterns like "npx prettier"|"bunx prettier"|prettier * should allow multi-word alternatives containing spaces
  • Covering npx prettier, bunx prettier, and prettier under a single rule currently requires three separate rules

What

• Expand quoted multi-word alternation into multiple independent Pattern instances at parse time, enabling matching without changes to the existing matcher

---

[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 significantly improves the flexibility of pattern matching by introducing support for multi-word alternations in the command position. This allows users to define a single, more powerful rule that can match several variations of a command, including those with multiple words or different prefixes, without altering the core matching logic. The change simplifies rule definition and makes the pattern language more robust for complex command structures.

Highlights

• Multi-word Alternation Syntax: Introduced support for multi-word alternation in the command position, allowing patterns like "npx prettier"|prettier * to be expressed as a single rule. This enhances pattern expressiveness and reduces the need for multiple rules to cover variations of a command.
• Lexer Enhancements: The pattern lexer was updated to recognize and tokenize multi-word alternations, distinguishing them from single-word alternations and literals. This includes handling quoted multi-word segments and combining them with bare-word alternatives.
• Parser Expansion: A new parse_multi function was added to the pattern parser. This function expands multi-word alternation tokens into multiple distinct Pattern instances at parse time, allowing the existing matcher to process them without modification.
• Rule Engine Integration: The rule engine was modified to utilize the new parse_multi function, enabling it to correctly evaluate rules containing multi-word alternations by iterating through the expanded patterns until a match is found.
• Comprehensive Testing: Extensive unit and integration tests were added to cover various scenarios of multi-word alternation, including mixed quoted and bare-word alternatives, error cases, and backward compatibility with existing single-word alternations.

Changelog

• src/rules/pattern_lexer.rs
  • Added MultiWordAlternation variant to LexToken enum.
  • Modified tokenize function to detect and parse multi-word alternations, especially those involving quoted strings.
  • Introduced consume_alternation_continuation to handle subsequent alternatives in a multi-word sequence.
  • Added classify_multi_word_alternation to determine if a set of alternatives should be MultiWordAlternation or Alternation.
  • Updated is_word_boundary to include quotes as word boundaries.
  • Added new unit tests for multi-word alternation parsing and error handling.
• src/rules/pattern_matcher.rs
  • Added new test cases to verify correct matching behavior for multi-word alternations.
  • Included tests for backward compatibility with existing single-word alternations.
• src/rules/pattern_parser.rs
  • Introduced parse_multi function to handle patterns that may contain multi-word alternations, returning a vector of Pattern instances.
  • Modified build_pattern_tokens and lex_to_pattern_value to explicitly disallow MultiWordAlternation tokens outside of the command position.
  • Added unit tests for the parse_multi function, demonstrating its expansion capabilities.
• src/rules/rule_engine.rs
  • Updated evaluate_command_inner to use parse_multi instead of parse for pattern parsing, allowing it to process expanded patterns.
  • Modified try_unwrap_wrapper to also use parse_multi when evaluating wrapper patterns, ensuring consistent behavior.
• tests/integration/config_to_rule_evaluation.rs
  • Added integration tests to confirm that multi-word alternation rules defined in YAML configurations are correctly evaluated.

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[codecov]

Codecov Report

❌ Patch coverage is 93.25843% with 12 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.07%. Comparing base (6fabb81) to head (ae5a01b).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
src/rules/pattern_lexer.rs	94.00%	6 Missing ⚠️
src/rules/pattern_parser.rs	81.81%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #94      +/-   ##
==========================================
+ Coverage   89.00%   89.07%   +0.06%     
==========================================
  Files          29       29              
  Lines        5821     5966     +145     
==========================================
+ Hits         5181     5314     +133     
- Misses        640      652      +12     

Flag	Coverage Δ
Linux	88.90% <93.25%> (+0.07%)	⬆️
macOS	91.08% <93.25%> (+0.01%)	⬆️

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