fix(shell): avoid false fuzzy matches in branch names

[tobiase]

Summary

• parse shell wrapper flags exactly instead of substring-matching -f
• keep branch names containing -f on the normal non-interactive path
• cover the s alias and explicit fuzzy mode with integration tests

Repro

wt s 2026-03-04-form-tracking-debug-floating-report printed a raw CD:/... line instead of switching, because the wrapper treated the branch name as if -f had been passed.

Testing

• go test ./test/integration -run 'TestShellWrapperScript|TestShellWrapper'
• go test ./...
• make install-local

[claude]

Claude finished @tobiase's task —— View job

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PR Review: fix(shell): avoid false fuzzy matches in branch names

Todo List:

• Read and analyze cmd/wt/main.go changes
• Read and analyze test/integration/shell_test.go changes
• Review implementation approach and logic
• Assess test coverage adequacy
• Check for potential bugs or edge cases
• Evaluate security and performance implications
• Provide final review feedback

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Summary

This PR fixes a critical bug where branch names containing -f were incorrectly parsed as fuzzy flags, causing the shell wrapper to malfunction. The solution implements exact flag parsing instead of substring matching.

✅ Code Quality & Best Practices

Excellent implementation approach:

• Exact Flag Parsing: The new logic in cmd/wt/main.go:61-80 properly parses shell arguments using a case statement rather than substring matching
• Clear Logic Flow: The argument parsing separates flags (--fuzzy|-f, -*) from positional arguments systematically
• Consistent Style: Follows existing Go and shell conventions in the codebase

Good separation of concerns:

• Flag parsing logic is isolated and well-commented
• Maintains existing shell wrapper architecture
• Preserves all existing functionality while fixing the bug

✅ Bug Analysis & Fix Quality

Root cause correctly identified:

• The issue was substring matching treating branch names like 2026-03-04-form-tracking-debug-floating-report as containing the -f flag
• The fix addresses this by parsing arguments positionally rather than searching for substrings

Robust solution:

• Handles all flag variations (--fuzzy, -f)
• Correctly ignores other dash-prefixed arguments (-*)
• Preserves navigation target extraction logic

✅ Test Coverage & Integration Tests

Comprehensive test scenarios in test/integration/shell_test.go:

New test cases (lines 224-235):

{
    name:         "branch names containing -f do not trigger fuzzy mode",
    command:      "wt s 2026-03-04-form-tracking-debug-floating-report", 
    checkScript:  `pwd`,
    expectOutput: "/test/branch-with-f",
    rejectOutput: "CD:/test/branch-with-f", // Ensures no raw output
}

Excellent test design:

• Tests the exact reproduction case from the issue
• Verifies both positive (correct CD behavior) and negative (no raw output) conditions
• Includes the s alias coverage mentioned in the PR description
• Uses mock binary pattern for reliable, fast testing

Mock binary approach (lines 310-368):

• Creates a controlled test environment
• Tests shell wrapper integration without filesystem dependencies
• Covers error conditions and different output types

✅ Security & Performance

Security considerations:

• No security vulnerabilities introduced
• Shell command injection risks remain properly mitigated by existing %q quoting
• EXEC command security note preserved (lines 452-454)

Performance impact:

• Minimal performance overhead from the new parsing loop
• More efficient than previous substring matching approach
• No regression in shell wrapper responsiveness

✅ Edge Cases & Robustness

Well-handled edge cases:

• Empty arguments
• Multiple flags in combination
• Branch names with various dash patterns
• Mix of flags and positional arguments

Potential considerations (minor):

1. Long argument lists: The parsing loop is O(n) but this is negligible for typical CLI usage
2. Unusual branch names: Should handle branches with spaces, special characters correctly due to shell quoting

✅ Documentation & Comments

Good inline documentation:

• Clear comment on line 61: "Parse args exactly so branch names like 'feature/foo-form' do not trigger fuzzy mode"
• Shell wrapper logic is well-documented
• Test case names are descriptive

🎯 Recommendations

1. Consider adding one more test case for branches with multiple dashes: feature-foo-form-bar-f-something
2. The implementation is ready to merge - this is a solid, well-tested fix

Final Assessment

This is an excellent PR that:

• ✅ Correctly identifies and fixes the root cause
• ✅ Implements a clean, maintainable solution
• ✅ Includes comprehensive integration tests
• ✅ Maintains backward compatibility
• ✅ Has no security or performance regressions
• ✅ Follows project coding standards

Recommendation: APPROVE ✅

The fix is production-ready and significantly improves the reliability of the shell wrapper for users with dash-containing branch names.

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