Duplicate Code: Codemod frontmatter line-walk/replace pattern

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🔍 Duplicate Code Detected: Codemod frontmatter line-walk/replace pattern

Analysis of commit e750213

Assignee: @copilot

Summary

Multiple codemod implementations repeat the same frontmatter line-walk, block-tracking, replace, and reconstruction pattern. This is duplicated across many pkg/cli/codemod_*.go files and exceeds the duplication threshold.

Duplication Details

Pattern: Frontmatter line walk with block tracking and replacement

• Severity: Medium
• Occurrences: 3+ (seen across many codemods)
• Locations:
  • pkg/cli/codemod_slash_command.go (lines 9-89)
  • pkg/cli/codemod_assign_to_agent.go (lines 12-125)
  • pkg/cli/codemod_permissions.go (lines 12-85)
• Code Sample:

frontmatterLines, markdown, err := parseFrontmatterLines(content)
if err != nil {
	return content, false, err
}

var modified bool
result := make([]string, len(frontmatterLines))

for i, line := range frontmatterLines {
	trimmedLine := strings.TrimSpace(line)
	// block tracking and replacement logic...
	result[i] = line
}

if !modified {
	return content, false, nil
}

newContent := reconstructContent(result, markdown)
return newContent, true, nil

Impact Analysis

• Maintainability: Changes to block-walk behavior (indent handling, comment skipping, etc.) must be made in many files.
• Bug Risk: Inconsistent fixes across codemods can create subtle YAML parsing differences.
• Code Bloat: Repeated 50–100 line loops across codemods increases file size and review overhead.

Refactoring Recommendations

1. Extract a shared helper in pkg/cli/codemod_yaml_utils.go

   • Provide a utility that takes frontmatter lines, a block key, and a line transform callback.
   • Estimated effort: medium (2–4 hours)
   • Benefits: single source of truth for block-walk behavior and indentation handling.

2. Standardize codemod apply flow

   • Build a small scaffold helper like applyFrontmatterLineTransform(content, fn) to handle parse/reconstruct boilerplate.
   • Estimated effort: low to medium (1–2 hours)
   • Benefits: removes repeated parse/reconstruct code and ensures consistent error handling.

Implementation Checklist

• Review duplication findings
• Prioritize refactoring tasks
• Create refactoring plan
• Implement changes
• Update tests
• Verify no functionality broken

Analysis Metadata

• Analyzed Files: 3 core codemod files (pattern appears in many more)
• Detection Method: Serena semantic code analysis
• Commit: e750213
• Analysis Date: February 24, 2026

Generated by Duplicate Code Detector