Extract shared utilities from log parsers to eliminate duplication

[Copilot]

Both Claude and Copilot log parsers contained identical implementations of formatting utilities (formatDuration, formatBashCommand, truncateString, estimateTokens), totaling 138 lines of duplicate code across the two files.

Changes

• New shared module log_parser_shared.cjs containing 4 utility functions with test coverage
• Updated parsers to import from shared module instead of local implementations
• Go embedding updated to include shared module in JavaScript sources map

Example

Before:

// parse_claude_log.cjs
function formatDuration(ms) { /* 15 lines */ }
function formatBashCommand(command) { /* 22 lines */ }
// ... duplicated in parse_copilot_log.cjs

After:

// parse_claude_log.cjs & parse_copilot_log.cjs
const { formatDuration, formatBashCommand, truncateString, estimateTokens } = 
  require("./log_parser_shared.cjs");

Note

formatInitializationSummary was not extracted - Claude returns {markdown, mcpFailures} while Copilot returns string with premium model info.

Original prompt

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This section details on the original issue you should resolve

<issue_title>[duplicate-code] 🔍 Duplicate Code Detected: Log Parser Helper Functions</issue_title>
<issue_description>Analysis of commit 6417277

Assignee: @copilot

Summary

Both Copilot and Claude log parsers reimplement the same helper utilities (duration formatting, command normalization, initialization summaries). The duplication spans dozens of lines and makes the parsers diverge despite identical responsibilities.

Duplication Details

Pattern: Shared helper functions copied across log parsers

• Severity: Medium
• Occurrences: 4 helper functions mirrored in two files (8 instances total)
• Locations:
  • pkg/workflow/js/parse_claude_log.cjs:242
  • pkg/workflow/js/parse_copilot_log.cjs:800
  • pkg/workflow/js/parse_claude_log.cjs:348
  • pkg/workflow/js/parse_copilot_log.cjs:923
  • pkg/workflow/js/parse_claude_log.cjs:520
  • pkg/workflow/js/parse_copilot_log.cjs:1115
  • pkg/workflow/js/parse_claude_log.cjs:555
  • pkg/workflow/js/parse_copilot_log.cjs:1152
• Code Sample:

  function formatDuration(ms) {
    if (!ms || ms <= 0) return "";
    const seconds = Math.round(ms / 1000);
    if (seconds < 60) {
      return `${seconds}s`;
    }
    const minutes = Math.floor(seconds / 60);
    const remainingSeconds = seconds % 60;
    if (remainingSeconds === 0) {
      return `${minutes}m`;
    }
    return `${minutes}m ${remainingSeconds}s`;
  }

Impact Analysis

• Maintainability: Changes to presentation (e.g., new summary fields or formatting tweaks) require editing two large files, risking inconsistency.
• Bug Risk: Fixes applied to one parser may be missed in the other, causing divergent user experiences for different engines.
• Code Bloat: ~60 duplicated lines inflate the scripts and obscure the core parsing logic.

Refactoring Recommendations

1. Extract shared helpers into a common module

   • Move formatting utilities (formatDuration, formatBashCommand, truncateString, initialization summary) into pkg/workflow/js/log_parser_shared.cjs.
   • Estimated effort: Medium; requires updating both parsers to import the helpers and adding shared tests.
   • Benefits: Single source of truth for formatting, easier to evolve.

2. Consider a base parser abstraction

   • Define a common pipeline that handles JSON/JSONL parsing and command summarization, letting engine-specific hooks supply custom behavior.
   • Estimated effort: Medium-high; improves reuse and clarity for future engines.

Implementation Checklist

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

Analysis Metadata

• Analyzed Files: 5
• Detection Method: Serena semantic code analysis
• Commit: 6417277
• Analysis Date: 2025-11-14

AI generated by Duplicate Code Detector</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes [duplicate-code] 🔍 Duplicate Code Detected: Log Parser Helper Functions #3990

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[Copilot]

Pull Request Overview

This PR successfully refactors duplicate code from the Claude and Copilot log parsers by extracting 4 common utility functions into a shared module (log_parser_shared.cjs). The refactoring eliminates approximately 138 lines of duplicate code while maintaining backward compatibility and adding comprehensive test coverage.

Key Changes

• Created a new shared utility module with 4 formatting functions
• Added 19 comprehensive tests covering all edge cases
• Updated both log parsers to use the shared functions via require()
• Properly configured Go embedding for the new module

Reviewed Changes

Copilot reviewed 79 out of 79 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pkg/workflow/js/log_parser_shared.cjs	New shared module with 4 utility functions (formatDuration, formatBashCommand, truncateString, estimateTokens)
pkg/workflow/js/log_parser_shared.test.cjs	Comprehensive test suite with 19 tests covering all edge cases
pkg/workflow/js/parse_claude_log.cjs	Removed duplicate functions, added import from shared module
pkg/workflow/js/parse_copilot_log.cjs	Removed duplicate functions, added import from shared module
pkg/workflow/js/parse_claude_log.test.cjs	Added mock for shared module to support testing
pkg/workflow/js/parse_copilot_log.test.cjs	Added mock for shared module to support testing
pkg/workflow/js.go	Added embedding configuration for the new shared module
.github/workflows/*.lock.yml	Regenerated lock files showing proper bundling of shared functions

The refactoring follows established project patterns, maintains identical functionality, and improves code maintainability by establishing a single source of truth for these formatting utilities. All tests pass and the code is properly formatted and linted.

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