Add comprehensive documentation to PackageExtractor pattern

[Copilot]

Semantic clustering analysis identified duplicate package extraction patterns across npm.go, pip.go, and dependabot.go (85% similarity). While the PackageExtractor abstraction exists and is used correctly, developers continue duplicating the wrapper pattern due to insufficient documentation.

Changes

Package-level documentation (lines 1-95)

• Purpose and benefits section explaining why PackageExtractor eliminates duplication
• Complete examples for npm, pip, go, and uv package managers
• Best practices emphasizing abstraction reuse over reimplementation
• Configuration field explanations with practical guidance

Type and method documentation (lines 101-215)

• Enhanced PackageExtractor type docs with configuration patterns
• Expanded ExtractPackages() method docs with 7-step process
• Field-level examples for CommandNames, RequiredSubcommand, TrimSuffixes
• Multi-line command, flag handling, and shell operator trimming examples

Example

// For pip packages
extractor := PackageExtractor{
    CommandNames:       []string{"pip", "pip3"},
    RequiredSubcommand: "install",
    TrimSuffixes:       "&|;",
}
packages := extractor.ExtractPackages("pip install requests==2.28.0")
// Returns: []string{"requests==2.28.0"}

// For npx packages (no subcommand)
extractor := PackageExtractor{
    CommandNames:       []string{"npx"},
    RequiredSubcommand: "",
    TrimSuffixes:       "&|;",
}

Closes #3823

Original prompt

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This section details on the original issue you should resolve

<issue_title>[task] Add documentation to package_extraction.go explaining PackageExtractor pattern</issue_title>
<issue_description>## Objective
Add comprehensive documentation to pkg/workflow/package_extraction.go explaining the PackageExtractor pattern to prevent code duplication in the future.

Context

The semantic function clustering analysis (issue #3822) identified that the same package extraction pattern is duplicated across multiple files (npm.go, pip.go, dependabot.go). While the PackageExtractor type exists and is used correctly, developers are still duplicating the wrapper pattern instead of following the established abstraction.

This is a Priority 2 refactoring - medium impact focused on code quality.

Current Duplication Pattern

The same pattern appears in 4 places with 85% code similarity:

• pkg/workflow/npm.go:24 - extractNpxFromCommands()
• pkg/workflow/pip.go:39 - extractPipFromCommands() and extractUvFromCommands()
• pkg/workflow/dependabot.go:604 - extractGoFromCommands()

Files to Modify

• Primary: pkg/workflow/package_extraction.go (add documentation)
• Optional: Consider adding a generic example function if helpful

Implementation Steps

1. Review the existing PackageExtractor type in package_extraction.go
2. Add a comprehensive package-level comment explaining:
   • Purpose of the PackageExtractor type
   • How to use it correctly
   • Example usage for different package managers
3. Add function-level documentation to ExtractPackages() method
4. Consider adding a canonical example or pattern to follow
5. Document the configuration fields (CommandNames, RequiredSubcommand, TrimSuffixes)

Documentation Should Include

• Purpose: Explain that PackageExtractor provides a reusable pattern for extracting package names from command strings
• Usage Pattern: Show how to create an extractor with appropriate config
• Examples: Demonstrate npm, pip, and go patterns
• Best Practices: Encourage using this abstraction instead of reimplementing the pattern
• Configuration Details: Document what each field does

Example Documentation Structure

// Package extraction provides utilities for extracting package names from command strings.
//
// The PackageExtractor type provides a reusable pattern for parsing package manager
// commands and extracting package names. This pattern should be used instead of
// reimplementing similar extraction logic.
//
// Example usage for npm:
//   extractor := PackageExtractor{
//       CommandNames:       []string{"npx"},
//       RequiredSubcommand: "",
//       TrimSuffixes:       "&|;",
//   }
//   packages := extractor.ExtractPackages(commands)
//
// Example usage for pip:
//   extractor := PackageExtractor{
//       CommandNames:       []string{"pip", "pip3"},
//       RequiredSubcommand: "install",
//       TrimSuffixes:       "&|;",
//   }
//   packages := extractor.ExtractPackages(commands)

Acceptance Criteria

• Package-level documentation added to package_extraction.go
• PackageExtractor type has comprehensive documentation
• ExtractPackages() method has clear documentation
• At least 2 usage examples are provided in the documentation
• Configuration fields are documented
• Code builds successfully: make build
• Documentation follows Go documentation conventions

Expected Benefits

• Developers understand the existing abstraction
• Reduced likelihood of pattern duplication
• Clearer codebase organization
• Improved maintainability

Estimated Effort

1 hour

Related

Related to #3822
Related to #3822

AI generated by Plan Command for #3822</issue_description>

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

• Fixes [task] Add documentation to package_extraction.go explaining PackageExtractor pattern #3833

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[Copilot]

Pull Request Overview

This PR adds comprehensive documentation to the PackageExtractor pattern in package_extraction.go to prevent future code duplication. The documentation was added in response to semantic analysis that identified 85% similar package extraction patterns being duplicated across npm.go, pip.go, and dependabot.go.

Key Changes:

• Added extensive package-level documentation explaining the purpose, benefits, and usage of PackageExtractor
• Enhanced type and method-level documentation with configuration guidance and examples
• Provided 4 complete examples (npm/npx, pip, go, uv) demonstrating different configuration patterns

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