Create common utility packages to eliminate duplicate functions

[Copilot]

The codebase had 15+ duplicate utility function implementations scattered across pkg/cli, creating maintenance burden and inconsistency.

Changes

Created 4 utility packages:

• pkg/sliceutil - Contains, ContainsAny, ContainsIgnoreCase
• pkg/stringutil - Truncate, NormalizeWhitespace, SanitizeErrorMessage
• pkg/repoutil - SplitRepoSlug, ParseGitHubURL, SanitizeForFilename
• pkg/mathutil - Min, Max

Migrated 17 files from local implementations to shared packages, removing ~150 lines of duplicate code.

Added comprehensive test coverage:

• Added 70+ new test cases covering edge cases, unicode handling, and performance benchmarks
• Achieved 100% code coverage across all 4 utility packages
• Tests include: large data handling, boundary conditions, real-world examples, commutative/identity properties
• Added performance benchmarks for all utility functions

Example

Before:

// pkg/cli/deps_outdated.go
func truncate(s string, maxLen int) string {
    if len(s) <= maxLen { return s }
    return s[:maxLen-3] + "..."
}

// pkg/cli/audit_report_render.go  
func truncateString(s string, maxLen int) string {
    if len(s) <= maxLen { return s }
    if maxLen <= 3 { return s[:maxLen] }
    return s[:maxLen-3] + "..."
}

After:

import "github.com/githubnext/gh-aw/pkg/stringutil"

// Both files now use:
stringutil.Truncate(s, maxLen)

All packages include comprehensive tests with 100% coverage. Backward compatibility maintained via wrapper functions where needed (e.g., pkg/cli/repo.SplitRepoSlug).

Testing

• ✅ All utility packages: 100% code coverage
• ✅ 70+ test cases including edge cases and benchmarks
• ✅ make fmt - passed
• ✅ make lint - passed (0 issues)
• ✅ All tests passing

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[plan] Create common utility packages to eliminate duplicate functions</issue_title>
<issue_description>## Objective

Create standardized utility packages (sliceutil, stringutil, repoutil, mathutil) and migrate 15+ duplicate function implementations from pkg/cli to these shared packages.

Context

Currently, the codebase has duplicate implementations of common utilities scattered across pkg/cli:

• 5 different "contains" functions
• 2 truncate functions
• 4 sanitization functions
• 4 repository parsing implementations
• Multiple generic utilities (min, normalize, etc.)

This creates maintenance burden and inconsistency. Consolidating into shared packages will provide a single source of truth.

Implementation Steps

1. Create pkg/sliceutil/sliceutil.go:

   • Contains(slice []string, item string) bool
   • ContainsAny(s string, substrings ...string) bool
   • ContainsIgnoreCase(s, substr string) bool

2. Create pkg/stringutil/stringutil.go:

   • Truncate(s string, maxLen int) string (consolidate 2 implementations)
   • NormalizeWhitespace(content string) string (move from update_merge.go)

3. Create pkg/stringutil/sanitize.go:

   • SanitizeForFilename(s string) string
   • SanitizeErrorMessage(message string) string
   • CleanIdentifier(s string) string

4. Create pkg/repoutil/repoutil.go:

   • SplitRepoSlug(slug string) (owner, repo string, err error) (canonical version)
   • ParseGitHubURL(url string) (owner, repo string, err error)
   • SanitizeForFilename(slug string) string

5. Create pkg/mathutil/mathutil.go:

   • Min(a, b int) int
   • Max(a, b int) int

6. Update all imports in affected files across pkg/cli

7. Remove duplicate implementations after migration

Files to Modify

Create:

• pkg/sliceutil/sliceutil.go
• pkg/sliceutil/sliceutil_test.go
• pkg/stringutil/stringutil.go
• pkg/stringutil/stringutil_test.go
• pkg/stringutil/sanitize.go
• pkg/stringutil/sanitize_test.go
• pkg/repoutil/repoutil.go
• pkg/repoutil/repoutil_test.go
• pkg/mathutil/mathutil.go
• pkg/mathutil/mathutil_test.go

Update imports in:

• pkg/cli/logs_utils.go
• pkg/cli/docker_images_test.go
• pkg/cli/commands_utils_test.go
• pkg/cli/mcp_schema_test.go
• pkg/cli/mcp_registry_improvements_test.go
• pkg/cli/deps_outdated.go
• pkg/cli/audit_report_render.go
• pkg/cli/trial_command.go
• pkg/cli/compile_config.go
• pkg/cli/mcp_registry.go
• pkg/cli/repo.go
• pkg/cli/tokens_bootstrap.go
• pkg/cli/git.go
• pkg/cli/exec.go
• pkg/cli/update_merge.go
• pkg/cli/spec.go
• pkg/cli/copilot_instructions_test.go

Acceptance Criteria

• All utility packages created with comprehensive tests
• All duplicate implementations replaced with imports to new packages
• All existing tests pass (run make test)
• No new linter warnings (run make lint)
• Code formatted correctly (run make fmt)

Testing

Run full test suite after changes:

make fmt
make lint
make test

Estimated Effort

6-8 hours
Related to #7778

AI generated by Plan Command for #7778

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

• Fixes [plan] Create common utility packages to eliminate duplicate functions #7796

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[pelikhan]

@copilpt merge main and add more tests

[pelikhan]

@copilot merge main and add more tests

[Copilot]

@copilot merge main and add more tests

Completed in bd2912b:

• Merged main branch successfully
• Added 70+ comprehensive test cases across all utility packages
• All packages now have 100% code coverage
• Added edge case tests, unicode handling, performance benchmarks
• All tests passing, code formatted and linted