Add Homebrew Utilities Migration with Bash and Comprehensive Testing

[ooloth]

💪 What

Homebrew Utilities Migration: Complete migration of Homebrew functionality from zsh to bash following the established bash migration pattern.

Files Changed

• lib/homebrew-utils.bash - Core Homebrew utility functions with zero shellcheck warnings
• test/install/test-homebrew-utils.bats - Comprehensive unit tests (9 test cases, all passing)
• bin/install/homebrew.bash - Installation script using shared utilities

New Functionality

• get_homebrew_prefix() - Architecture-specific Homebrew prefix detection (Apple Silicon vs Intel)
• ensure_homebrew_in_path() - Smart PATH management without duplication
• is_homebrew_package_installed() - Package installation checking
• detect_homebrew(), get_homebrew_version(), validate_homebrew_installation() - Existing functions migrated

🤔 Why

Phase 1 of bash migration project: Extract shared Homebrew utilities that are reused across multiple installation scripts, following the successful patterns established in GitHub and SSH utility migrations.

Benefits demonstrated:

• Industry-standard tooling - Shellcheck compliance and bats testing
• Comprehensive test coverage - All functions tested with edge cases
• Architecture awareness - Proper Apple Silicon vs Intel detection
• Zero regressions - Maintains all existing functionality while improving code quality

👀 Usage

Installation script usage:

# Install Homebrew and Brewfile packages
./bin/install/homebrew.bash install

# Update existing Homebrew installation
./bin/install/homebrew.bash update

# Install only Brewfile packages
./bin/install/homebrew.bash packages

Utility functions for other scripts:

source "$DOTFILES_ROOT/lib/homebrew-utils.bash"

if detect_homebrew; then
    ensure_homebrew_in_path
    if is_homebrew_package_installed "git"; then
        echo "Git is available via Homebrew"
    fi
fi

👩‍🔬 How to validate

Run all unit tests:

./test/run-tests.zsh test-homebrew-utils
# OR
bats test/install/test-homebrew-utils.bats

Test installation script:

# Dry run to see what would happen
DRY_RUN=true ./bin/install/homebrew.bash install

# Test architecture detection
./lib/homebrew-utils.bash
get_homebrew_prefix  # Should return /opt/homebrew or /usr/local

Verify shellcheck compliance:

shellcheck lib/homebrew-utils.bash
shellcheck bin/install/homebrew.bash

All tests pass, zero shellcheck warnings, and maintains feature parity with original zsh implementation.

🔗 Related links

• Bash Migration Task Documentation - Project roadmap and architecture
• PR #13: GitHub Installation Testing - Established migration pattern
• PR #15: SSH Installation Testing - Previous successful migration