Eliminates panic-prone error handling, removes platform-specific commands, and establishes modular code organization.

Error Handling: Result<T,E> Pattern

Before:

io::stdin().read_line(&mut project_name)
    .expect("Generic error message that doesn't help you at all 🤣");
Command::new("bun").arg("create").output()
    .expect("Failed to execute bun create command 😭...");

After:

// Custom error types with proper propagation
pub enum BunCliError {
    Io(io::Error),
    CommandFailed { command: String, message: String },
    InvalidProjectName(String),
    BunNotInstalled,
    // ...
}

pub fn run() -> Result<()> {
    let project_name = Self::read_project_name()?;
    let generator = ProjectGenerator::new(config);
    generator.generate()?;
    Ok(())
}

All functions return Result<T, E>. Zero .expect() or panic! calls in production code.

Filesystem: Cross-Platform Operations

• Removed: Windows-specific xcopy via cmd /C
• Added: std::fs-based recursive copy that checks file metadata (size, mtime) before writing
• Reduces redundant writes; works on Windows/Linux/macOS

Architecture: Module Separation

src/
├── main.rs (9 lines) - Entry point only
├── lib.rs - Public API
├── cli.rs - User interaction
├── error.rs - Error types
└── generator.rs - Business logic + tests

Separates CLI from generation logic, enables library usage and unit testing.

Testing

Added validation tests for project name constraints (empty, invalid chars). All clippy warnings resolved.

💡 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.