cli-ux-patterns

# CLI UX Patterns Skill

Best practices and patterns for creating delightful command-line user experiences.

## Error Message Patterns

### The Three Parts of Good Error Messages

1. **What went wrong** - Clear description of the error
2. **Why it matters** - Context about the operation
3. **How to fix it** - Actionable suggestions

```rust
bail!(
    "Failed to read config file: {}\n\n\
     The application needs a valid configuration to start.\n\n\
     To fix this:\n\
     1. Create a config file: myapp init\n\
     2. Or specify a different path: --config /path/to/config.toml\n\
     3. Check file permissions: ls -l {}",
    path.display(),
    path.display()
);
```

### Using miette for Rich Diagnostics

```rust
#[derive(Error, Debug, Diagnostic)]
#[error("Configuration error")]
#[diagnostic(
    code(config::invalid),
    url("https://docs.example.com/config"),
    help("Check the syntax of your configuration file")
)]
struct ConfigError {
    #[source_code]
    src: String,

    #[label("invalid value here")]
    span: SourceSpan,
}
```

## Color Usage Patterns

### Semantic Colors

- **Red** - Errors, failures, destructive actions
- **Yellow** - Warnings, cautions
- **Green** - Success, completion, safe operations
- **Blue** - Information, hints, links
- **Cyan** - Highlights, emphasis
- **Dim/Gray** - Less important info, metadata

```rust
use owo_colors::OwoColorize;

// Status indicators with colors
println!("{} Build succeeded", "✓".green().bold());
println!("{} Warning: using default", "⚠".yellow().bold());
println!("{} Error: file not found", "✗".red().bold());
println!("{} Info: processing 10 files", "ℹ".blue().bold());
```

### Respecting NO_COLOR

```rust
use owo_colors::{OwoColorize, Stream};

fn print_status(message: &str, is_error: bool) {
    let stream = if is_error { Stream::Stderr } else { Stream::Stdout };

    if is_error {
        eprintln!("{}", message.if_supports_color(stream, |text| text.red()));
    } else {
        println!("{}", mes