dart-best-practices

--- name: dart-best-practices description: |- General best practices for Dart development. Covers code style, effective Dart, and language features. license: Apache-2.0 key_features: - Code style guidelines - Effective Dart idioms - Language feature recommendations ---

# Dart Best Practices

## 1. When to use this skill Use this skill when: - Writing or reviewing Dart code. - Looking for guidance on idiomatic Dart usage.

## 2. Best Practices

### Multi-line Strings Prefer using multi-line strings (`'''`) over concatenating strings with `+` and `\n`, especially for large blocks of text like SQL queries, HTML, or PEM-encoded keys. This improves readability and avoids `lines_longer_than_80_chars` lint errors by allowing natural line breaks.

**Avoid:** ```dart final pem = '-----BEGIN RSA PRIVATE KEY-----\n' + base64Encode(fullBytes) + '\n-----END RSA PRIVATE KEY-----'; ```

**Prefer:** ```dart final pem = ''' -----BEGIN RSA PRIVATE KEY----- ${base64Encode(fullBytes)} -----END RSA PRIVATE KEY-----'''; ```

### Line Length Avoid lines longer than 80 characters, even in Markdown files and comments. This ensures code is readable in split-screen views and on smaller screens without horizontal scrolling.

**Prefer:** Target 80 characters for wrapping text. Exceptions are allowed for long URLs or identifiers that cannot be broken.

## Discovery

### Multi-line Strings To find candidates for multi-line strings, search for string concatenation with `+` involving newlines: - **Regex**: `['"]\s*\+\s*['"]` - **Regex**: `\+\s*['"].*\\n`

### Line Length - Rely on the `lines_longer_than_80_chars` lint from the analyzer.

## Related Skills

- **[dart-modern-features]**: For idiomatic usage of modern Dart features like Pattern Matching (useful for deep JSON extraction), Records, and Switch Expressions.

[dart-modern-features]: https://github.com/kevmoo/dash_skills/blob/main/skills/dart-modern-features/SKILL.md