Angular style guide

Angular Style Guide

Priority: P0 (CRITICAL)

Principles

• Single Responsibility: One component/service per file. Small functions (< 75 lines).
• Size Limits: Keep files under 400 lines. Refactor if larger.
• Strict Naming: kebab-case with type suffix (e.g., hero-list.component.ts, auth.service.ts, user.pipe.ts, app.routes.ts).
• Barrels: Use index.ts only for public APIs of specific features/libraries. Avoid deep barrel imports within the same feature — import directly. Incorrect barrel placement prevents tree-shaking.
• LIFT: Locate code quickly, Identify files by name, keep the Flattest structure possible, Try to be DRY.

Naming Standards

• Files: kebab-case.type.ts
• Classes: PascalCase + type suffix (HeroListComponent, AuthService)
• Directives: camelCase selector with app prefix (e.g., appHighlight)
• Pipes: camelCase name (e.g., truncate)
• Services: PascalCase + Service suffix (HeroService)
• Interfaces: No — do not use IUser or IHero. Name interfaces as nouns (e.g., User, Hero). This is not recommended by Angular style guide.

Folder Structure

• Core: src/app/core/ (singletons and global state).
• Shared: src/app/shared/ (reusable UI and pipes).
• Features: src/app/features/ (lazy-loaded features). Keep folder depth ≤3 levels.

Anti-Patterns

• No logic in templates: Move to the component class or a computed() signal.
• No deep nesting: Keep folder depth ≤3 levels.
• No I-prefix on interfaces: Name interfaces User, not IUser.

References

• Naming Conventions