safe-wallet/apps/mobile/docs/code-style.md

Code Style Guidelines

Cyclomatic-complexity guidelines (lookup tables, early returns, switch for type discrimination, function-length limits) live in ../../web/docs/code-style.md and apply equally here.

Code Structure

General Components

• Components that are used across multiple features should reside in the src/components/ folder.
• Each component should have its own folder, structured as follows:

  Alert/
  - Alert.tsx
  - Alert.test.tsx
  - Alert.stories.tsx
  - index.tsx
  

• The main component implementation should be in a named file (e.g., Alert.tsx), and index.tsx should only be used for exporting the component.
• Reason: Using index.tsx allows for cleaner imports, e.g.,

  import { Alert } from 'src/components/Alert';
  

  instead of:

  import { Alert } from 'src/components/Alert/Alert';
  

Exporting Components

• Always prefer named exports over default exports.
  • Named exports make it easier to refactor and identify exports in a codebase.

Features and Screens

• Feature-specific components and screens should be implemented inside the src/features/ folder.

Example: Feature File Structure

For a feature called Assets, the file structure might look like this:

// src/features/Assets
- Assets.container.tsx
- index.tsx

• index.tsx should only export the Assets component/container.

Subcomponents for Features

• If a feature depends on multiple subcomponents unique to that feature, place them in a components subfolder. For example:

// src/features/Assets/components/AssetHeader
- AssetHeader.tsx
- AssetHeader.container.tsx
- index.tsx

Presentation vs. Container Components

• Presentation Components:

  • Responsible only for rendering the UI.
  • Receive data and callbacks via props.
  • Avoid direct manipulation of business logic.
  • Simple business logic can be included but should generally be extracted into hooks.

• Container Components:

  • Handle business logic (e.g., state management, API calls, etc.).
  • Pass necessary data and callbacks to the corresponding Presentation component.