Directory Structure Enforcement

Overview

This skill ensures all new code follows the documented directory structure standards. It validates file placement, enforces the Container/View pattern, and ensures proper organization of features, components, and tests.

When to Use

• Creating new components or screens
• Adding new features
• Creating hooks, utilities, or stores
• Adding test files
• Moving or restructuring existing code
• Reviewing file placement decisions

Root Directory Structure

Expo SDK 55+/56 adopts the /src convention: all application source lives under src/, while config, assets, tests, and tooling stay at the project root. Older projects keep source at the root. The structure below shows the /src layout; for a root-layout project, read src/<dir> as <dir>. The @/* TypeScript path alias points at ./src/* (or ./* for root layout), so imports are identical either way. The validator and lint/coverage configs auto-detect a src/ directory.

<project-root>/
├── src/                    # APPLICATION SOURCE (SDK 55+/56 /src convention)
│   ├── app/                # Expo Router - THIN WRAPPERS ONLY
│   ├── features/           # Feature modules - PRIMARY CODE LOCATION
│   ├── components/         # Shared components
│   │   ├── ui/             # GlueStack UI primitives
│   │   ├── icons/          # Icon components
│   │   ├── custom/         # Custom UI components
│   │   └── [ComponentName]/ # Feature-agnostic components
│   ├── hooks/              # Global hooks (with __tests__/)
│   ├── providers/          # Global React context providers (with __tests__/)
│   ├── stores/             # Global state - Apollo reactive variables (with __tests__/)
│   ├── utils/              # Utility functions (with __tests__/)
│   ├── lib/                # Utility libraries / integrations
│   ├── types/              # Global TypeScript types
│   ├── generated/          # Auto-generated GraphQL types (DO NOT EDIT)
│   ├── config/             # Configuration files
│   └── constants/          # Global constants
├── assets/                 # Static assets (fonts/, icons/, css/) — STAYS AT ROOT
├── e2e/                    # End-to-end tests (fixtures/, pages/, tests/, utils/) — STAYS AT ROOT
├── scripts/                # Build and development scripts — STAYS AT ROOT
├── public/                 # Public web assets — STAYS AT ROOT
├── __mocks__/              # Jest manual mocks — STAYS AT ROOT
├── docs/                   # Documentation — STAYS AT ROOT
└── projects/               # Project-specific files (archive/) — STAYS AT ROOT

Feature Module Structure

Each feature in features/ MUST follow this structure:

features/[feature-name]/
├── components/             # Feature-specific components
│   └── [ComponentName]/    # Each component in its own directory
│       ├── [ComponentName]Container.tsx
│       ├── [ComponentName]View.tsx
│       └── index.tsx
├── screens/                # Screen components (same pattern as components)
│   └── [ScreenName]/
│       ├── [ScreenName]Container.tsx
│       ├── [ScreenName]View.tsx
│       └── index.tsx
├── hooks/                  # Feature-specific hooks
│   └── __tests__/          # Hook tests
├── stores/                 # Feature state (Apollo reactive variables)
├── utils/                  # Feature utilities
│   └── __tests__/          # Utility tests
├── types.ts                # Feature TypeScript types
├── constants.ts            # Feature constants
├── config/                 # Feature configuration
└── operations.graphql      # GraphQL queries/mutations

Container/View Pattern Rules

Components and screens MUST follow the Container/View pattern:

Container ([Name]Container.tsx)

• Contains ALL business logic
• Uses hooks (useState, useEffect, useCallback, useMemo)
• Manages state and side effects
• Passes data and handlers as props to View
• ONLY renders the corresponding View component

View ([Name]View.tsx)

• Pure presentation component
• Receives ALL data via props
• MUST be wrapped in memo()
• NO business logic or hooks (except UI-specific like useRef for scroll)
• Handles conditional rendering (loading, error, empty, populated states)

Index (index.tsx)

• Exports the Container as default
• May export types if needed

Example Structure

// PlayerCard/PlayerCardContainer.tsx
export const PlayerCardContainer = () => {
  const { data, loading } = useQuery(GET_PLAYER);
  const handleClick = useCallback(() => {}, []);
  return <PlayerCardView data={data} loading={loading} onClick={handleClick} />;
};

// PlayerCard/PlayerCardView.tsx
export const PlayerCardView = memo(({ data, loading, onClick }: Props) => {
  if (loading) return <Skeleton />;
  return <Pressable onPress={onClick}>...</Pressable>;
});

// PlayerCard/index.tsx
export { PlayerCardContainer as default } from './PlayerCardContainer';

App Directory Rules

The app/ directory contains Expo Router file-based routing. Route files MUST be thin wrappers:

Correct Pattern

// app/(root)/(tabs)/players/[playerId]/index.tsx
import { Main } from "@/features/player-detail/screens/Main";

export default function PlayerDetailScreen() {
  return <Main />;
}

Violations

• Business logic in route files
• Component definitions in route files
• Hooks usage beyond route params
• Direct UI rendering beyond wrapper

Test File Placement

Test files MUST be placed in __tests__/ subdirectories:

hooks/
├── usePlayer.ts
└── __tests__/
    └── usePlayer.test.ts

utils/
├── formatDate.ts
└── __tests__/
    └── formatDate.test.ts

Test File Naming

• Unit tests: *.test.ts or *.test.tsx
• Spec tests: *.spec.ts or *.spec.tsx

Validation Script

To validate directory structure, run the validation script:

python3 .claude/skills/directory-structure/scripts/validate_structure.py [path]

The script checks:

1. Feature module structure completeness
2. Container/View pattern compliance
3. Test file placement in __tests__/ directories
4. Route file thin wrapper compliance
5. Proper naming conventions

Quick Reference

| File Type | Correct Location | | ------------------- | --------------------------------------- | | Feature component | features/[feature]/components/[Name]/ | | Feature screen | features/[feature]/screens/[Name]/ | | Feature hook | features/[feature]/hooks/ | | Feature test | features/[feature]/hooks/__tests__/ | | Global hook | hooks/ | | Global hook test | hooks/__tests__/ | | Shared component | components/[Name]/ | | UI primitive | components/ui/ | | Global utility | utils/ | | Global utility test | utils/__tests__/ | | Route wrapper | app/(root)/... | | GraphQL types | generated/ (auto-generated) |

Common Mistakes to Avoid

1. Placing feature code in app/ - Route files are wrappers only
2. Test files alongside source - Must be in __tests__/ subdirectory
3. Missing Container/View split - Every component needs both files
4. Business logic in View - Views are pure presentation only
5. Multiple components per file - One component per file, enforced by ESLint
6. Barrel exports - Never use index.ts to re-export multiple components