---

name: testing-standards description: Ensures all new screens/components have unit tests with proper coverage. Validates test files exist for loading, error, success, and state-transition states. Checks that backend handlers have corresponding test files. Use when creating or modifying frontend screens, components, or backend handlers.

Testing Standards

This skill enforces Ishkul's mandatory unit testing requirements to prevent production issues like the React error #310 caused by missing state transition tests.

Frontend Testing Requirements

Screens

Every new screen MUST have a test file at:

Copyfrontend/src/screens/__tests__/ScreenName.test.tsx

Required test coverage:

• Loading state - Initial loading UI
• Error state - Error handling and display
• Empty state - No data scenarios
• Success state - Data loaded correctly
• State transitions - Critical for catching React Rules of Hooks violations

Test File Template for Screens

Copydescribe('ScreenName', () => {
  describe('Loading State', () => {
    it('should display loading indicator', () => { /* test */ });
  });

  describe('Error State', () => {
    it('should display error message', () => { /* test */ });
    it('should allow retry', () => { /* test */ });
  });

  describe('Success State', () => {
    it('should display data correctly', () => { /* test */ });
  });

  describe('State Transitions (Rules of Hooks)', () => {
    it('should handle transition from loading to success', () => { /* test */ });
    it('should handle transition from loading to error', () => { /* test */ });
    it('should handle transition from error to loading (retry)', () => { /* test */ });
  });
});

Components

Every new component MUST have a test file at:

Copyfrontend/src/components/__tests__/ComponentName.test.tsx

Required coverage:

• All props combinations
• User interactions (clicks, input changes)
• Edge cases (empty props, long text, etc.)

Backend Testing Requirements

Every new handler MUST have a test file at:

Copybackend/internal/handlers/handler_name_test.go

Required coverage:

• Success cases
• Error cases (invalid input, auth failures)
• Edge cases

Running Tests

Frontend

Copy# Run specific test file
npm test -- --testPathPattern="YourNewFile.test"

# Run all tests
npm test

Backend

Copygo test ./...

Why This Matters

Missing state transition tests caused a production crash (React error #310) in LessonScreen where hooks were called after conditional returns. Always include state transition tests to catch these issues before deployment.