# Testing Instructions

## Framework and Tools

- **Vitest** is the recommended testing framework.  
  [Vitest Documentation (latest)](https://context7.com/vitest-dev/vitest/llms.txt?topic=getting+started)
- **Jest** and **Spectator** are **deprecated**.  
  Do not use them for new tests. Existing tests should be migrated to Vitest where possible.

## Guidelines

1. **Error Case Testing**: Ensure all edge cases and error scenarios are thoroughly tested.
2. **Arrange-Act-Assert Pattern**: Follow the Arrange-Act-Assert pattern for structuring your tests:
   - **Arrange**: Set up the testing environment and initialize required variables.
   - **Act**: Execute the functionality being tested.
   - **Assert**: Verify the expected outcomes.

## Best Practices

- Write clear and descriptive test names.
- Ensure tests are isolated and do not depend on each other.
- Mock external dependencies to avoid side effects.
- Aim for high code coverage without compromising test quality.

## Example Test Structure

```typescript
// Example using Vitest (Jest and Spectator are deprecated)
import { describe, it, expect, beforeEach } from 'vitest';
import { render } from '@testing-library/angular';
import { MyComponent } from './my-component.component';

describe('MyComponent', () => {
  let component: MyComponent;

  beforeEach(async () => {
    const { fixture } = await render(MyComponent);
    component = fixture.componentInstance;
  });

  it('should display the correct title', async () => {
    // Arrange
    const expectedTitle = 'Hello World';

    // Act
    component.title = expectedTitle;
    // If using Angular, trigger change detection:
    // fixture.detectChanges();

    // Assert
    const compiled = fixture.nativeElement as HTMLElement;
    expect(compiled.querySelector('h1')?.textContent).toBe(expectedTitle);
  });

  it('should handle error cases gracefully', () => {
    // Arrange
    const invalidInput = null;

    // Act
    component.input = invalidInput;

    // Assert
    expect(() => component.processInput()).toThrowError('Invalid input');
  });
});
```

## Additional Resources

- [Vitest Documentation (latest)](https://context7.com/vitest-dev/vitest/llms.txt?topic=getting+started)
- [Vitest Official Guide](https://vitest.dev/guide/)
- [Testing Library for Angular](https://testing-library.com/docs/angular-testing-library/intro/)
- **Jest** and **Spectator** documentation are deprecated