Add tests for useFormError hook and FormField component

- Introduced `useFormError.test.tsx` to validate error handling, server error integration, and form behavior.
- Added `FormField.test.tsx`, covering rendering, accessibility, error handling, and prop forwarding.
- Updated Jest coverage exclusions to include `middleware.ts` (no logic to test).
This commit is contained in:
2025-11-02 17:14:12 +01:00
parent 0e554ef35e
commit ac3fac0426
3 changed files with 567 additions and 0 deletions

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@@ -28,6 +28,7 @@ const customJestConfig = {
'!src/app/**', // Next.js app directory - layout/page files (test in E2E)
'!src/**/index.{js,jsx,ts,tsx}', // Re-export index files - no logic to test
'!src/lib/utils/cn.ts', // Simple utility function from shadcn
'!src/middleware.ts', // middleware.ts - no logic to test
],
coverageThreshold: {
global: {

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@@ -0,0 +1,303 @@
/**
* Tests for FormField Component
* Verifies form field rendering, accessibility, and error handling
*/
import { render, screen } from '@testing-library/react';
import { FormField } from '@/components/forms/FormField';
import { FieldError } from 'react-hook-form';
describe('FormField', () => {
describe('Basic Rendering', () => {
it('renders with label and input', () => {
render(
<FormField
label="Email"
name="email"
type="email"
/>
);
expect(screen.getByLabelText('Email')).toBeInTheDocument();
expect(screen.getByRole('textbox')).toBeInTheDocument();
});
it('renders with description', () => {
render(
<FormField
label="Username"
name="username"
description="Choose a unique username"
/>
);
expect(screen.getByText('Choose a unique username')).toBeInTheDocument();
});
it('renders children content', () => {
render(
<FormField
label="Password"
name="password"
type="password"
>
<p>Password requirements: 8+ characters</p>
</FormField>
);
expect(screen.getByText(/Password requirements/)).toBeInTheDocument();
});
});
describe('Required Field', () => {
it('shows asterisk when required is true', () => {
render(
<FormField
label="Email"
name="email"
required
/>
);
expect(screen.getByText('*')).toBeInTheDocument();
});
it('does not show asterisk when required is false', () => {
render(
<FormField
label="Email"
name="email"
required={false}
/>
);
expect(screen.queryByText('*')).not.toBeInTheDocument();
});
});
describe('Error Handling', () => {
it('displays error message when error prop is provided', () => {
const error: FieldError = {
type: 'required',
message: 'Email is required',
};
render(
<FormField
label="Email"
name="email"
error={error}
/>
);
expect(screen.getByText('Email is required')).toBeInTheDocument();
});
it('sets aria-invalid when error exists', () => {
const error: FieldError = {
type: 'required',
message: 'Email is required',
};
render(
<FormField
label="Email"
name="email"
error={error}
/>
);
const input = screen.getByRole('textbox');
expect(input).toHaveAttribute('aria-invalid', 'true');
});
it('sets aria-describedby with error ID when error exists', () => {
const error: FieldError = {
type: 'required',
message: 'Email is required',
};
render(
<FormField
label="Email"
name="email"
error={error}
/>
);
const input = screen.getByRole('textbox');
expect(input).toHaveAttribute('aria-describedby', 'email-error');
});
it('renders error with role="alert"', () => {
const error: FieldError = {
type: 'required',
message: 'Email is required',
};
render(
<FormField
label="Email"
name="email"
error={error}
/>
);
const errorElement = screen.getByRole('alert');
expect(errorElement).toHaveTextContent('Email is required');
});
});
describe('Accessibility', () => {
it('links label to input via htmlFor/id', () => {
render(
<FormField
label="Email"
name="email"
/>
);
const label = screen.getByText('Email');
const input = screen.getByRole('textbox');
expect(label).toHaveAttribute('for', 'email');
expect(input).toHaveAttribute('id', 'email');
});
it('sets aria-describedby with description ID when description exists', () => {
render(
<FormField
label="Username"
name="username"
description="Choose a unique username"
/>
);
const input = screen.getByRole('textbox');
expect(input).toHaveAttribute('aria-describedby', 'username-description');
});
it('combines error and description IDs in aria-describedby', () => {
const error: FieldError = {
type: 'required',
message: 'Username is required',
};
render(
<FormField
label="Username"
name="username"
description="Choose a unique username"
error={error}
/>
);
const input = screen.getByRole('textbox');
expect(input).toHaveAttribute('aria-describedby', 'username-error username-description');
});
});
describe('Input Props Forwarding', () => {
it('forwards input props correctly', () => {
render(
<FormField
label="Email"
name="email"
type="email"
placeholder="Enter your email"
disabled
/>
);
const input = screen.getByRole('textbox');
expect(input).toHaveAttribute('type', 'email');
expect(input).toHaveAttribute('placeholder', 'Enter your email');
expect(input).toBeDisabled();
});
it('accepts register() props', () => {
const registerProps = {
name: 'email',
onChange: jest.fn(),
onBlur: jest.fn(),
ref: jest.fn(),
};
render(
<FormField
label="Email"
{...registerProps}
/>
);
const input = screen.getByRole('textbox');
expect(input).toBeInTheDocument();
// Input ID should match the name from register props
expect(input).toHaveAttribute('id', 'email');
});
});
describe('Error Cases', () => {
it('throws error when name is not provided', () => {
// Suppress console.error for this test
const consoleError = jest.spyOn(console, 'error').mockImplementation(() => {});
expect(() => {
render(
<FormField
label="Email"
// @ts-expect-error - Testing missing name
name={undefined}
/>
);
}).toThrow('FormField: name must be provided either explicitly or via register()');
consoleError.mockRestore();
});
});
describe('Layout and Styling', () => {
it('applies correct spacing classes', () => {
const { container } = render(
<FormField
label="Email"
name="email"
/>
);
const wrapper = container.firstChild as HTMLElement;
expect(wrapper).toHaveClass('space-y-2');
});
it('applies correct error styling', () => {
const error: FieldError = {
type: 'required',
message: 'Email is required',
};
render(
<FormField
label="Email"
name="email"
error={error}
/>
);
const errorElement = screen.getByRole('alert');
expect(errorElement).toHaveClass('text-sm', 'text-destructive');
});
it('applies correct description styling', () => {
const { container } = render(
<FormField
label="Email"
name="email"
description="We'll never share your email"
/>
);
const description = container.querySelector('#email-description');
expect(description).toHaveClass('text-sm', 'text-muted-foreground');
});
});
});

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@@ -0,0 +1,263 @@
/**
* Tests for useFormError Hook
* Verifies form error handling and API error integration
*/
import { renderHook, act } from '@testing-library/react';
import { useForm } from 'react-hook-form';
import { useFormError } from '@/components/forms/useFormError';
interface TestFormData {
email: string;
password: string;
username: string;
}
// Helper to render both hooks together in one scope
function useTestForm(defaultValues?: Partial<TestFormData>) {
const form = useForm<TestFormData>({
defaultValues: defaultValues || {},
});
const formError = useFormError(form);
return { form, formError };
}
describe('useFormError', () => {
describe('Initial State', () => {
it('initializes with null serverError', () => {
const { result } = renderHook(() => useTestForm());
expect(result.current.formError.serverError).toBeNull();
});
it('provides all expected functions', () => {
const { result } = renderHook(() => useTestForm());
expect(typeof result.current.formError.setServerError).toBe('function');
expect(typeof result.current.formError.handleFormError).toBe('function');
expect(typeof result.current.formError.clearErrors).toBe('function');
});
});
describe('setServerError', () => {
it('sets server error message', () => {
const { result } = renderHook(() => useTestForm());
act(() => {
result.current.formError.setServerError('Custom error message');
});
expect(result.current.formError.serverError).toBe('Custom error message');
});
it('clears server error when set to null', () => {
const { result } = renderHook(() => useTestForm());
act(() => {
result.current.formError.setServerError('Error message');
});
act(() => {
result.current.formError.setServerError(null);
});
expect(result.current.formError.serverError).toBeNull();
});
});
describe('handleFormError - API Error Array', () => {
it('handles API error with general error message', () => {
const { result } = renderHook(() => useTestForm());
const apiError = [
{ code: 'AUTH_001', message: 'Invalid credentials' },
];
act(() => {
result.current.formError.handleFormError(apiError);
});
expect(result.current.formError.serverError).toBe('Invalid credentials');
});
it('handles multiple general errors (takes first non-field error)', () => {
const { result } = renderHook(() => useTestForm());
const apiError = [
{ code: 'AUTH_001', message: 'Authentication failed' },
{ code: 'AUTH_002', message: 'Account is inactive' },
];
act(() => {
result.current.formError.handleFormError(apiError);
});
// Should take the first general error
expect(result.current.formError.serverError).toBe('Authentication failed');
});
it('handles API errors with field-specific errors without crashing', () => {
const { result } = renderHook(() =>
useTestForm({ email: '', password: '', username: '' })
);
const apiError = [
{ code: 'VAL_004', message: 'Email is required', field: 'email' },
{ code: 'VAL_003', message: 'Password too short', field: 'password' },
];
// Should not throw even though fields aren't registered
expect(() => {
act(() => {
result.current.formError.handleFormError(apiError);
});
}).not.toThrow();
// No general error should be set (all are field errors)
expect(result.current.formError.serverError).toBeNull();
});
});
describe('handleFormError - Non-API Errors', () => {
it('handles unexpected error format', () => {
const { result } = renderHook(() => useTestForm());
const unexpectedError = new Error('Network error');
act(() => {
result.current.formError.handleFormError(unexpectedError);
});
expect(result.current.formError.serverError).toBe('An unexpected error occurred. Please try again.');
});
it('handles string errors', () => {
const { result } = renderHook(() => useTestForm());
act(() => {
result.current.formError.handleFormError('Some error string');
});
expect(result.current.formError.serverError).toBe('An unexpected error occurred. Please try again.');
});
it('handles null errors', () => {
const { result } = renderHook(() => useTestForm());
act(() => {
result.current.formError.handleFormError(null);
});
expect(result.current.formError.serverError).toBe('An unexpected error occurred. Please try again.');
});
it('handles undefined errors', () => {
const { result } = renderHook(() => useTestForm());
act(() => {
result.current.formError.handleFormError(undefined);
});
expect(result.current.formError.serverError).toBe('An unexpected error occurred. Please try again.');
});
});
describe('clearErrors', () => {
it('clears server error', () => {
const { result } = renderHook(() => useTestForm());
act(() => {
result.current.formError.setServerError('Some error');
});
act(() => {
result.current.formError.clearErrors();
});
expect(result.current.formError.serverError).toBeNull();
});
it('clears form errors', () => {
const { result } = renderHook(() =>
useTestForm({ email: '', password: '', username: '' })
);
// Set field errors
act(() => {
result.current.form.setError('email', { message: 'Email error' });
result.current.form.setError('password', { message: 'Password error' });
});
// Clear all errors
act(() => {
result.current.formError.clearErrors();
});
expect(result.current.form.formState.errors.email).toBeUndefined();
expect(result.current.form.formState.errors.password).toBeUndefined();
});
it('clears both server and form errors', () => {
const { result } = renderHook(() =>
useTestForm({ email: '', password: '', username: '' })
);
act(() => {
result.current.formError.setServerError('Server error');
result.current.form.setError('email', { message: 'Email error' });
});
act(() => {
result.current.formError.clearErrors();
});
expect(result.current.formError.serverError).toBeNull();
expect(result.current.form.formState.errors.email).toBeUndefined();
});
});
describe('Integration Scenarios', () => {
it('handles typical login flow with API error', () => {
const { result } = renderHook(() =>
useTestForm({ email: '', password: '', username: '' })
);
// Simulate API error response
const apiError = [
{ code: 'AUTH_001', message: 'Invalid email or password' },
];
act(() => {
result.current.formError.handleFormError(apiError);
});
expect(result.current.formError.serverError).toBe('Invalid email or password');
});
it('clears error state on retry', () => {
const { result } = renderHook(() => useTestForm());
// First attempt - error
act(() => {
result.current.formError.setServerError('First error');
});
expect(result.current.formError.serverError).toBe('First error');
// Clear before retry
act(() => {
result.current.formError.clearErrors();
});
expect(result.current.formError.serverError).toBeNull();
// Second attempt - different error
act(() => {
result.current.formError.setServerError('Second error');
});
expect(result.current.formError.serverError).toBe('Second error');
});
});
});