errorboundary.test.tsx

import { Scope } from '@sentry/browser';
import { fireEvent, render, screen } from '@testing-library/react';
import * as React from 'react';
import { useState } from 'react';

import {
  ErrorBoundary,
  ErrorBoundaryProps,
  isAtLeastReact17,
  UNKNOWN_COMPONENT,
  withErrorBoundary,
} from '../src/errorboundary';

const mockCaptureException = jest.fn();
const mockShowReportDialog = jest.fn();
const EVENT_ID = 'test-id-123';

jest.mock('@sentry/browser', () => {
  const actual = jest.requireActual('@sentry/browser');
  return {
    ...actual,
    captureException: (...args: unknown[]) => {
      mockCaptureException(...args);
      return EVENT_ID;
    },
    showReportDialog: (options: any) => {
      mockShowReportDialog(options);
    },
  };
});

function Boo({ title }: { title: string }): JSX.Element {
  throw new Error(title);
}

function Bam(): JSX.Element {
  const [title] = useState('boom');
  return <Boo title={title} />;
}

const TestApp: React.FC<ErrorBoundaryProps> = ({ children, ...props }) => {
  const [isError, setError] = React.useState(false);
  return (
    <ErrorBoundary
      {...props}
      onReset={(...args) => {
        setError(false);
        if (props.onReset) {
          props.onReset(...args);
        }
      }}
    >
      {isError ? <Bam /> : children}
      <button
        data-testid="errorBtn"
        onClick={() => {
          setError(true);
        }}
      />
    </ErrorBoundary>
  );
};

describe('withErrorBoundary', () => {
  it('sets displayName properly', () => {
    const TestComponent = () => <h1>Hello World</h1>;

    const Component = withErrorBoundary(TestComponent, { fallback: <h1>fallback</h1> });
    expect(Component.displayName).toBe('errorBoundary(TestComponent)');
  });

  it('defaults to an unknown displayName', () => {
    const Component = withErrorBoundary(() => <h1>Hello World</h1>, { fallback: <h1>fallback</h1> });
    expect(Component.displayName).toBe(`errorBoundary(${UNKNOWN_COMPONENT})`);
  });
});

describe('ErrorBoundary', () => {
  jest.spyOn(console, 'error').mockImplementation();

  afterEach(() => {
    mockCaptureException.mockClear();
    mockShowReportDialog.mockClear();
  });

  it('renders null if not given a valid `fallback` prop', () => {
    const { container } = render(
      // @ts-ignore Passing wrong type on purpose
      <ErrorBoundary fallback="Not a ReactElement">
        <Bam />
      </ErrorBoundary>,
    );

    expect(container.innerHTML).toBe('');
  });

  it('renders null if not given a valid `fallback` prop function', () => {
    const { container } = render(
      // @ts-ignore Passing wrong type on purpose
      <ErrorBoundary fallback={() => 'Not a ReactElement'}>
        <Bam />
      </ErrorBoundary>,
    );

    expect(container.innerHTML).toBe('');
  });

  it('renders a fallback on error', () => {
    const { container } = render(
      <ErrorBoundary fallback={<h1>Error Component</h1>}>
        <Bam />
      </ErrorBoundary>,
    );
    expect(container.innerHTML).toBe('<h1>Error Component</h1>');
  });

  it('calls `onMount` when mounted', () => {
    const mockOnMount = jest.fn();
    render(
      <ErrorBoundary fallback={<h1>Error Component</h1>} onMount={mockOnMount}>
        <h1>children</h1>
      </ErrorBoundary>,
    );

    expect(mockOnMount).toHaveBeenCalledTimes(1);
  });

  it('calls `onUnmount` when unmounted', () => {
    const mockOnUnmount = jest.fn();
    const { unmount } = render(
      <ErrorBoundary fallback={<h1>Error Component</h1>} onUnmount={mockOnUnmount}>
        <h1>children</h1>
      </ErrorBoundary>,
    );

    expect(mockOnUnmount).toHaveBeenCalledTimes(0);
    unmount();
    expect(mockOnUnmount).toHaveBeenCalledTimes(1);
    expect(mockOnUnmount).toHaveBeenCalledWith(null, null, null);
  });

  it('renders children correctly when there is no error', () => {
    const { container } = render(
      <ErrorBoundary fallback={<h1>Error Component</h1>}>
        <h1>children</h1>
      </ErrorBoundary>,
    );

    expect(container.innerHTML).toBe('<h1>children</h1>');
  });

  it('supports rendering children as a function', () => {
    const { container } = render(
      <ErrorBoundary fallback={<h1>Error Component</h1>}>{() => <h1>children</h1>}</ErrorBoundary>,
    );

    expect(container.innerHTML).toBe('<h1>children</h1>');
  });

  describe('fallback', () => {
    it('renders a fallback component', async () => {
      const { container } = render(
        <TestApp fallback={<p>You have hit an error</p>}>
          <h1>children</h1>
        </TestApp>,
      );

      expect(container.innerHTML).toContain('<h1>children</h1>');

      const btn = screen.getByTestId('errorBtn');
      fireEvent.click(btn);

      expect(container.innerHTML).not.toContain('<h1>children</h1>');
      expect(container.innerHTML).toBe('<p>You have hit an error</p>');
    });

    it('renders a render props component', async () => {
      let errorString = '';
      let compStack = '';
      let eventIdString = '';
      const { container } = render(
        <TestApp
          fallback={({ error, componentStack, eventId }) => {
            if (error && componentStack && eventId) {
              errorString = error.toString();
              compStack = componentStack;
              eventIdString = eventId;
            }
            return <div>Fallback here</div>;
          }}
        >
          <h1>children</h1>
        </TestApp>,
      );

      expect(container.innerHTML).toContain('<h1>children</h1>');

      const btn = screen.getByTestId('errorBtn');
      fireEvent.click(btn);

      expect(container.innerHTML).not.toContain('<h1>children</h1');
      expect(container.innerHTML).toBe('<div>Fallback here</div>');

      expect(errorString).toBe('Error: boom');
      /*
        at Boo (/path/to/sentry-javascript/packages/react/test/errorboundary.test.tsx:23:20)
        at Bam (/path/to/sentry-javascript/packages/react/test/errorboundary.test.tsx:40:11)
        at ErrorBoundary (/path/to/sentry-javascript/packages/react/src/errorboundary.tsx:2026:39)
        at TestApp (/path/to/sentry-javascript/packages/react/test/errorboundary.test.tsx:22:23)
      */
      expect(compStack).toMatch(
        /\s+(at Boo) \(.*?\)\s+(at Bam) \(.*?\)\s+(at ErrorBoundary) \(.*?\)\s+(at TestApp) \(.*?\)/g,
      );
      expect(eventIdString).toBe(EVENT_ID);
    });
  });

  describe('error', () => {
    it('calls `componentDidCatch() when an error occurs`', () => {
      const mockOnError = jest.fn();
      render(
        <TestApp fallback={<p>You have hit an error</p>} onError={mockOnError}>
          <h1>children</h1>
        </TestApp>,
      );

      expect(mockOnError).toHaveBeenCalledTimes(0);
      expect(mockCaptureException).toHaveBeenCalledTimes(0);

      const btn = screen.getByTestId('errorBtn');
      fireEvent.click(btn);

      expect(mockOnError).toHaveBeenCalledTimes(1);
      expect(mockOnError).toHaveBeenCalledWith(expect.any(Error), expect.any(String), expect.any(String));

      expect(mockCaptureException).toHaveBeenCalledTimes(1);
      expect(mockCaptureException).toHaveBeenLastCalledWith(expect.any(Error), {
        contexts: { react: { componentStack: expect.any(String) } },
      });

      expect(mockOnError.mock.calls[0][0]).toEqual(mockCaptureException.mock.calls[0][0]);

      // Check if error.cause -> react component stack
      const error = mockCaptureException.mock.calls[0][0];
      const cause = error.cause;
      expect(cause.stack).toEqual(mockCaptureException.mock.calls[0][1].contexts.react.componentStack);
      expect(cause.name).toContain('React ErrorBoundary');
      expect(cause.message).toEqual(error.message);
    });

    it('calls `beforeCapture()` when an error occurs', () => {
      const mockBeforeCapture = jest.fn();

      const testBeforeCapture = (...args: any[]) => {
        expect(mockCaptureException).toHaveBeenCalledTimes(0);
        mockBeforeCapture(...args);
      };

      render(
        <TestApp fallback={<p>You have hit an error</p>} beforeCapture={testBeforeCapture}>
          <h1>children</h1>
        </TestApp>,
      );

      expect(mockBeforeCapture).toHaveBeenCalledTimes(0);
      expect(mockCaptureException).toHaveBeenCalledTimes(0);

      const btn = screen.getByTestId('errorBtn');
      fireEvent.click(btn);

      expect(mockBeforeCapture).toHaveBeenCalledTimes(1);
      expect(mockBeforeCapture).toHaveBeenLastCalledWith(expect.any(Scope), expect.any(Error), expect.any(String));
      expect(mockCaptureException).toHaveBeenCalledTimes(1);
    });

    it('shows a Sentry Report Dialog with correct options', () => {
      const options = { title: 'custom title' };
      render(
        <TestApp fallback={<p>You have hit an error</p>} showDialog dialogOptions={options}>
          <h1>children</h1>
        </TestApp>,
      );

      expect(mockShowReportDialog).toHaveBeenCalledTimes(0);

      const btn = screen.getByTestId('errorBtn');
      fireEvent.click(btn);

      expect(mockShowReportDialog).toHaveBeenCalledTimes(1);
      expect(mockShowReportDialog).toHaveBeenCalledWith({ ...options, eventId: EVENT_ID });
    });

    it('resets to initial state when reset', async () => {
      const { container } = render(
        <TestApp fallback={({ resetError }) => <button data-testid="reset" onClick={resetError} />}>
          <h1>children</h1>
        </TestApp>,
      );

      expect(container.innerHTML).toContain('<h1>children</h1>');
      const btn = screen.getByTestId('errorBtn');
      fireEvent.click(btn);
      expect(container.innerHTML).toContain('<button data-testid="reset">');

      const reset = screen.getByTestId('reset');
      fireEvent.click(reset);

      expect(container.innerHTML).toContain('<h1>children</h1>');
    });

    it('calls `onReset()` when reset', () => {
      const mockOnReset = jest.fn();
      render(
        <TestApp
          onReset={mockOnReset}
          fallback={({ resetError }) => <button data-testid="reset" onClick={resetError} />}
        >
          <h1>children</h1>
        </TestApp>,
      );

      expect(mockOnReset).toHaveBeenCalledTimes(0);
      const btn = screen.getByTestId('errorBtn');
      fireEvent.click(btn);
      expect(mockOnReset).toHaveBeenCalledTimes(0);

      const reset = screen.getByTestId('reset');
      fireEvent.click(reset);

      expect(mockOnReset).toHaveBeenCalledTimes(1);
      expect(mockOnReset).toHaveBeenCalledWith(expect.any(Error), expect.any(String), expect.any(String));
    });
  });
});

describe('isAtLeastReact17', () => {
  test.each([
    ['React 15 with no patch', '15.0', false],
    ['React 15 with no patch and no minor', '15.5', false],
    ['React 16', '16.0.4', false],
    ['React 17', '17.0.0', true],
    ['React 17 with no patch', '17.4', true],
    ['React 17 with no patch and no minor', '17', true],
    ['React 18', '18.1.0', true],
    ['React 19', '19.0.0', true],
  ])('%s', (_: string, input: string, output: ReturnType<typeof isAtLeastReact17>) => {
    expect(isAtLeastReact17(input)).toBe(output);
  });
});