Documentation

Class: Login

Description: This class represents the Login component, which handles user authentication and redirects based on authentication status. It renders different UI elements based on whether the user is logged in or not.

Methods

Method: useHistory

Description: This method is a mock implementation of useHistory hook, which provides functions for navigation. It is used in testing to simulate browser history behavior without actually interacting with the browser.

Parameters:

  • None

Returns:

  • Object: Returns an object containing the replace method, which is a mock implementation of the replace function used for changing the current URL without adding a new entry to the history stack.

Throws:

  • None

Example:

// Example usage in a test
import { useHistory } from "react-router-dom";

const history = useHistory();

// Replace the current URL with a new one
history.replace('/new-url');

Test Suite: Login.test.js

Description: This test suite contains unit tests for the Login component, covering various scenarios related to user authentication, installation status, and error handling. The tests use the react-test-renderer library to create shallow renderings of the component, and mock functions are employed to isolate and control the behavior of dependent modules.

Test Cases

Test Case: User is logged out

Description: This test case verifies the behavior of the Login component when the user is not logged in. It checks that the UI displays login options for GitHub, GitLab, and Bitbucket.

Code:

describe("User is logged out", () => {
  it("shows login options when not authenticated", async () => {
    checkAuthRequest.mockReturnValueOnce([false]);
    const tree = renderer.create(<Login />);
    await renderer.act(() => Promise.resolve());
    expect(tree).toMatchSnapshot();
    tree.root.findByProps({
      text: "Log In with GitHub",
    });
    tree.root.findByProps({
      text: "Log In with GitLab",
    });
    tree.root.findByProps({
      text: "Log In with Bitbucket",
    });
  });
});

Test Case: Logging in

Description: This test case verifies the redirect behavior when the user clicks on the "Log In with GitHub" button. It ensures that the redirect function is called with the correct redirect URL.

Code:

describe("Logging in", () => {
  it("should redirect the user after clicking", async () => {
    const GITHUB_REDIRECT = `${GITHUB_AUTH_URL}&redirect_uri=${window.location.origin}`;
    checkAuthRequest.mockReturnValueOnce([false]);
    const tree = renderer.create(<Login />);
    await renderer.act(() => Promise.resolve());
    const button = tree.root.findByProps({
      text: "Log In with GitHub",
    });
    button.props.onClick();
    expect(redirect).toHaveBeenCalledWith(GITHUB_REDIRECT);
  });
});

Test Case: User is logged in

Description: This test case covers various scenarios when the user is logged in. It tests the following:

  • Invalid Auth Code: It checks that an error message is displayed if the authentication code is invalid.
  • Not Installed: It verifies that the user is redirected to the installation URL if the app is not installed.
  • Authenticated and Installed: It ensures that the user is redirected to the dashboard if they are both authenticated and have the app installed.

Code:

describe("User is logged in", () => {
  it("should show the error message if the auth code is invalid", async () => {
    checkAuthRequest.mockReturnValueOnce([true, "code"]);
    authenticate.mockReturnValueOnce(Promise.resolve(false));
    const tree = renderer.create(<Login />);
    await renderer.act(() => Promise.resolve());
    const textContent = tree.root.findByProps({
      className: "error",
    }).children[0];
    expect(textContent).toEqual(
      "Error authenticating. Try again or contact support.",
    );
    expect();

    expect(tree).toMatchSnapshot();
  });

  it("should tell the user they have not installed the app", async () => {
    checkAuthRequest.mockReturnValueOnce([true, "code"]);
    authenticate.mockReturnValueOnce(Promise.resolve(true));
    isInstalled.mockReturnValueOnce(false);
    const tree = renderer.create(<Login />);
    await renderer.act(() => Promise.resolve());
    expect(redirect).toHaveBeenCalledWith(GITHUB_INSTALL_URL);
    expect(tree).toMatchSnapshot();
  });

  it("Should redirect to the dashboard if authenticated and installed", async () => {
    checkAuthRequest.mockReturnValueOnce([true, "code"]);
    authenticate.mockReturnValueOnce(Promise.resolve(true));
    isInstalled.mockReturnValueOnce(true);
    const tree = renderer.create(<Login />);
    await renderer.act(() => Promise.resolve());
    expect(redirect).toHaveBeenCalledWith();
    expect(tree).toMatchSnapshot();
  });
});

Important Considerations:

  • Mocking: The test suite extensively uses mocking to isolate the behavior of dependent modules. This helps ensure that tests are focused on the specific functionality of the Login component and not affected by external factors.
  • Snapshot Testing: The tests use snapshot testing to verify the rendered output of the component. This approach helps detect unintended changes to the UI structure.
  • Testing Environment: These tests are designed to be run in a controlled environment, such as a test runner or a development environment. They may require specific configurations or dependencies to execute correctly.
  • Real World Interaction: While the tests cover various scenarios, it's important to remember that they simulate interactions rather than directly interacting with a real browser. Real-world testing, such as end-to-end testing, can provide additional assurance of the component's functionality in a live environment.