Zero to Hero in Jest Unit and Integration Testing with React

Create a fresh React app with npx create-react-app, open it in Visual Studio Code, and use the pre-installed testing libraries, including testing library and jest-dom, to run tests.

Open and simplify the test file, remove extra code, and create a minimal React app with an h2, an input placeholder enter email, and a basic ul for testing.

Write and run your first test for a React app by rendering the app component, locating a button with getByRole, and asserting its presence with jest-dom.

Learn to determine element roles in React tests by logging roles with testing library's logRoles, then fetch elements using getByTestId and test with role-based selectors.

Learn the differences between getBy, queryBy, and findBy in the testing library, including behavior with found, not found, and multiple matches, and how getAllBy and findAllBy relate to asynchronous testing.

Use getBy, getAllBy, and queryBy in Jest tests to handle button elements, resolve single or multiple matches, and assert presence or absence in the document.

Validate unit tests for a feedback form in React and integration testing for feedback overview; ensure the form includes a textbox, checkbox, and a button enabled only when input exists.

Demonstrates test driven development by writing tests first, then code to pass them, organizing a tests folder with a feedback form and feedback overview components, and installing a code-generation extension.

Learn to write an onload test case for a feedback form in a React app, rendering the component and asserting input, checkbox, and button existence and initial disabled state.

group related tests into a describe block to improve readability, then validate that a button enables only when the text input and checkbox are both filled, using placeholder text queries.

Simulate user interactions by entering text in a textbox and ticking a checkbox to enable the button, using fireEvent change and click events in Jest tests.

Explore the React project flow and structure, from public/index.html and the root div to index.js rendering the app and a feedback form component with component CSS; practice test‑driven development.

Create and use state variables with the useState hook to bind form inputs—text box and checkbox—to state. Set default values and handlers to store user feedback.

Learn that in React, a functional component is an arrow function that returns JSX, which must be wrapped by a parent element or fragment with opening and closing tags.

Develop a React feedback form by binding an input to a state variable with onChange and enabling the submit button only when the checkbox is checked.

Compare manual testing with unit tests in a test-driven workflow, using npm test to validate functionality and catch regressions before code changes.

Replace fireEvent with userEvent to test real user interactions in React tests, including typing and clicking. Learn proper imports, async handling, and common setup patterns.

Write unit tests for the feedback overview component in React, ensuring empty feedback shows no feedback found and a non-empty list renders as n rows via parent props.

Develop a Jest test for the feedback overview component to cover the no feedback found scenario, asserting that a no feedback message appears when the feedback list is empty.

demonstrates test driven development for Jest unit and integration testing with React by validating a feedback found scenario, using get by text, query by text, and list item count expectations.

Develop a feedback overview component in a React app, passing a feedback list via props, rendering items with map and keys, and handling empty states.

Diagnose and fix failing React Jest tests by debugging text matching, handling empty inputs, and ensuring the correct no feedback scenarios are rendered, demonstrating practical unit testing for React components.

Improve your test cases by replacing hard coded data with feedbacks.length, so tests automatically adapt as entries change, boosting code quality and maintainability.

Explore integration testing scenarios for a feedback app by verifying that adding new feedback to the list preserves existing items, and that the feedback form and overview components interact correctly.

Define an integration test that renders the app component, fills the text box with new feedback, checks the checkbox, clicks the submit button, and verifies the new feedback appears.

Implement integration test scenario two using Jest with React, reinforcing unit and integration testing skills for reliable component interactions.

Develop and test the functionality for adding new feedback in a React app, using Jest unit and integration tests.

Learn how to mock API calls for unit and integration tests in a React Jest workflow, bypassing real back-end calls to improve test speed and reliability.

Install the mock service worker (msw) to mock API calls and use findBy queries to wait for responses, then define GraphQL or API mocks in a handler file.

Create a mock msw handler for the create feedback endpoint, intercepting frontend calls to localhost:5000, returning a fake response with an id and the submitted text.

Set up and integrate a mock server by adding a handler in the mock folder, importing mock service worker settings, and starting the server, with tests updated to call it.

Update the integration test to switch from get to find by text, await promises, and intercept the save feedback api call, then add the endpoint to make the test pass.

Implement a fetch-based API call to save user feedback using async/await, configuring post requests with JSON headers and stringified body, and confirm integration tests pass.

Debug a passing Jest unit and integration test in React, fix input duplication by adding a clear after save, and validate the fix with screen.debug and integration tests.

Explore how integration tests run with a mock server to simulate api calls, intercept requests, and drive user interface updates with fake data.

Learn test driven development with a real backend API and a mock server, build a simple node express backend, and perform end-to-end manual testing from frontend to backend.