Gain insights into Jest, a versatile testing framework. Learn about fundamental and advanced testing techniques, from unit tests to CI/CD integration, for comprehensive JavaScript application testing.

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Run Tests

Run Tests - No Reset

Jest is a framework for testing applications developed in JavaScript. It has a well-documented and well-maintained range of tools to run tests in parallel. It is simple and works with projects using Babel, TypeScript, Node, React, Angular, Vue, etc. It works well for both client and server testing. 

This course covers Jest in-depth and is agnostic of any specific JavaScript framework. The course begins with the fundamentals of Jest testing, deconstructing the components of a test and covering how to compose basic unit tests and snapshot tests with Jest correctly. Next, it shows the testing of asynchronous code and the code that relies on external dependencies. Lastly, this course illustrates how Jest testing can effectively integrate into the real-world software development cycle through CI/CD pipeline.

It gives you hands-on experience in setting up Jest, types of testing, testing coverage, mocking, and native tooling depth.

…. To come 

… to come 

Mastering Jest: A Complete Guide to Testing

Test coverage is the metric by which we determine how many test files we are testing.

Test coverage is the metric by which we determine how much of our code is actually being tested.

Test coverage is the quantifiable metric by which we determine how good our tests are and how many bugs they catch.

Test coverage is the quantifiable metric by which we determine how many of the tests in our testing environment are passing.

**(Fill in the blank.)** The mechanism through which we leverage our test coverage to allow or block the merging of a GitHub pull request is called ________.

(Fill in the blank.) The mechanism through which we leverage our test coverage to allow or block the merging of a GitHub pull request is called ________.

Which is _not_ a specified metric provided by Jest's test coverage?

Which is not a specified metric provided by Jest’s test coverage?

What can we use test coverage as a gatekeeper to?


What can we use test coverage as a gatekeeper to?

Testing thresholds are a minimum percentage of tests that must pass.

Testing thresholds are a minimum number of files that must be tested.

Testing thresholds are a minimum percentage of our overall code that is executed in, or covered by, our tests.

Testing thresholds are a minimum number of types of tests that we have covered, including unit, integration, and snapshot testing.

Which statement best describes testing thresholds?

Which statement best describes testing thresholds?

**(True or False)** CI/CD pipelines can block an action only when thresholds are not met but not when a test fails.

(True or False) CI/CD pipelines can block an action only when thresholds are not met but not when a test fails.

**(Select all that apply.)** Which options are for setting testing threshold values?


(Select all that apply.) Which options are for setting testing threshold values?

Quiz yourself on test coverage and integrating coverage thresholds with CI/CD pipelines.

Introduction

Setting Up Jest

Jest Matchers

Writing Unit Tests

Writing Snapshot Tests

Asynchronous Code

Mocking

Mocking External Libraries

Working with Jest Mocks

Setup & Teardown

Test Coverage & CI/CD Pipelines

Test Coverage in Jest

Conclusion

Bonus: Best Practices

Bonus: Resources for Continued Learning

Appendix

Quiz on Test Coverage and CI/CD Pipelines