How to create and run automated tests for WordPress blocks

[bph]

Discussed in #24

^{Originally posted by juanmaguitar November 28, 2022}
An article about how to create and run automated tests for our custom blocks in WordPress could be useful for both the product itself and the extenders using blocks.

In fact, I see this content as a series of two posts:

• Unit Tests for Blocks: The first one covers a more granular way of testing blocks: Unit Tests with Jest to test a block from its main components (Edit and save)
• E2E Tests (or Integration Tests) for Blocks: A second one covering a more generic way of testing blocks: End-to-end tests with playwright to test the expected block behavior in the WordPress context (the block is properly registered, the frontend behavior works as expected, ...)

The first post could be called "Unit Testing for Blocks" and could cover the following ideas:

• Why having automated tests is a good way to ensure our block work as expected and to document it (among other benefits)
• The difference between Unit Tests and E2E tests
• What is Jest
• Preparing the environment in our project to test our block with Jest
• What to test in a Unit Test for a block - creating some tests for our block
• Launching our test in local
• Bonus: Creating a CI/CD pipeline with GitHub Actions to only allow merge if tests are passing

These posts could even include a brief explanation of what BDD is, what CI is, and how these tests allow the Gutenberg project to grow in a more solid way.

Inspired by this answer in the support forums

[flexseth]

+1 great content idea