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Marko Testing Library

Marko Testing Library builds on top of DOM Testing Library by adding APIs for working with Marko components.

npm install --save-dev @marko/testing-library

The problem​

You want to write maintainable tests for your Marko components. As a part of this goal, you want your tests to avoid including implementation details of your components and rather focus on making your tests give you the confidence for which they are intended. As part of this, you want your test suite to be maintainable in the long run so refactors of your components (changes to implementation but not functionality) don't break your tests and slow you and your team down.

This solution​

The @marko/testing-library is a very lightweight solution for testing Marko components. It provides light utility functions on top of @testing-library/dom in a way that encourages better testing practices. Its primary guiding principle is:

The more your tests resemble the way your software is used, the more confidence they can give you.

So rather than dealing with instances of rendered Marko components, your tests will work with actual DOM nodes. The utilities this library provides facilitate querying the DOM in the same way the user would. Finding for elements by their label text (just like a user would), finding links and buttons from their text (like a user would). It contains a small targeted API and can get out of your way if needed with some built-in escape hatches.

This library encourages your applications to be more accessible and allows you to get your tests closer to using your components the way a user will, which allows your tests to give you more confidence that your application will work when a real user uses it.

What this library is not:

  1. A test runner or framework
  2. Specific to a testing framework, you can use it with Jest, mocha, or other test runners.

NOTE: This library is built on top of DOM Testing Library which is where most of the logic behind the queries is.