FEATURE: Introduce theme/component QUnit tests (take 2) (PR #12661)

This PR allows themes and theme components to have QUnit tests. To add tests to your theme/component, create a top-level directory in your theme and name it test, and Discourse will save all the files in that directory (and its sub-directories) as “tests files” in the database. While tests files/directories are not required to be organized in a specific way, we recommend that you follow Discourse core’s tests structure.

Writing theme tests should be identical to writing plugins or core tests; all the import statements and APIs that you see in core (or plugins) to define/setup tests should just work in themes.

You do need a working Discourse install to run theme tests, and you have 2 ways to run theme tests:

  • In the browser at the /qunit route. /qunit will run tests of all active themes/components as well as core and plugins. The /qunit now accepts a theme_name or theme_url params that you can use to run tests of a specific theme/component like so: /qunit?theme_name=<your_theme_name>.

  • In the command line using the themes:qunit rake task. This take is meant to run tests of a single theme/component so you need to provide it with a theme name or URL like so: bundle exec rake themes:qunit[name=<theme_name>] or bundle exec rake themes:qunit[url=<theme_url>].

There are some refactors to how Discourse processes JavaScript that comes with themes/components, and these refactors may break your JS customizations:

This PR also improves theme error handling in Discourse. We will now be able to catch errors that occur when theme initializers are run and prevent them from breaking the site and other themes/components.


@eviltrout this PR is mostly the same as the original PR; the only difference is this new commit FEATURE: Introduce theme/component QUnit tests (take 2) by OsamaSayegh · Pull Request #12661 · discourse/discourse · GitHub which improves theme error handling. Do you have any thoughts/questions/objections to the changes I made there?

No, I do not have any questions or changes. Looks great!

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