Include examples of tests

[iandunn]

I've found it time consuming to get Jest properly configured with Babel and JSX and all the things. I think it'd be useful to include working testings and all the required build tool configs, in order to make this easier and more convenient for people.

[keesiemeijer]

I'm new to JS testing and this would be extremely helpful. There is very little documentation about setting up the test environment for custom blocks. From the few plugins that have it set up it's not entirely clear how it was done (and if it was done correctly).

[iandunn]

wp-scripts probably makes this easier, but the docs only talk about how to install the script, and don't have any examples of actual tests.

[iandunn]

Related wp-cli/ideas#103

[swissspidy]

This is still relevant.

I am having trouble getting Jest to run with wp-scripts, see today's discussion on Slack: https://wordpress.slack.com/archives/C02QB2JS7/p1556031641343900.

[iandunn]

I started a repo in order to try and get a minimal example working.

https://github.com/iandunn/wp-scripts-test-example

I forked https://github.com/eventespresso/event-espresso-core (props @nerrad) and started removing everything that wasn't absolutely necessary for unit tests. it'd be nice to add e2e as well, but so far i've only had time for unit.

It's working, but still requires a lot of stuff that seems like wp-scripts should take care of automatically. I ran out of time to experiment more, though.

cc @gziolo in case you have any insight into what (if anything) wp-scripts can handle, and what still needs work upsteam.

[gziolo]

Now that I nearly finished adding support for lint-js (#83), I will try to integrate unit and e2e tests into this repository.

I hope I can identify all the issues we have at the moment when working outside of Gutenberg. I anticipate we might want to be more strict about pattern matching for both types of tests. This should make documenting easier and further usage less confusing.

[iandunn]

That would be extremely helpful, thank you!

[iandunn]

As another example for people, @ryelle got unit tests working for WordCamp.org in WordPress/wordcamp.org#211.

[gziolo]

I opened #84 to perform my own explorations and identified a few places where we can improve WordPress packages to make it more seamless.

[gziolo]

Tests are located in:
https://github.com/WordPress/gutenberg-examples/tree/trunk/test

It had some further iterations and it works well now.