Feature/testing

[trm217]

Changes requested in Issue 12

This PR includes the following changes:

1. Setup for testing using Jest and @testing-library/react
2. Test-suites for the following features:
   • different defaultThemes (4 test-cases)
   • using a custom storage-key (2 test-cases)
   • custom attribute (3 test-cases)
   • custom value-mapping (1 test-case)

[pacocoursey]

Amazing! This looks great, I'd be happy to merge already just to have some tests going on future PRs. A few more things we could add tests for:

• Forced theme
• Resolved theme (which also handles color-scheme)
• Ensuring theme is synced across all instances of useTheme hook

[trm217]

Regarding the test you mentioned, I suppose it would be cool to check those with Integration Tests. Especially for the media-query based one. Cypress might work nicely for that.

I'll add some improvements to the test and afterwards I'll open the PR to be merged.

Thx for the feedback

[trm217]

@pacocoursey I added a test-suite for the forcedTheme prop, however I am not completely sure if I used it the right way.
Am I correct to assume that I would have to use the forcedTheme value returned by the useTheme hook on the page that has a forced theme?
I was expecting the theme value returned by the hook to be equal to the forcedTheme... 🤔

[trm217]

@pacocoursey Would it be of interest to run the tests on every PR?
Perhaps it would be helpful to set two conditions for a PR to be merge: 1. All test-cases must be successful. 2. The code-coverage can not decrease below a given threshold.
If you could use some help with creating GitHub-actions feel free to contact me, I'd gladly help with that :)

[pacocoursey]

I was expecting the theme value returned by the hook to be equal to the forcedTheme

No, currently the hook will return whatever the active theme is (generally the UI should reflect it), then forcedTheme is returned as it's own value.

Would it be of interest to run the tests on every PR?

Yeah, for sure! I'll merge this and set this up to run in GH actions on every PR as a required step.

[trm217]

Good stuff! Thanks for the pleasant conversations 👍🏻