Introduce some Jest tests for the user interface

[jrgriffiniii]

Currently there are no functional tests which address JavaScript behavior for the application. Perhaps using the Jest framework for the application could ensure that the UI behaves properly in the browser.

Some behavior worth testing might be:

Dropdowns on the search results interface

Modal dialogues on the item show page

[jrgriffiniii]

This is my shameless way of using the workshop to advance geoblacklight/geoblacklight#680. I am not certain exactly how to best integrate Jest, so this will be a spike.

[jrgriffiniii]

I'm now seeing that one needs to use https://github.com/puppeteer/puppeteer/ in order to run headless Chrome tests with Jest. I can look at trying to get something up and running for this.

https://jestjs.io/docs/en/puppeteer also looks like a good resource.

[mejackreed]

So in geoblacklight/geoblacklight#680 I think we only need to run Jest for the JavaScript unit tests not the integration tests.

Recommended setup for Rails/GeoBlacklight/Blacklight integration tests are using rspec / capybara / webdrivers

[jrgriffiniii]

@irv I've been able to get things running locally with https://github.com/geoblacklight/workshop-app-2020/compare/jest-spike-jrgriffiniii - I can continue with looking to get GeoBlacklight running and seeded.

[mejackreed]

👏 Cool... looks like GeoBlacklight might be even simpler as we wouldn't need puppeteer just to support the JS unit tests