Convert Frontend Test Runner from Minitest to RSpec

[KludgeKML]

⚠️ This repo is Continuously Deployed: make sure you follow the guidance ⚠️

NB: Currently failing checks because it's expecting a minitest check - as long as that's the only failure it is safe to merge but we will need to update the settings

What

Replace Frontend's existing minitest test suite with the equivalent in RSpec.

Why

RSpec is our standard, and we want to merge some smaller apps (using RSpec test suites) into Frontend. We have decided it's better to rewrite the larger app to conform to our standard than move the smaller app in the other direction.

Trello card

How

We do the bulk of the conversion using a fork of the minitest_to_rspec gem; then tidy up the code with rubocop before manually tweaking the remaining tests that don't run. Finally we compare coverage to ensure that we have the same between the versions.

Coverage

Line coverage is slightly improved (97.8% -> 97.94%)

Style decisions I have made (and can unmake!)

In tidying up the autogenerated specs, I've made a bunch of style decisions that aren't really covered by rubocop but which I've tried to maintain to keep the new files consistent with other spec tests (we don't have a perfect consistency in other apps, but there's a rough consensus). I'm not married to these decisions, so feel free to comment on them and we can update the files:

• requires at the top of _spec files don't have parentheses around their parameters
• describe/context/it blocks don't have parentheses around their parameter
• describe blocks at the top of a file are namespaced explicitly (ie RSpec.describe instead of just describe)
• includes at the top of a describe block don't have parentheses around their parameters
• expect does have parentheses (if not a block), and so do the matches, but #to and #not_to don't.
• There are blank links between contexts and its.
• Inside an it block, I try to leave a blank line between setup and the first expectation
• I use #describe for the top block in a file, and for any block that is a named method, #context otherwise.
• I don't have separate assertions for "check for a status of redirect" and "check the current location" - expect(response).to redirect_to() covers both of these tests.

Test Type Conversion

The current idiom is to prefer system spec over feature specs, so all feature tests have been converted to system specs, and request specs over controller specs, so all controller tests have been converted to request specs. Note that in a few cases this has meant a slight adjustment to the tests (some previous controller tests were not suitable for request specs, so have been moved into the system specs for the related feature, and some tests have been simplified as above).

In addition, I've moved tests into directories that reflect their test types, allowing us to avoid explicit test types with teh config.infer_spec_type_from_file_location! RSpec directive - so some of the previous unit tests are moved out into /models and /helpers. Ideally no test types should be added explicitly. The sole exception to this is components, since by convention we tend to put those in /components, and they need to be a mixture of view types (the actual component tests) and default type (the all_components code).

Decisions I have avoided making

I haven't closely examined each test to determine whether it's actually worthwhile as a test. Some of the reviewers pointed out tests that are not great, I've dealt with them. But don't take this PR as an endorsement of the quality of individual tests.

[leenagupte]

This is looking good. And the tests are running 🎉

A couple of things I'm not sure about is the nesting of the components helper modules. Other thoughts / comments are inline.

[hannako]

END OF AN ERA!

Well done on not giving up in the face of 8 thousand review comments 💪

[KludgeKML]

Those 8 thousand review comments helped it move from a poorly formed mass of clay into a fine china pot (with a few blemishes). Thanks @hannako and @leenagupte for all the suggestions!