chore(site): Add unit tests, mocks

[presleyp]

This addresses part of #485.

• I extracted redirect functions and unit tested them. I moved them into utils so we can reuse them elsewhere if needed.
• In my attempt to test the login/redirect flow, I made some improvements to the testing setup (mocked more endpoints, moved the Router out of App so you can use a test router with it, made the mock entities have consistently named ids). But ultimately the test is not working and is taking longer than it's worth to figure out why, so I'm going to come back to it when we're further along.
• I happened across the fact that we had placeholders instead of labels in our sign in form and changed that for accessibility reasons. I'd like the tests to select the inputs by the labels but that also wasn't working.

[codecov]

Codecov Report

Merging #514 (a0eca97) into main (26d24f4) will decrease coverage by 0.13%.
The diff coverage is 28.20%.

@@            Coverage Diff             @@
##             main     #514      +/-   ##
==========================================
- Coverage   60.35%   60.22%   -0.14%     
==========================================
  Files         191      193       +2     
  Lines       10864    10875      +11     
  Branches       85       83       -2     
==========================================
- Hits         6557     6549       -8     
- Misses       3587     3603      +16     
- Partials      720      723       +3     

Flag	Coverage Δ
unittest-go-macos-latest	56.23% <ø> (+0.11%)	⬆️
unittest-go-ubuntu-latest	59.75% <ø> (-0.09%)	⬇️
unittest-go-windows-2022	55.94% <ø> (+0.03%)	⬆️
unittest-js	62.62% <28.20%> (-0.57%)	⬇️

Impacted Files	Coverage Δ
site/src/AppRouter.tsx	0.00% <0.00%> (ø)
site/src/api/index.ts	69.23% <ø> (+10.40%)	⬆️
site/src/app.tsx	0.00% <0.00%> (ø)
site/src/components/Page/RequireAuth.tsx	0.00% <0.00%> (ø)
site/src/components/SignIn/SignInForm.tsx	100.00% <ø> (ø)
site/src/test_helpers/handlers.ts	21.73% <0.00%> (-16.73%)	⬇️
site/src/pages/login.tsx	90.47% <100.00%> (+2.47%)	⬆️
site/src/test_helpers/entities.ts	100.00% <100.00%> (ø)
site/src/util/redirect.ts	100.00% <100.00%> (ø)
cli/config/file.go	67.64% <0.00%> (-8.83%)	⬇️
... and 4 more

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[greyscaled]

Change looks good to me, thanks for fixing the login page labels and improving the test setup. The questions I had were mostly related to the semantics in the mock rest responses, otherwise ✔️

[greyscaled]

Thinking out loud (non-blocking): Something that we lose/was nice in the prior implementation is a single entrypoint into the React application <App>. I think this PR is a step in the right direction and an improvement, so I don't think we need to optimize for this now, but I'd expect to see one component here eventually. I think a related problem is that we don't keep App thin right now, and can probably extract out the providers like in v1.

We can think on this later; I'm getting the thoughts out there, but don't want to block!

[presleyp]

Yeah I think the better way to do what I was trying to do is to split App into two components, one that has the router and providers, and one that has the routes. That way we could test the routes one with a test setup and keep Main simple.

[presleyp]

I just did that, what do you think? let me know if there's a better name!

[greyscaled]

I'm not sure if there's more work to do in the API mocks, but everything is looking good and those will be continually evolving as we go.

Great stuff!