Vitest Pros:
* Automated failing test comments on github PRs
* A nice local UI with incremental testing when changing files (`yarn
test:ui`)
* Also nicely supported in all major IDEs, click to run test works (so
we won't miss what we had with jest).
* Works well with ESM
Vitest Cons:
* The ESBuild transformer vitest uses takes a little longer to transform
than our current SWC/jest setup, however, it is possible to setup SWC as
the transformer for vitest as well (though it only does one transform,
so we're paying ~7-10 seconds instead of ~ 2-3 seconds in transform
phase).
* Exposes how slow our tests are (tongue in cheek here)
We're migrating to ESM, which will allow us to import the latest
versions of our dependencies.
Co-Authored-By: Christopher Kolstad <chriswk@getunleash.io>
In this PR I integrate the Unleash React SDK with the Admin UI.
We also take advantage of Unleash Hosted Edge behind the scenes with
multiple regions to get the evaluations close to the end user.
## About the changes
Some of our metrics are not labeled correctly, one example is
`<base-path>/api/frontend/client/metrics` is labeled as
`/client/metrics`. We can see that in internal-backstage/prometheus:

This issue affects all endpoints that fail to validate the request body.
Also, endpoints that are rejected by the authorization-middleware or the
api-token-middleware are reported as `(hidden)`.
To gain more insights on our api usage but being protective of metrics
cardinality we're prefixing `(hidden)` with some well known base urls:
https://github.com/Unleash/unleash/pull/6400/files#diff-1ed998ca46ffc97c9c0d5d400bfd982dbffdb3004b78a230a8a38e7644eee9b6R17-R33
## How to reproduce:
Make an invalid call to metrics (e.g. stop set to null), then check
/internal-backstage/prometheus and find the 400 error. Expected to be at
`path="/api/client/metrics"` but will have `path=""`:
```shell
curl -H"Authorization: *:development.unleash-insecure-client-api-token" -H'Content-type: application/json' localhost:4242/api/client/metrics -d '{
"appName": "bash-test",
"instanceId": "application-name-dacb1234",
"environment": "development",
"bucket": {
"start": "2023-07-27T11:23:44Z",
"stop": null,
"toggles": {
"myCoolToggle": {
"yes": 25,
"no": 42,
"variants": {
"blue": 6,
"green": 15,
"red": 46
}
},
"myOtherToggle": {
"yes": 0,
"no": 100
}
}
}
}'
```