ci: add Codecov to check test coverage

[phm07]

No description provided.

[codecov]

Welcome to Codecov 🎉

Once merged to your default branch, Codecov will compare your coverage reports and display the results in this comment.

Thanks for integrating Codecov - We've got you covered ☂️

[apricote]

Could we add this to our existing test runs?

cli/.github/workflows/ci.yml

Line 43 in 1143e07

run: go test -v -race ./...

[jooola]

If I remember correctly, codecov will fail the pipelines if the coverage status checks fail, e.g. coverage is less than 80%.

Maybe we want to wait a bit before we enable such check to make such we actually have the required coverage.

See:
https://docs.codecov.com/docs/commit-status#project-status
https://docs.codecov.com/docs/commit-status#patch-status

Also, we might need to enable the carryforward flags, but I am not sure if we have split tests in the CLI (unit/e2e) ?

https://docs.codecov.com/docs/carryforward-flags

Maybe we can start with codecov.yml:

---
coverage:
  status:
    project: off # Or on is we have enough covrage ?
    patch: off

[apricote]

As far as I understood Codecov, Carryforward Flags are for setups where you only run a subset of tests (eg. only for changed files). We always run all tests. For different test suites you would use "flags": https://github.com/apricote/Listory/blob/25b738a246d380f1c526eb1de01cd146b0b3237f/.github/workflows/ci.yaml#L27

RE Status Checks, I would also prefer not to enable them. But I think we can do this organization wide at https://app.codecov.io/account/gh/hetznercloud/yaml/ instead of copying this in every repo.