Add test coverage reporting (and uploading to codecov)?

[liamsi]

We could look into https://github.com/libra/libra/blob/ead737947aa59499ea75b5a926d221ac089ce803/.circleci/config.yml#L51-L58
and
https://github.com/libra/libra/blob/ead737947aa59499ea75b5a926d221ac089ce803/scripts/coverage_report.sh#L97-L104
for a good example how to do this.

[tarcieri]

You might also check out Tarpaulin

[liamsi]

Thanks, will look into it, too. Would Tarpulin be your tool of choice here?

[tarcieri]

It's the main one I've worked with in the past. I know some people have had issues with it, but it seems fairly popular.

[liamsi]

Just to visualize this a little; this is output generated via grcov (generated on branch ismail/light_cleanup, commit 7012553)

file view:

Both Tarpulin and grcov can report on the diff (locally and via coverall.io for instance)
(example project using Tarpulin: https://coveralls.io/github/xd009642/keygraph-rs?branch=master)

Tarpulin doesn't run natively on Macs but docker images are provided. In general Tarpulin seems a bit easier to use to me.

P.S. IntelliJ (never disappoints me and) has test coverage reporting integrated into the IDE. They use grcov apparently. I have a slight preference for grcov as numbers reported by the CI will match my local way of detecting test-coverage but that's probably not the best reason :-D

[liamsi]

Closed via #134 (with grcov; if need arises we can switch to another code coverage tool)
Another issue deals with CI #135