Coverage: Verify that LCOV reporter is working

[onbjerg]

We need to verify that the LCOV reporter does not output a malformed report - genhtml did not work for me, but I'm unsure if that is expected since it was made for C LCOV reports, so I am looking for other ways to test.

[onbjerg]

I just verified this, although it did highlight some odd behavior with forge coverage I am tracking down/finding explanations for.

To reproduce:

forge coverage --report lcov
genhtml -o report lcov.info

(note: this spams your project folder with a bunch of HTML and CSS so probably not the wisest to do)

See below for an example genhtml run on an lcov.info generated by Forge.

Some observations:

• I have not created a line item for function definitions, so this info is not surfaced in the LCOV report (i.e. you can't see how many times a function was called in the source view, but it does work in the "functions" view, see below)
• branchRequire looks like it should given I test it 2 times, once for true/false.
• Same for branchAssert
• Same for branchIf
• For oddEven:
  • The first two lines look OK, given they are only executed once - but it is unclear if we should report how many times the loop condition is run instead of how many times you "enter" the loop?
  • I am not entirely sure why the if statement in the for loop shows 12 executions instead of 10
  • Similarly, I am not sure why the two statements in the for loop show up as executed 6 and 7 times instead of 5 each.

I will go over them in a bit more detail to figure out what's going on and open up relevant issues.

Example report

Source view

Functions view