Allow passing mocha params in hardhat test command

[jmendiola222]

Describe the feature

There's been many requests for supporting particular params to mocha, either by config file and specially command. But most of them where stale closed, I think there is good evidence of this being useful on a variety of cases:

#1116
#2572
#2502
#2316
#1242
etc

My particular case, is the inability of using --invert while doing a --grep filter.

> hardhat test  --grep /.*CI.*/i --invert

Error HH305: Unrecognized param --invert

Refs: https://mochajs.org/api/mocha#invert

Search terms

mocha params test invert grep arguments

[fvictorio]

Hi @jmendiola222, thanks for this. You are right that this would be extremely useful. The problem is that, the way Hardhat's argument parser works right now, we need to add a new specific param for each Mocha param we want to support.

I think the best way to do this would be to first have support for -- in our tasks. I opened #4314 to track that. If we had that, then we could support something like this:

hh test -- --grep foo --invert

And the test task wouldn't need to explicitly support the invert flag.

[jmendiola222]

I'm not into the internals of hardhat implementation, so I can't tell if your proposal is in fact the best approach, but it certainly sounds reasonable. Thanks.