Hardhat-network-helpers loadFixture is not working when running coverage

[Amxx]

Version of Hardhat

2.18.0

What happened?

See sc-forks/solidity-coverage#819

Minimal reproduction steps

See sc-forks/solidity-coverage#819

Search terms

chai fixture coverage

[cgewecke]

The companion issue for this at solidity-coverage has been resolved & the test helpers seem to work ok. See sc-forks/solidity-coverage#819 (comment) for details.

[fvictorio]

Sorry, I'm not sure if there's something we need to do here?

[Amxx]

The companion issue for this at solidity-coverage has been resolved & the test helpers seem to work ok.

I would disagree with that. Solidity-coverage not properly handling the hardhat env extension is a major drawback that can't simply be ignored.
Not sure anything should be done at the hardhat level though.

[cgewecke]

I would disagree with that. Solidity-coverage not properly handling the hardhat env extension is a major drawback that can't simply be ignored.

For more context I think the problem was caused by:

• using extendEnv to cache signers from the initial provider instantiated by hardhat
• solidity-coverage creating a new provider (and losing a relationship to the cached accounts)

It's kind of related to #1374 and #3491 although there are places in Hardhat itself (notably hardhat_reset) where the provider is recreated and it's possible doing this kind of stuff in extendEnv would run into trouble there too? Not certain.

Ideally the coverage tool would be entirely passive, rely on source-maps & a tracer api, and never touch the provider. This is difficult to get right though (for example, see Foundry coverage issues