Hardhat migration

[TomAFrench]

Changelog:

• update all packages to their hardhat variant
• use hardhat-typechain rather than custom task for typechain types
• add hardhat-spdx-license-identifier
• resupport solidity-coverage (subject to Support HardHat  sc-forks/solidity-coverage#541)

[PaulRBerg]

Whoah, thanks for this dude! I'll test the integration as soon as solidity-coverage is available.

[TomAFrench]

Looks like solidity-coverage support is here.

[PaulRBerg]

Yeah this is on my to-do list.

[PaulRBerg]

It looks like there is a mismatched dependency:

hardhat-typechain@0.3.3" has incorrect peer dependency "typechain@^3.0.0"

I'll fix it myself and push to your branch.

[PaulRBerg]

One thing that I really don't like is including hardhat-spdx-license-identifier. It's an opinionated tool that doesn't add much value - the Solidity compiler would warn the user about the missing SPDX identifiers anyways.

It adds these superfluous logs when running the compile and coverage scripts:

Prepended SPDX License Identifier "WTFPL" to 0 sources.
Compiling 2 files with 0.7.4
Compilation finished successfully
Creating Typechain artifacts in directory typechain for target ethers-v5
Successfully generated Typechain artifacts!
Prepended SPDX License Identifier "WTFPL" to 0 sources.
Creating Typechain artifacts in directory typechain for target ethers-v5
Successfully generated Typechain artifacts!

[TomAFrench]

One thing that I really don't like is including hardhat-spdx-license-identifier. It's an opinionated tool that doesn't add much value - the Solidity compiler would warn the user about the missing SPDX identifiers anyways.

Fair enough. I find it useful but definitely see why others may feel otherwise.

Agree on the 0 sources messages though. May make a PR for that at some point

[PaulRBerg]

Yeah if they remove that message, happy to add it back.