Add coverage script for truffle experiment

[cgewecke]

solidity-coverage 559

Hi @elenadimitrova.

PR adds a draft script to run coverage.

Good news

• It compiles additively, runs the tests and generates a report

Bad news

• ~170 tests fail
  • A few calls in the tests use hard coded gasLimits - these could be a problem
  • It's possible I misconfigured the ganache client (see providerOptions in .solcover.js)
• Legacy files compilation seems to hang forever (skipped those)
• Script file not linted (sorry)
• Migrations are deleted for now...

Other

• I disabled docker compilation in the coverage script because it seems super slow or broken - maybe truffle 2005 was never really fixed

But...think this is part-way there and a baseline for figuring out what further problems there might be.

Just lmk whatever questions you have / issues you discover.

[elenadimitrova]

Thanks a lot for this work @cgewecke 🎉 ❤️ I'm really happy for the good news and not worried about the bad news because:

• The failing tests are due to ganache-accounts.json not being generated in the coverage context. I've updated the providerOptions to do that.
• The legacy files compilation I've managed to solve in a commit I've not yet pushed on the main branch so that's not a problem as well.
• Not linting the script files is hardly bad news :)
• We are not using Migrations so I won't miss it.

I can't push to this fork so merging as-is (only 2 failing tests remain to be sorted) and picking the fixes above in main branch.

[cgewecke]

Ok awesome!