Solidity Coverage returns 0%

[jeffywu]

I've been using this as a repo for my solidity project and it's been really helpful. Saw that solidity-coverage was added here but it returns 0% for me when I run it. Getting the same issue with the setup in my project as well. Wonder if you guys got it working?

> server:            http://127.0.0.1:8555
> ganache-core:      v2.8.0
> solidity-coverage: v0.7.1

Network Info
============
> port:    8555
> network: soliditycoverage


Instrumenting for coverage...
=============================

> Counter.sol
Compiling...
Downloading compiler version 0.6.2
Compiled 2 contracts successfully
All contracts have already been compiled, skipping compilation.


  Counter
    count up
      ✓ should count up (277ms)
    count down
      ✓ should fail (1051ms)
      ✓ should count down (188ms)


  3 passing (2s)

--------------|----------|----------|----------|----------|----------------|
File          |  % Stmts | % Branch |  % Funcs |  % Lines |Uncovered Lines |
--------------|----------|----------|----------|----------|----------------|
 contracts/   |        0 |        0 |        0 |        0 |                |
  Counter.sol |        0 |        0 |        0 |        0 |... 28,30,32,33 |
--------------|----------|----------|----------|----------|----------------|
All files     |        0 |        0 |        0 |        0 |                |
--------------|----------|----------|----------|----------|----------------|

> Istanbul reports written to ./coverage/ and ./coverage.json
> solidity-coverage cleaning up, shutting down ganache server

[jeffywu]

Looking at this and maybe I've set up some things wrong:
https://github.com/rhlsthrm/typescript-solidity-dev-starter-kit/pull/6/files

Will update if I get it resolved. Thanks.

[jeffywu]

Ok, the pull request was informative but I had a lot of stuff set up already so it took a bit of work to get everything where I needed it. Some things to note:

1. Waffle needs to be imported from @nomiclabs/buidler which this repo is doing properly but I was not.
2. When solidity-coverage runs it deploys different bytecode that is much larger than what the regular builds create. It took me a little while to figure this out since solidity-coverage also deletes its artifacts after it runs. I added in an if block and an environment variable to switch between the two artifacts depending on if I was running tests normally or coverage.

Not sure where to properly document this for others to find out, the solidity-coverage docs and the buidler docs weren't too helpful. I'm sure others will run into the same issue. I'll ping the devs there.