fix: gethify eth call errors (#2133)

[MicaiahReid]

Before this change, errors from eth_call were formatted in our "non-standard" vmErrorsOnRPCResponse format, which uses the error's data property to store some extra helpful information (program counter, hash, etc.):

{
   "error": {
     "message": "...",
     "code": ...
     "data": {
          ... bunch of props, like `hash` and `programCounter`...
         "result": "<raw revert hex string>" <---- this moves (See below)
     }
   } 
}

Now, the error's data property only contains the raw revert hex string, which should more closely match real node's error handling:

{
   "error": {
     "message": "...", // <- we'll change the message
     "code": ...
     "data": "<raw revert hex string>"  <---- new home
   } 
}

Our hope is that this will allow users to remove any conditionals handling errors differently between Ganache and real Ethereum nodes.

[fabianorodrigo]

Guys,
I have a doubt about this changes implemented on v7.0.1.

I'm using the package @openzeppelin/test-helpers in my unit tests, where I have oracles like this:

await expectRevert( gameContract.bet(score, betTokenAmount, { from: bettor, }), "ERC20: transfer amount exceeds allowance" );
Won't Ganache give me that message I passed to revert inside my contract?

Sorry if I misunderstand. It's because when I run run the above test on Ganache v2.5.4 it works/passes, but after upgrading to v7.0.1 it's failing:

`
Wrong kind of exception received
+ expected - actual

  -Transaction: 0x3dfa34902aaceb3fd6e7176180d65bc9c0b7ec664ddad54c5700ab2f42d6214c exited with an error (status 0). 
  -     Please check that the transaction:
  -     - satisfies all conditions set by Solidity `require` statements.
  -     - does not trigger a Solidity `revert` statement.
  +ERC20: transfer amount exceeds allowance`

[davidmurdoch]

@fabianorodrigo Have you updated your truffle version to the latest version?

[cds-amal]

hi @fabianorodrigo, you'll need to update to the latest version of truffle npm -g uninstall truffle && npm -g install truffle and your project tests should work. Note, I pushed a PR to align your tests with openzeppelin-test-helper documentation that you should review.

[fabianorodrigo]

@cds-amal ,
Thank you very much! I've already updated to Truffle v5.4.31 but after reading your answer I realized that it was at another workstation.
Now I updated Truffle and everything is fine.
Thanks!