Change error message in frontier to mimic ethereum

[joelamouche]

Motivation

I was testing contract calls and the error messages were slightly different than expected:
Frontier reverts say: 'evm revert: Reverted' when a regular ethereum blockchain would say 'VM Exception while processing transaction: revert'

Changing the Error message would allow devs to reuse ethereum tests for frontier based tests.

Suggested Solution

Just a slight change in error message

Alternatives

It's not a big deal but it would allow devs to reuse tests from ethereum to Frontier

[tgmichel]

I think this is a good idea, however, there are several variants for the revert message from what I read. I.e. including decoded revert reason from solidity explicit revert calls.

• VM Exception while processing transaction: revert
• VM Exception while processing transaction: revert {decoded revert reason}
• execution reverted: {decoded revert reason} (For Infura MainNet, Roptsen.. here)
• VM execution error. (For Infura Kovan here). This call also includes Revert {encoded revert reason} in the data field.

So I'd say we want this to be configurable (actually for all ExitReason messages), including optional pre-decoded revert reasons that can also be part of ad-hoc tests in case the Dapp makes heavy use of explicit reverts in their code.

[joelamouche]

I think the default should be VM Exception while processing transaction: revert {decoded revert reason}

[joelamouche]

I still get the old error code when I run the tests in https://github.com/PureStake/moonbeam/pull/124/files @tgmichel

[joelamouche]

oh wait but this is frontier