Feat: Solidity Repl

[brockelmore]

Have seen a few requests for a solidity repl. This can be a tracking issue for the feature

Helpful things:

• https://github.com/tintinweb/solidity-shell
• https://github.com/raineorshine/solidity-repl

[transmissions11]

Omg would be so dope if it had all your contract abis loaded to go so you could do something like ERC20 token new ERC20() in the shell right away and just play around with it

[mattsse]

some thoughts after skimming solidity-shell's codebase

it appears an appropriate approach to this could be:

1. run a repl like https://github.com/kkawakam/rustyline, see also https://github.com/kpcyrd/sn0int for an example implementation
2. listen for user input
   a. if it's a solidity statement, inject that into a template contract, compile and deploy that
   b. if it's some math expr, inject that into a function, deploy and return the response after calling that template function
   c. else try to find a matching function that was previously deployed and call that

There's also TempProject now in ethers-solc which is probably helpful

If anyone would like to take this on, I'm happy to help

[transmissions11]

Can we persist variables? That’d be a dream

[mattsse]

totally, what I'm thinking is something like this:

pub struct SolRepl {
    /// this gives us the user input
    rl: Readline,
    /// this stores all previously evaluated user inputs, like vars, etc
    session: Session,
    /// the type that executes all the things
    sol: Sol,
}

struct Sol {
  /// the virtual project where we store all the things (perhaps not even necessary if we only use solc standard json input/output)
  project: TempProject,
  // stores all the deployed contracts/abis etc...
  state: SolState
}

then the actual repl would probably look something like:

loop {
 
 let input = self.rl.readline();
 let res = self.sol.execute(&line);
 println!("{}", res);
  }

[wilsoncusack]

Would love to see gas cost printed after evaluation :)

[mattsse]

closed via #3465