feat(forge fmt): add --fix-checksum flag to automatically fix invalid checksum addresses in contracts

[sambacha]

Component

Forge

Describe the feature you would like

fmt checksum would automatically fix checksum issues:

Motivating Case

0x7a250d5630B4cf539739df2c5dacb4c659f2488d

0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D

Existing Error

Error: Compiler run failed:
Error (9429): This looks like an address but has an invalid checksum. Correct checksummed address: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48". If this is not used as an address, please prepend '00'. For more information please see https://docs.soliditylang.org/en/develop/types.html#address-literals

Additional context

When fmt checksum fixes any issue it SHOULD alert user that it fixed checksum issue and that used as an address, please prepend '00'. in case otherwise

[Mouzayan]

can i get assigned to this one?

[zerosnacks]

@Mouzayan assigned!

[Mouzayan]

I’m currently working on this issue, to track my progress see here.

[zerosnacks]

Great! Tip: you can use Alloy Core's Address to transform the address into a checksummed version.

[zerosnacks]

It can be useful to look at the Parsed version of the source code, you can find the implementation here: https://github.com/foundry-rs/foundry/blob/master/crates/fmt/src/helpers.rs.

You can also have a look at

foundry/crates/fmt/src/formatter.rs

Lines 2363 to 2364 in 7825a06

	Type::Address => write_chunk!(self, loc.start(), "address")?,
	Type::AddressPayable => write_chunk!(self, loc.start(), "address payable")?,

and

foundry/crates/fmt/src/formatter.rs

Lines 2433 to 2442 in 7825a06

	Expression::HexNumberLiteral(loc, val, unit) => {
	// ref: https://docs.soliditylang.org/en/latest/types.html?highlight=address%20literal#address-literals
	let val = if val.len() == 42 {
	Address::from_str(val).expect("").to_string()
	} else {
	val.to_owned()
	};
	write_chunk!(self, loc.start(), loc.end(), "{val}")?;
	self.write_unit(unit)?;
	}

and how they enforce specific formatting rules

[DaniPopes]

As you can see above, addresses are already checksummed in the Address... .to_string() :

foundry/crates/fmt/src/formatter.rs

Lines 2433 to 2442 in 7825a06

	Expression::HexNumberLiteral(loc, val, unit) => {
	// ref: https://docs.soliditylang.org/en/latest/types.html?highlight=address%20literal#address-literals
	let val = if val.len() == 42 {
	Address::from_str(val).expect("").to_string()
	} else {
	val.to_owned()
	};
	write_chunk!(self, loc.start(), loc.end(), "{val}")?;
	self.write_unit(unit)?;
	}

You can try it out for yourself:

function f() {
    address a = 0x7a250d5630B4cf539739df2c5dacb4c659f2488d;
}

$ forge build
Error (9429): This looks like an address but has an invalid checksum. ...
$ forge fmt
$ forge build
# OK