Add TOML cheatcode support

[zerosnacks]

Motivation

Closes #4808

Implements TOML cheatcode support equivalent to JSON cheatcode support

Solution

The implementation is a thin serialisation / deserialisation layer to convert between TOML to JSON. Internally it re-uses the existing serialized_jsons state. Has feature parity with JSON cheatcodes people are already familiar with.

Implements the following new cheatcodes:

• parseToml(string)
• parseToml(string,key) (key support!)
• All coercion cheatcodes (e.g. parseTomlUint(string,key)).
• writeToml(string,path)
• writeToml(string,path,key)

Re-uses JSON's non-prefixed serialize* methods as they operate on the serialized_jsons state.

Special case is: keyExistsToml(string,key) of which the equivalent is keyExists(string,key) in JSON (introduced in #5431). This was chosen to introduce no breaking changes.

Whilst this approach has some (minor) overhead it was chosen to limit complexity, increase maintainability, avoid breaking changes and achieve feature parity (including paths through jsonpath_lib of which no equivalent TOML library exists).

The test suite is a modified version of Json.t.sol. A possible improvement could be a shared abstraction of the two tests but I consider that to be out of scope for this PR.

At-merge PR:

• Documentation in foundry-book: Add TOML cheatcode documentation book#1133

Post-merge PR:

• Add upstream support to forge-std for the proposed cheatcodes: Add TOML cheatcode support forge-std#518

Known limitations:

• Currently the conversion from JSON string to TOML datetime is not handled as it would require a Regex match in a likely hot path for something that is highly uncommon.

[mds1]

Why do we need a keyExistsToml instead of reusing the keyExists method? Assuming we can't reuse them, we can keep keyExists for backwards compatibility but probably should also add a keyExistsJson alias and deprecate/remove the ambiguous keyExists at some point

[zerosnacks]

Good point, I'm in favor.

I don't see an elegant way of reusing the keyExists method without introducing brittle complexity (like a Regex). Would rather opt for explicit naming.

I did do a brief search on Github to see the impact and it should be relatively limited: https://github.com/search?q=vm.keyExists&type=code but we would still need an elegant way of issuing a deprecation message and schedule a removal. I'm unfamiliar with that process.

Happy to add it to this PR or open a separate one.

[mds1]

I'd say we make the change in this PR. In the past we've used console.logs to surface warnings about cheats being deprecated. That was in forge-std though, presumably we can do the same thing here by inserting the required call to the console address in the cheat implementation. But will defer to @DaniPopes @klkvr and co. on how they prefer to do this

[klkvr]

I don't think there is an easy way to log stuff directly from cheatcode impls rn, I've looked into it when working on native asserts. However, refactoring cheats/logging logic to support this is not hard but probably big enough to be out of scope for this PR

We already have cheat categories which should emit warnings, so we can probably just implement this logic and warn users about deprecated cheats (keyExists would be the only one for now I believe)

[zerosnacks]

I've opted for adding the keyExistsJson alias and marked keyExists with the Deprecated status. I've also added a comment in a few places marking the deprecation.

I've added a bug report for the emitting of warnings and errors here: #7323 so it can be picked up in a different PR.

[DaniPopes]

Approach LGTM, just a few questions.

[mattsse]

test look good!

ptal at cheatcode impl @DaniPopes @klkvr

[mattsse]

do we have a test for this table?

[zerosnacks]

Yes we do here, the test specifically covers the writing aspect:

foundry/testdata/cheats/Toml.t.sol

Lines 259 to 270 in 493c615

	function test_serializeNotSimpleToml() public {
	string memory json3 = "json3";
	string memory path = "fixtures/Toml/write_complex_test.toml";
	vm.serializeUint(json3, "a", uint256(123));
	string memory semiFinal = vm.serializeString(json3, "b", "test");
	string memory finalJson = vm.serializeString(json3, "c", semiFinal);
	console.log(finalJson);
	vm.writeToml(finalJson, path);
	string memory toml = vm.readFile(path);
	bytes memory data = vm.parseToml(toml);
	notSimpleJson memory decodedData = abi.decode(data, (notSimpleJson));
	}

[DaniPopes]

LGTM

[mattsse]

lgtm
send it @zerosnacks