feat(cheatcodes): add vm.getSelectors cheatcode

[zacharyftw]

Motivation

Retrieving function selectors currently requires ffi + forge inspect or manually parsing artifact JSON with vm.readFile. Both are clunky and clutter test traces. Closes #11484

Solution

Add vm.getSelectors(string calldata artifactPath) cheatcode that returns bytes4[] of all function selectors from a contract's ABI. Supports the same artifact path formats as vm.getCode.

PR Checklist

• Added Tests
• Added Documentation
• Breaking changes

[Copilot]

Pull request overview

Adds a new filesystem cheatcode to extract function selectors directly from compiled contract artifacts, reducing the need for ffi/forge inspect workflows in Solidity tests.

Changes:

• Introduces vm.getSelectors(string artifactPath) returning bytes4[] from an artifact ABI.
• Implements artifact ABI resolution in Rust cheatcodes execution and wires the new cheatcode into the spec/assets.
• Adds Solidity tests covering several artifact path formats.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
testdata/utils/Vm.sol	Exposes the new getSelectors function on the Vm interface used by tests.
testdata/default/cheats/GetSelectors.t.sol	Adds a new cheatcode test suite for selector retrieval via different path forms.
crates/cheatcodes/src/fs.rs	Implements the getSelectors cheatcode and artifact-ABI lookup helper.
crates/cheatcodes/spec/src/vm.rs	Updates the cheatcode spec interface/docs for getSelectors.
crates/cheatcodes/assets/cheatcodes.json	Registers getSelectors in the generated cheatcodes metadata (signature/selector/docs).

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

get_artifact_abi largely duplicates the path parsing + artifact selection logic from get_artifact_code. This makes it easy for the two to drift (e.g., if a new path format is added to one but not the other). Consider extracting the shared parsing/matching into a helper that returns the resolved artifact (or resolved artifact path), then have get_artifact_code and get_artifact_abi build on that.

[Copilot]

The test suite covers name, name+version, and full-path inputs, but it doesn’t exercise the .json artifact-path variant mentioned in the docs, nor any failure modes (e.g., unknown contract name / wrong version) to assert the revert message. Adding at least one .json-path test and one negative test would help ensure the path resolution and error behavior stay stable.

Suggested change

	function testGetSelectorsByJsonArtifactPath() public {
	bytes4[] memory selectors = vm.getSelectors("cheats/GetSelectors.t.sol/TargetContract.json");
	assertEq(selectors.length, 3, "should return 3 selectors");
	assertTrue(_contains(selectors, TargetContract.foo.selector), "should contain foo selector");
	assertTrue(_contains(selectors, TargetContract.bar.selector), "should contain bar selector");
	assertTrue(_contains(selectors, TargetContract.baz.selector), "should contain baz selector");
	}
	function testGetSelectorsUnknownContractReverts() public {
	vm.expectRevert();
	vm.getSelectors("UnknownTargetContract");
	}

[mattsse]

not opposed to this but I think we should avoid adding another standalone artifact parsing fn

[mattsse]

maybe we can unify this with existing function with get_artifact_code

[zacharyftw]

@mattsse i have dropped the dup fn 👍🏽

[mablr]

Sgtm, pending @mattsse's approval.