LSP: Jump to the function name

[shinichy]

Improved the "Go to Definition" command to jump to the function name instead of the beginning of the function keyword.

Example:

function foo() {
   ...
}

foo(); // "Go to Definition" jumps to `foo` instead of `function`.

[shinichy]

I tried to port the logic from src/services/goToDefinition.ts in the TypeScript repository.

[Copilot]

Pull Request Overview

This PR improves the “Go to Definition” command so that it now jumps directly to a function’s name instead of its leading keyword. Key changes include:

• Updating the definition lookup in internal/ls/definition.go to focus on the function name.
• Renaming several helper functions to exported versions (e.g., GetResolvedSignature, IsCallLikeExpression) for consistency.
• Adding new utility functions in internal/ast/utilities.go to support the enhanced navigation.

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
internal/ls/definition.go	Refactored definition location logic and added helper functions.
internal/checker/utilities.go	Renamed and added exported helper functions for signature checks.
internal/checker/jsx.go	Updated signature resolution to use exported helper functions.
internal/checker/flow.go	Updated calls to use the exported GetResolvedSignature function.
internal/checker/checker.go	Replaced internal function calls with their exported counterparts.
internal/ast/utilities.go	Added a utility to determine property access context.

Comments suppressed due to low confidence (4)

internal/ls/definition.go:19

• [nitpick] Consider renaming 'tryGetSignatureDeclaration' to better convey its intent (e.g., 'getSignatureDeclaration') if it always returns a declaration or nil.

calledDeclaration := tryGetSignatureDeclaration(checker, node)

internal/checker/utilities.go:1297

• Ensure that the change to an exported function name is accompanied by updated documentation comments to clarify its usage.

func IsCallLikeExpression(node *ast.Node) bool {

internal/checker/checker.go:7904

• [nitpick] Verify that all calls to the renamed 'GetResolvedSignature' are updated consistently and that its behavior is properly documented.

func (c *Checker) GetResolvedSignature(node *ast.Node, candidatesOutArray *[]*Signature, checkMode CheckMode) *Signature {

internal/ast/utilities.go:2654

• [nitpick] Add a documentation comment for 'IsRightSideOfPropertyAccess' to clearly describe its purpose and usage in the codebase.

func IsRightSideOfPropertyAccess(node *Node) bool {

[sandersn]

@iisaduan is working on find-all-refs, so she may have already looked at this code.

Should some tests change? I'm not sure if fourslash tests are available yet.

[iisaduan]

It's pretty separate from the find all refs work I've been doing, so there's no duplication. But the PR probably should update tests, so we have some sort of reference for what has been ported already/what we expect to work

[iisaduan]

I could probably test this with my find all refs testing, but it's not quite ready yet

[shinichy]

It's good to know that there's no duplication, as that's something I was concerned about since your team seems to be actively working on the ls package. I'll also try to add a test.