Exclude reparsed nodes from inlay hints

[ahejlsberg]

Fixes #2460.

[Copilot]

Pull request overview

This PR prevents textDocument/inlayHint from crashing when it encounters reparsed AST nodes, addressing issue #2460. The change aligns inlay hint traversal with how other language service features treat reparsed nodes.

Changes:

• Update inlayHintState.visit to skip nodes marked with ast.NodeFlagsReparsed, avoiding attempts to create tokens for reparsed nodes and thus preventing the panic in SourceFile.GetOrCreateToken.

[Copilot]

This change fixes a crash on reparsed function expressions, but there is no new regression test covering the scenario from issue #2460 (inlay hints over a reparsed function expression). Given the existing fourslash-based inlay hint tests (e.g. inlayHintsCrash1, inlayHintsTupleTypeCrash), please add a similar fourslash test that exercises a reparsed function expression so future changes don’t reintroduce this panic without being caught by CI.

[ahejlsberg]

I don't think we need a regression test.

[DanielRosenwasser]

@copilot please add the regression test from #2460 (comment) in another PR

package fourslash_test

import (
	"testing"

	"github.com/microsoft/typescript-go/internal/fourslash"
	"github.com/microsoft/typescript-go/internal/ls/lsutil"
	"github.com/microsoft/typescript-go/internal/testutil"
)

func TestInlayHintsCrash(t *testing.T) {
	t.Parallel()

	defer testutil.RecoverAndFail(t, "Panic on fourslash test")
	const content = `
// @allowJs: true
// @checkJs: true

// @Filename: /a.js
module.exports = function () {
  return 1;
};
`

	f, done := fourslash.NewFourslash(t, nil /*capabilities*/, content)
	defer done()
	f.VerifyBaselineInlayHints(t, nil /*span*/, &lsutil.UserPreferences{InlayHints: lsutil.InlayHintsPreferences{
		IncludeInlayFunctionLikeReturnTypeHints: true,
		IncludeInlayFunctionParameterTypeHints:  true,
	}})
}

and verify that it fails if the fix here is not applied.

[Copilot]

@DanielRosenwasser I've opened a new pull request, #2595, to work on those changes. Once the pull request is ready, I'll request review from you.