fix(2536): avoid unsafe cast in documentHighlight parent function lookup (#2538)

Author: a-tarasyuk

internal/fourslash/tests/documentHighlightYield_test.go

@@ -0,0 +1,27 @@
+package fourslash_test
+
+import (
+	"testing"
+
+	"github.com/microsoft/typescript-go/internal/fourslash"
+	"github.com/microsoft/typescript-go/internal/testutil"
+)
+
+func TestDocumentHighlightYield(t *testing.T) {
+	t.Parallel()
+
+	defer testutil.RecoverAndFail(t, "Panic on fourslash test")
+	const content = `
+// @Filename: /a.ts
+class C {
+  async *[Symbol.asyncIterator]() {
+    [|yield|] {
+		type: 'type',
+	};
+  }
+}
+`
+	f, done := fourslash.NewFourslash(t, nil /*capabilities*/, content)
+	defer done()
+	f.VerifyBaselineDocumentHighlights(t, nil /*preferences*/, f.Ranges()[0])
+}

internal/ls/documenthighlights.go

@@ -577,7 +577,7 @@ func getAsyncAndAwaitOccurrences(node *ast.Node, sourceFile *ast.SourceFile) []*
 }
 
 func getYieldOccurrences(node *ast.Node, sourceFile *ast.SourceFile) []*ast.Node {
-	parentFunc := ast.FindAncestor(node.Parent, ast.IsFunctionLike).AsFunctionDeclaration()
+	parentFunc := ast.FindAncestor(node.Parent, ast.IsFunctionLike)
 	if parentFunc == nil {
 		return nil
 	}

testdata/baselines/reference/fourslash/documentHighlights/documentHighlightYield.baseline.jsonc

@@ -0,0 +1,10 @@
+// === documentHighlights ===
+// === /a.ts ===
+// class C {
+//   async *[Symbol.asyncIterator]() {
+//     /*HIGHLIGHTS*/[|yield|] {
+// 		type: 'type',
+// 	};
+//   }
+// }
+//