fix(37135): handle PrivateIdentifiers in isPropertyName (#37184)

Author: a-tarasyuk

src/compiler/utilitiesPublic.ts

@@ -1815,6 +1815,7 @@ namespace ts {
     export function isPropertyName(node: Node): node is PropertyName {
         const kind = node.kind;
         return kind === SyntaxKind.Identifier
+            || kind === SyntaxKind.PrivateIdentifier
             || kind === SyntaxKind.StringLiteral
             || kind === SyntaxKind.NumericLiteral
             || kind === SyntaxKind.ComputedPropertyName;

src/testRunner/unittests/publicApi.ts

@@ -46,8 +46,16 @@ describe("Public APIs:: token to string", () => {
         assertDefinedTokenToString(ts.SyntaxKind.FirstKeyword, ts.SyntaxKind.LastKeyword);
     });
 });
+
 describe("Public APIs:: createPrivateIdentifier", () => {
     it("throws when name doesn't start with #", () => {
-            assert.throw(() => ts.createPrivateIdentifier("not"), "Debug Failure. First character of private identifier must be #: not");
+        assert.throw(() => ts.createPrivateIdentifier("not"), "Debug Failure. First character of private identifier must be #: not");
+    });
+});
+
+describe("Public APIs:: isPropertyName", () => {
+    it("checks if a PrivateIdentifier is a valid property name", () => {
+        const prop = ts.createPrivateIdentifier("#foo");
+        assert.isTrue(ts.isPropertyName(prop), "PrivateIdentifier must be a valid property name.");
     });
 });