LibJS: Implement Object.prototype.propertyIsEnumerable

Spec: https://tc39.es/ecma262/#sec-object.prototype.propertyisenumerable This is used by core-js, which is used by frameworks such as Vue.
Author: https://github.com/Lubrsi Commit: 200c7572b7 Pull-request: https://github.com/SerenityOS/serenity/pull/4524 Reviewed-by: https://github.com/linusg ✅
2025-07-29 04:09:13 +00:00 · 2020-12-24 17:51:28 +00:00 · 2020-12-24 17:51:28 +00:00 · 200c7572b7 · 2024-07-19 00:37:58 +09:00
commit 200c7572b7
parent d46de3aeb4
4 changed files with 32 additions and 0 deletions
--- a/Libraries/LibJS/Tests/builtins/Object/Object.prototype.propertyIsEnumerable.js
+++ b/Libraries/LibJS/Tests/builtins/Object/Object.prototype.propertyIsEnumerable.js
@ -0,0 +1,15 @@
+test("basic functionality", () => {
+    var o = {};
+
+    o.foo = 1;
+    expect(o.propertyIsEnumerable("foo")).toBeTrue();
+    expect(o.propertyIsEnumerable("bar")).toBeFalse();
+    expect(o.propertyIsEnumerable()).toBeFalse();
+    expect(o.propertyIsEnumerable(undefined)).toBeFalse();
+
+    o.undefined = 2;
+    expect(o.propertyIsEnumerable()).toBeTrue();
+    expect(o.propertyIsEnumerable(undefined)).toBeTrue();
+
+    expect(globalThis.propertyIsEnumerable("globalThis")).toBeFalse();
+});