From 4c3a415dc3247e6dc4b62baffd62c952d2b9e8f7 Mon Sep 17 00:00:00 2001
From: Matthew Olsson <matthewcolsson@gmail.com>
Date: Sun, 12 Jul 2020 12:51:12 -0700
Subject: [PATCH] LibJS: Add String Iterator tests

---
 .../LibJS/Tests/iterators/array-iterator.js   |  2 +-
 .../LibJS/Tests/iterators/string-iterator.js  | 48 +++++++++++++++++++
 2 files changed, 49 insertions(+), 1 deletion(-)
 create mode 100644 Libraries/LibJS/Tests/iterators/string-iterator.js

diff --git a/Libraries/LibJS/Tests/iterators/array-iterator.js b/Libraries/LibJS/Tests/iterators/array-iterator.js
index 8f02845ebe..92966d54d4 100644
--- a/Libraries/LibJS/Tests/iterators/array-iterator.js
+++ b/Libraries/LibJS/Tests/iterators/array-iterator.js
@@ -1,5 +1,5 @@
 test("length", () => {
-    expect(Array.prototype[Symbol.iterator].length).toBe(0);
+    expect(Array.prototype[Symbol.iterator]).toHaveLength(0);
 });
 
 test("@@toStringTag", () => {
diff --git a/Libraries/LibJS/Tests/iterators/string-iterator.js b/Libraries/LibJS/Tests/iterators/string-iterator.js
new file mode 100644
index 0000000000..379f6f05fc
--- /dev/null
+++ b/Libraries/LibJS/Tests/iterators/string-iterator.js
@@ -0,0 +1,48 @@
+test("length", () => {
+    expect(String.prototype[Symbol.iterator]).toHaveLength(0);
+});
+
+test("basic functionality", () => {
+    const s = "abcd";
+    const it = s[Symbol.iterator]();
+    expect(it.next()).toEqual({ value: "a", done: false });
+    expect(it.next()).toEqual({ value: "b", done: false });
+    expect(it.next()).toEqual({ value: "c", done: false });
+    expect(it.next()).toEqual({ value: "d", done: false });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+});
+
+test("casts |this| to string", () => {
+    const it = String.prototype[Symbol.iterator].call(45);
+    expect(it.next()).toEqual({ value: "4", done: false });
+    expect(it.next()).toEqual({ value: "5", done: false });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+
+    const it = String.prototype[Symbol.iterator].call(false);
+    expect(it.next()).toEqual({ value: "f", done: false });
+    expect(it.next()).toEqual({ value: "a", done: false });
+    expect(it.next()).toEqual({ value: "l", done: false });
+    expect(it.next()).toEqual({ value: "s", done: false });
+    expect(it.next()).toEqual({ value: "e", done: false });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+
+    expect(() => {
+        String.prototype[Symbol.iterator].call(null);
+    }).toThrowWithMessage(TypeError, "ToObject on null or undefined");
+    expect(() => {
+        String.prototype[Symbol.iterator].call(undefined);
+    }).toThrowWithMessage(TypeError, "ToObject on null or undefined");
+});
+
+test("utf8 compatible", () => {
+    const it = "ab\u{1f41e}cde"[Symbol.iterator]();
+    expect(it.next()).toEqual({ value: "a", done: false });
+    expect(it.next()).toEqual({ value: "b", done: false });
+    expect(it.next()).toEqual({ value: "🐞", done: false });
+    expect(it.next()).toEqual({ value: "c", done: false });
+    expect(it.next()).toEqual({ value: "d", done: false });
+    expect(it.next()).toEqual({ value: "e", done: false });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+});