JavaScriptCore-7601.1.46.3.tar.gz

[apple/javascriptcore.git] / tests / stress / array-from-set-length.js

diff --git a/tests/stress/array-from-set-length.js b/tests/stress/array-from-set-length.js
new file mode 100644 (file)
index 0000000..ab6adea
--- /dev/null
+++ b/tests/stress/array-from-set-length.js
@@ -0,0 +1,45 @@
+function shouldBe(actual, expected) {
+    if (actual !== expected)
+        throw new Error('bad value: ' + actual);
+}
+
+for (var i = 0; i < 10; ++i) {
+    Object.defineProperty(Array.prototype, i, {
+        get() {
+            throw new Error('get is called.');
+        },
+        set(value) {
+            throw new Error('set is called.');
+        }
+    });
+}
+
+class ArrayLike {
+    constructor(length) {
+        this.lengthCalled = false;
+        this._length = length;
+    }
+    set length(value) {
+        this.lengthCalled = true;
+        this._length = value;
+    }
+    get length() {
+        return this._length;
+    }
+}
+
+var arrayLike = new ArrayLike(10);
+for (var i = 0; i < 10; ++i) {
+    arrayLike[i] = i;
+}
+shouldBe(arrayLike.lengthCalled, false);
+
+var generated = Array.from.call(ArrayLike, arrayLike);
+
+shouldBe(generated.length, 10);
+shouldBe(generated instanceof ArrayLike, true);
+for (var i = 0; i < 10; ++i) {
+    shouldBe(generated[i], i);
+}
+shouldBe(arrayLike.lengthCalled, false);
+shouldBe(generated.lengthCalled, true);