1 files changed, 74 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Array/fromAsync/this-constructor-operations.js b/js/src/tests/test262/built-ins/Array/fromAsync/this-constructor-operations.js
new file mode 100644
index 0000000000..ee96890677
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Array/fromAsync/this-constructor-operations.js
@@ -0,0 +1,74 @@
+// |reftest| async
+// Copyright (C) 2023 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.fromasync
+description: >
+  Order of user-observable operations on a custom this-value and its instances
+includes: [compareArray.js, asyncHelpers.js]
+flags: [async]
+features: [Array.fromAsync]
+---*/
+
+function formatPropertyName(propertyKey, objectName = "") {
+  switch (typeof propertyKey) {
+    case "symbol":
+      if (Symbol.keyFor(propertyKey) !== undefined) {
+        return `${objectName}[Symbol.for('${Symbol.keyFor(propertyKey)}')]`;
+      } else if (propertyKey.description.startsWith('Symbol.')) {
+        return `${objectName}[${propertyKey.description}]`;
+      } else {
+        return `${objectName}[Symbol('${propertyKey.description}')]`
+      }
+    case "string":
+      if (propertyKey !== String(Number(propertyKey)))
+        return objectName ? `${objectName}.${propertyKey}` : propertyKey;
+      // fall through
+    default:
+      // integer or string integer-index
+      return `${objectName}[${propertyKey}]`;
+  }
+}
+
+asyncTest(async function () {
+  const expectedCalls = [
+    "construct MyArray",
+    "defineProperty A[0]",
+    "defineProperty A[1]",
+    "set A.length"
+  ];
+  const actualCalls = [];
+
+  function MyArray(...args) {
+    actualCalls.push("construct MyArray");
+    return new Proxy(Object.create(null), {
+      set(target, key, value) {
+        actualCalls.push(`set ${formatPropertyName(key, "A")}`);
+        return Reflect.set(target, key, value);
+      },
+      defineProperty(target, key, descriptor) {
+        actualCalls.push(`defineProperty ${formatPropertyName(key, "A")}`);
+        return Reflect.defineProperty(target, key, descriptor);
+      }
+    });
+  }
+
+  let result = await Array.fromAsync.call(MyArray, [1, 2]);
+  assert.compareArray(expectedCalls, actualCalls, "order of operations for array argument");
+
+  actualCalls.splice(0);  // reset
+
+  const expectedCallsForArrayLike = [
+    "construct MyArray",
+    "defineProperty A[0]",
+    "defineProperty A[1]",
+    "set A.length"
+  ];
+  result = await Array.fromAsync.call(MyArray, {
+    length: 2,
+    0: 1,
+    1: 2
+  });
+  assert.compareArray(expectedCallsForArrayLike, actualCalls, "order of operations for array-like argument");
+});