1 files changed, 182 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Set/prototype/isSupersetOf/set-like-class-order.js b/js/src/tests/test262/built-ins/Set/prototype/isSupersetOf/set-like-class-order.js
new file mode 100644
index 0000000000..e688569c7b
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+++ b/js/src/tests/test262/built-ins/Set/prototype/isSupersetOf/set-like-class-order.js
@@ -0,0 +1,182 @@
+// |reftest| skip -- set-methods is not supported
+// Copyright (C) 2023 Anthony Frehner and Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-set.prototype.issupersetof
+description: Set.prototype.isSupersetOf calls a Set-like class's methods in order
+features: [set-methods]
+includes: [compareArray.js]
+---*/
+
+let observedOrder = [];
+
+function observableIterator() {
+  let values = ["a", "b", "c"];
+  let index = 0;
+  return {
+    get next() {
+      observedOrder.push("getting next");
+      return function () {
+        observedOrder.push("calling next");
+        return {
+          get done() {
+            observedOrder.push("getting done");
+            return index >= values.length;
+          },
+          get value() {
+            observedOrder.push("getting value");
+            return values[index++];
+          },
+        };
+      };
+    },
+  };
+}
+
+class MySetLike {
+  get size() {
+    observedOrder.push("getting size");
+    return {
+      valueOf: function () {
+        observedOrder.push("ToNumber(size)");
+        return 3;
+      },
+    };
+  }
+  get has() {
+    observedOrder.push("getting has");
+    return function (v) {
+      throw new Test262Error("Set.prototype.isSupersetOf should not call its argument's has method");
+    };
+  }
+  get keys() {
+    observedOrder.push("getting keys");
+    return function () {
+      observedOrder.push("calling keys");
+      return observableIterator();
+    };
+  }
+}
+
+// this is smaller than argument
+{
+  observedOrder = [];
+
+  const s1 = new Set(["a", "b"]);
+  const s2 = new MySetLike();
+  const result = s1.isSupersetOf(s2);
+
+  const expectedOrder = [
+    "getting size",
+    "ToNumber(size)",
+    "getting has",
+    "getting keys",
+    // no iteration
+  ];
+
+  assert.sameValue(result, false);
+  assert.compareArray(observedOrder, expectedOrder);
+}
+
+// this is same size as argument - stops eagerly
+{
+  observedOrder = [];
+
+  const s1 = new Set(["a", "x", "c"]);
+  const s2 = new MySetLike();
+  const result = s1.isSupersetOf(s2);
+
+  const expectedOrder = [
+    "getting size",
+    "ToNumber(size)",
+    "getting has",
+    "getting keys",
+    "calling keys",
+    "getting next",
+    // first iteration, has value
+    "calling next",
+    "getting done",
+    "getting value",
+    // second iteration, has value
+    "calling next",
+    "getting done",
+    "getting value",
+  ];
+
+  assert.sameValue(result, false);
+  assert.compareArray(observedOrder, expectedOrder);
+}
+
+// this is same size as argument - full run
+{
+  observedOrder = [];
+
+  const s1 = new Set(["a", "b", "c"]);
+  const s2 = new MySetLike();
+  const result = s1.isSupersetOf(s2);
+
+  const expectedOrder = [
+    "getting size",
+    "ToNumber(size)",
+    "getting has",
+    "getting keys",
+    "calling keys",
+    "getting next",
+    // first iteration, has value
+    "calling next",
+    "getting done",
+    "getting value",
+    // second iteration, has value
+    "calling next",
+    "getting done",
+    "getting value",
+    // third iteration, has value
+    "calling next",
+    "getting done",
+    "getting value",
+    // fourth iteration, no value; ends
+    "calling next",
+    "getting done",
+  ];
+
+  assert.sameValue(result, true);
+  assert.compareArray(observedOrder, expectedOrder);
+}
+
+// this is larger than argument
+{
+  observedOrder = [];
+
+  const s1 = new Set(["a", "b", "c", "d"]);
+  const s2 = new MySetLike();
+  const result = s1.isSupersetOf(s2);
+
+  const expectedOrder = [
+    "getting size",
+    "ToNumber(size)",
+    "getting has",
+    "getting keys",
+    "calling keys",
+    "getting next",
+    // first iteration, has value
+    "calling next",
+    "getting done",
+    "getting value",
+    // second iteration, has value
+    "calling next",
+    "getting done",
+    "getting value",
+    // third iteration, has value
+    "calling next",
+    "getting done",
+    "getting value",
+    // fourth iteration, no value; ends
+    "calling next",
+    "getting done",
+  ];
+
+  assert.sameValue(result, true);
+  assert.compareArray(observedOrder, expectedOrder);
+}
+
+reportCompare(0, 0);