1 files changed, 63 insertions, 0 deletions
diff --git a/js/src/tests/non262/Set/is-superset-of.js b/js/src/tests/non262/Set/is-superset-of.js
new file mode 100644
index 0000000000..d814f061f9
--- /dev/null
+++ b/js/src/tests/non262/Set/is-superset-of.js
@@ -0,0 +1,63 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * https://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+if (typeof getBuildConfiguration === "undefined") {
+    var getBuildConfiguration = SpecialPowers.Cu.getJSTestingFunctions().getBuildConfiguration;
+}
+
+if (typeof getRealmConfiguration === "undefined") {
+    var getRealmConfiguration = SpecialPowers.Cu.getJSTestingFunctions().getRealmConfiguration;
+}
+
+if (getBuildConfiguration()['new-set-methods'] && getRealmConfiguration().enableNewSetMethods) {
+
+    assertEq(typeof Set.prototype.isSupersetOf, 'function');
+    assertEq(Set.prototype.isSupersetOf.length, 1);
+    assertEq(Set.prototype.isSupersetOf.name, 'isSupersetOf');
+
+    assertEq(new Set([1, true, null]).isSupersetOf(new Set()), true);
+    assertEq(new Set([1, true, null]).isSupersetOf([1, true, null]), true);
+    assertEq(new Set([1, 2, 3]).isSupersetOf([2, 3, 4]), false);
+    assertEq(new Set([1, 2, 3]).isSupersetOf([3]), true);
+    // Works when the argument is a custom iterable which follows the Symbol.iterator protocol
+    assertEq(new Set([1, 2, 3]).isSupersetOf(makeArrayIteratorWithHasMethod([2, 3])), true);
+    assertEq(new Set(['a']).isSupersetOf('abc'), false);
+
+    // Works when the `this` is a custom iterable which follows the Symbol.iterator protocol
+    assertEq(Set.prototype.isSupersetOf.call(makeArrayIteratorWithHasMethod([1, 2, 3, 3, 2]), [4, 5, 6]), false);
+
+    // Does not modify the original set object
+    const set = new Set([1]);
+    assertEq(set.isSupersetOf([2]) !== set, true);
+
+    // Argument must be iterable
+    assertThrowsInstanceOf(function () {
+        const set = new Set();
+        set.isSupersetOf();
+    }, TypeError);
+    for (const arg of [null, {}, true, 1, undefined, NaN, Symbol()]) {
+        assertThrowsInstanceOf(function () {
+            const set = new Set();
+            set.isSupersetOf(arg);
+        }, TypeError);
+    }
+
+    // `this` must be an Object
+    for (const arg of [null, undefined, Symbol()]) {
+        assertThrowsInstanceOf(function () {
+            Set.prototype.isSupersetOf.call(arg, []);
+        }, TypeError);
+    }
+
+    // `this` must be iterable
+    assertThrowsInstanceOf(function () {
+        Set.prototype.isSupersetOf.call({}, []);
+    }, TypeError);
+} else {
+    assertEq(typeof Set.prototype.isSupersetOf, 'undefined');
+}
+
+if (typeof reportCompare === "function")
+    reportCompare(true, true);