1 files changed, 76 insertions, 0 deletions
diff --git a/js/src/tests/non262/TypedArray/from_errors.js b/js/src/tests/non262/TypedArray/from_errors.js
new file mode 100644
index 0000000000..281b1b5129
--- /dev/null
+++ b/js/src/tests/non262/TypedArray/from_errors.js
@@ -0,0 +1,76 @@
+for (var constructor of anyTypedArrayConstructors) {
+    // %TypedArray%.from throws if the argument is undefined or null.
+    assertThrowsInstanceOf(() => constructor.from(), TypeError);
+    assertThrowsInstanceOf(() => constructor.from(undefined), TypeError);
+    assertThrowsInstanceOf(() => constructor.from(null), TypeError);
+
+    // Unlike Array.from, %TypedArray%.from doesn't get or set the length property.
+    function ObjectWithThrowingLengthGetterSetter(...rest) {
+        var ta = new constructor(...rest);
+        Object.defineProperty(ta, "length", {
+            configurable: true,
+            get() { throw new RangeError("getter!"); },
+            set() { throw new RangeError("setter!"); }
+        });
+        return ta;
+    }
+    ObjectWithThrowingLengthGetterSetter.from = constructor.from;
+    assertEq(ObjectWithThrowingLengthGetterSetter.from([123])[0], 123);
+
+    // %TypedArray%.from throws if mapfn is neither callable nor undefined.
+    assertThrowsInstanceOf(() => constructor.from([3, 4, 5], {}), TypeError);
+    assertThrowsInstanceOf(() => constructor.from([3, 4, 5], "also not a function"), TypeError);
+    assertThrowsInstanceOf(() => constructor.from([3, 4, 5], null), TypeError);
+
+    // Even if the function would not have been called.
+    assertThrowsInstanceOf(() => constructor.from([], JSON), TypeError);
+
+    // If mapfn is not undefined and not callable, the error happens before anything else.
+    // Before calling the constructor, before touching the arrayLike.
+    var log = "";
+    var obj;
+    function C(...rest) {
+        log += "C";
+        obj = new constructor(...rest);
+        return obj;
+    }
+    var p = new Proxy({}, {
+        has: function () { log += "1"; },
+        get: function () { log += "2"; },
+        getOwnPropertyDescriptor: function () { log += "3"; }
+    });
+    assertThrowsInstanceOf(() => constructor.from.call(C, p, {}), TypeError);
+    assertEq(log, "");
+
+    // If mapfn throws, the new object has already been created.
+    var arrayish = {
+        get length() { log += "l"; return 1; },
+        get 0() { log += "0"; return "q"; }
+    };
+    log = "";
+    var exc = {surprise: "ponies"};
+    assertThrowsValue(() => constructor.from.call(C, arrayish, () => { throw exc; }), exc);
+    assertEq(log, "lC0");
+    assertEq(obj instanceof constructor, true);
+
+    // It's a TypeError if the @@iterator property is a primitive (except null and undefined).
+    for (var primitive of ["foo", 17, Symbol(), true]) {
+        assertThrowsInstanceOf(() => constructor.from({[Symbol.iterator] : primitive}), TypeError);
+    }
+    assertDeepEq(constructor.from({[Symbol.iterator]: null}), new constructor());
+    assertDeepEq(constructor.from({[Symbol.iterator]: undefined}), new constructor());
+
+    // It's a TypeError if the iterator's .next() method returns a primitive.
+    for (var primitive of [undefined, null, "foo", 17, Symbol(), true]) {
+        assertThrowsInstanceOf(
+            () => constructor.from({
+                [Symbol.iterator]() {
+                    return {next() { return primitive; }};
+                }
+            }),
+        TypeError);
+    }
+}
+
+if (typeof reportCompare === "function")
+    reportCompare(true, true);