Bug 1113722 - Implement %TypedArray%.prototype.fill r=till

js/src/builtin/TypedArray.js

@@ -2,6 +2,45 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+// ES6 draft rev29 (2014/12/06) 22.2.3.8 %TypedArray%.prototype.fill(value [, start [, end ]])
+function TypedArrayFill(value, start = 0, end = undefined) {
+    // This function is not generic.
+    if (!IsObject(this) || !IsTypedArray(this)) {
+        return callFunction(CallTypedArrayMethodIfWrapped, this, value, start, end,
+                            "TypedArrayFill");
+    }
+
+    // Steps 1-2.
+    var O = this;
+
+    // Steps 3-5.
+    var len = TypedArrayLength(O);
+
+    // Steps 6-7.
+    var relativeStart = ToInteger(start);
+
+    // Step 8.
+    var k = relativeStart < 0
+            ? std_Math_max(len + relativeStart, 0)
+            : std_Math_min(relativeStart, len);
+
+    // Steps 9-10.
+    var relativeEnd = end === undefined ? len : ToInteger(end);
+
+    // Step 11.
+    var final = relativeEnd < 0
+                ? std_Math_max(len + relativeEnd, 0)
+                : std_Math_min(relativeEnd, len);
+
+    // Step 12.
+    for (; k < final; k++) {
+        O[k] = value;
+    }
+
+    // Step 13.
+    return O;
+}
+
 // ES6 draft rev28 (2014/10/14) 22.2.3.10 %TypedArray%.prototype.find(predicate[, thisArg]).
 function TypedArrayFind(predicate, thisArg = undefined) {
     // This function is not generic.

js/src/tests/ecma_6/TypedArray/fill.js

@@ -0,0 +1,77 @@
+const constructors = [
+    Int8Array,
+    Uint8Array,
+    Uint8ClampedArray,
+    Int16Array,
+    Uint16Array,
+    Int32Array,
+    Uint32Array,
+    Float32Array,
+    Float64Array
+];
+
+for (var constructor of constructors) {
+    assertDeepEq(constructor.prototype.fill.length, 1);
+
+    assertDeepEq(new constructor([]).fill(1), new constructor([]));
+    assertDeepEq(new constructor([1,1,1]).fill(2), new constructor([2,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 1), new constructor([1,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 1, 2), new constructor([1,2,1]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, -2), new constructor([1,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, -2, -1), new constructor([1,2,1]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, undefined), new constructor([2,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, undefined, undefined), new constructor([2,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 1, undefined), new constructor([1,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, undefined, 1), new constructor([2,1,1]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 2, 1), new constructor([1,1,1]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, -1, 1), new constructor([1,1,1]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, -2, 1), new constructor([1,1,1]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 1, -2), new constructor([1,1,1]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 0.1), new constructor([2,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 0.9), new constructor([2,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 1.1), new constructor([1,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 0.1, 0.9), new constructor([1,1,1]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 0.1, 1.9), new constructor([2,1,1]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 0.1, 1.9), new constructor([2,1,1]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, -0), new constructor([2,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 0, -0), new constructor([1,1,1]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, NaN), new constructor([2,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 0, NaN), new constructor([1,1,1]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, false), new constructor([2,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, true), new constructor([1,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, "0"), new constructor([2,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, "1"), new constructor([1,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, "-2"), new constructor([1,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, "-2", "-1"), new constructor([1,2,1]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, {valueOf: ()=>1}), new constructor([1,2,2]));
+    assertDeepEq(new constructor([1,1,1]).fill(2, 0, {valueOf: ()=>1}), new constructor([2,1,1]));
+
+    // Called from other globals.
+    if (typeof newGlobal === "function") {
+        var fill = newGlobal()[constructor.name].prototype.fill;
+        assertDeepEq(fill.call(new constructor([3, 2, 1]), 2), new constructor([2, 2, 2]));
+    }
+
+    // Throws if `this` isn't a TypedArray.
+    var nonTypedArrays = [undefined, null, 1, false, "", Symbol(), [], {}, /./,
+                         /* new Proxy(new constructor(), {}) // This probably should throw */
+                         ];
+    nonTypedArrays.forEach(nonTypedArray => {
+        assertThrowsInstanceOf(function() {
+            constructor.prototype.fill.call(nonTypedArray, 1);
+        }, TypeError);
+    });
+
+    // Test that the length getter is never called.
+    Object.defineProperty(new constructor([1, 2, 3]), "length", {
+        get() {
+            throw new Error("length accessor called");
+        }
+    }).fill(1);
+}
+
+assertDeepEq(new Float32Array([0, 0]).fill(NaN), new Float32Array([NaN, NaN]));
+assertDeepEq(new Float64Array([0, 0]).fill(NaN), new Float64Array([NaN, NaN]));
+
+if (typeof reportCompare === "function")
+    reportCompare(true, true);

js/src/vm/TypedArrayObject.cpp

@@ -781,6 +781,7 @@ TypedArrayObject::protoFunctions[] = {
     JS_FN("subarray", TypedArrayObject::subarray, 2, 0),
     JS_FN("set", TypedArrayObject::set, 2, 0),
     JS_FN("copyWithin", TypedArrayObject::copyWithin, 2, 0),
+    JS_SELF_HOSTED_FN("fill", "TypedArrayFill", 3, 0),
     JS_SELF_HOSTED_FN("find", "TypedArrayFind", 2, 0),
     JS_SELF_HOSTED_FN("findIndex", "TypedArrayFindIndex", 2, 0),
     JS_SELF_HOSTED_FN("indexOf", "TypedArrayIndexOf", 2, 0),