Adds update task to ArrayBuffer to fix incomplete browser implement…

…ations

polyfills/ArrayBuffer/config.toml

@@ -35,3 +35,4 @@ samsung_mob = "<2"
 [install]
 module = "js-polyfills"
 paths = [ "typedarray.js" ]
+postinstall = "update.task.js"

polyfills/ArrayBuffer/detect.js

@@ -0,0 +1,3 @@
+// use "Int8Array" as a proxy for support of "TypedArray" subclasses
+// confirm that the prototype of "Int8Array" is NOT the "Object" prototype, which is a bug in IE11 and maybe other old browsers
+'ArrayBuffer' in self && 'DataView' in self && 'Int8Array' in self && Object.getPrototypeOf(self.Int8Array) !== Object.getPrototypeOf(Object)

polyfills/ArrayBuffer/tests.js

@@ -0,0 +1,52 @@
+/* eslint-env mocha, browser */
+/* global proclaim, ArrayBuffer, DataView, Int8Array */
+
+describe('ArrayBuffer', function () {
+	it('should expose a property named ArrayBuffer on the global object', function() {
+		proclaim.isTrue('ArrayBuffer' in window);
+	});
+
+	it('should be a function', function() {
+		proclaim.isFunction(ArrayBuffer);
+	});
+
+	it('should throw an error if called without `new` operator', function () {
+		proclaim.throws(function () {
+			ArrayBuffer();
+		}, TypeError);
+	});
+});
+
+describe('DataView', function () {
+	it('should expose a property named DataView on the global object', function() {
+		proclaim.isTrue('ArrayBuffer' in window);
+	});
+
+	it('should be a function', function() {
+		proclaim.isFunction(DataView);
+	});
+
+	it('should throw an error if called without `new` operator', function () {
+		proclaim.throws(function () {
+			DataView();
+		}, TypeError);
+	});
+});
+
+// use "Int8Array" as a proxy for all "TypedArray" subclasses
+
+describe('Int8Array', function () {
+	it('should expose a property named Int8Array on the global object', function() {
+		proclaim.isTrue('Int8Array' in window);
+	});
+
+	it('should be a function', function() {
+		proclaim.isFunction(Int8Array);
+	});
+
+	it('should throw an error if called without `new` operator', function () {
+		proclaim.throws(function () {
+			Int8Array();
+		}, TypeError);
+	});
+});

polyfills/ArrayBuffer/update.task.js

@@ -0,0 +1,53 @@
+/* eslint-env node */
+
+'use strict';
+
+var fs = require('graceful-fs');
+var path = require('path');
+var arrayBufferPolyfillOutput = path.resolve('polyfills/ArrayBuffer/polyfill.js');
+
+var polyfill = fs.readFileSync(arrayBufferPolyfillOutput, 'utf-8');
+
+// always attach these to `self`, since the existing browser implementation may be incomplete (e.g. IE11)
+[
+	'ArrayBuffer',
+	'Int8Array',
+	'Uint8Array',
+	'Uint8ClampedArray',
+	'Int16Array',
+	'Uint16Array',
+	'Int32Array',
+	'Uint32Array',
+	'Float32Array',
+	'Float64Array',
+	'DataView'
+].forEach(function (kind) {
+	polyfill = polyfill.replace(
+		'global.' + kind + ' = global.' + kind + ' || ' + kind + ';',
+		'global.' + kind + ' = ' + kind + ';'
+	)
+});
+
+// add helper function for defining properties correctly (all properties should be `writable` and `configurable`)
+polyfill = polyfill.replace(
+	/(function packF32\(v\).+?\n)/,
+	'$1\n' +
+	'  function ObjectDefinePropertyConfigurable(o, prop, desc) {\n' +
+	'    desc.writable = true;\n' +
+	'    desc.configurable = true;\n' +
+	'    return Object.defineProperty(o, prop, desc);\n' +
+	'  }\n'
+);
+
+// replace usage of `Object.defineProperty` with helper function
+[
+	'$TypedArray$',
+	'this',
+	'DataView'
+].forEach(function (kind) {
+	polyfill = polyfill
+		.split('Object.defineProperty(' + kind)
+		.join('ObjectDefinePropertyConfigurable(' + kind)
+});
+
+fs.writeFileSync(arrayBufferPolyfillOutput, polyfill, 'utf-8');