Function shouldUseNative

code/composition/public/app.js:825–867

()

}

function shouldUseNative() {
	try {
		if (!Object.assign) {
			return false;
		}

		// Detect buggy property enumeration order in older V8 versions.

		// https://bugs.chromium.org/p/v8/issues/detail?id=4118
		var test1 = new String('abc');  // eslint-disable-line no-new-wrappers
		test1[5] = 'de';
		if (Object.getOwnPropertyNames(test1)[0] === '5') {
			return false;
		}

		// https://bugs.chromium.org/p/v8/issues/detail?id=3056
		var test2 = {};
		for (var i = 0; i < 10; i++) {
			test2['_' + String.fromCharCode(i)] = i;
		}
		var order2 = Object.getOwnPropertyNames(test2).map(function (n) {
			return test2[n];
		});
		if (order2.join('') !== '0123456789') {
			return false;
		}

		// https://bugs.chromium.org/p/v8/issues/detail?id=3056
		var test3 = {};
		'abcdefghijklmnopqrst'.split('').forEach(function (letter) {
			test3[letter] = letter;
		});
		if (Object.keys(Object.assign({}, test3)).join('') !==
				'abcdefghijklmnopqrst') {
			return false;
		}

		return true;
	} catch (err) {
		// We don't expect any of the above to throw, but better to be safe.
		return false;
	}
}

module.exports = shouldUseNative() ? Object.assign : function (target, source) {
	var from;