Function shouldUseNative

dash/deps/react@16.14.0.js:74–116

()

  }

  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;
  	}
  }

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