1 files changed, 31 insertions, 0 deletions
diff --git a/node_modules/es-abstract/helpers/isPropertyDescriptor.js b/node_modules/es-abstract/helpers/isPropertyDescriptor.js
new file mode 100644
index 000000000..3eff7eb8f
--- /dev/null
+++ b/node_modules/es-abstract/helpers/isPropertyDescriptor.js
@@ -0,0 +1,31 @@
+'use strict';
+
+var GetIntrinsic = require('../GetIntrinsic');
+
+var has = require('has');
+var $TypeError = GetIntrinsic('%TypeError%');
+
+module.exports = function IsPropertyDescriptor(ES, Desc) {
+	if (ES.Type(Desc) !== 'Object') {
+		return false;
+	}
+	var allowed = {
+		'[[Configurable]]': true,
+		'[[Enumerable]]': true,
+		'[[Get]]': true,
+		'[[Set]]': true,
+		'[[Value]]': true,
+		'[[Writable]]': true
+	};
+
+	for (var key in Desc) { // eslint-disable-line no-restricted-syntax
+		if (has(Desc, key) && !allowed[key]) {
+			return false;
+		}
+	}
+
+	if (ES.IsDataDescriptor(Desc) && ES.IsAccessorDescriptor(Desc)) {
+		throw new $TypeError('Property Descriptors may not be both accessor and data descriptors');
+	}
+	return true;
+};