1 files changed, 48 insertions, 0 deletions
diff --git a/node_modules/es-abstract/helpers/assertRecord.js b/node_modules/es-abstract/helpers/assertRecord.js
new file mode 100644
index 000000000..45e115a44
--- /dev/null
+++ b/node_modules/es-abstract/helpers/assertRecord.js
@@ -0,0 +1,48 @@
+'use strict';
+
+var GetIntrinsic = require('../GetIntrinsic');
+
+var $TypeError = GetIntrinsic('%TypeError%');
+var $SyntaxError = GetIntrinsic('%SyntaxError%');
+
+var has = require('has');
+
+var predicates = {
+	// https://ecma-international.org/ecma-262/6.0/#sec-property-descriptor-specification-type
+	'Property Descriptor': function isPropertyDescriptor(Type, Desc) {
+		if (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
+			if (has(Desc, key) && !allowed[key]) {
+				return false;
+			}
+		}
+
+		var isData = has(Desc, '[[Value]]');
+		var IsAccessor = has(Desc, '[[Get]]') || has(Desc, '[[Set]]');
+		if (isData && IsAccessor) {
+			throw new $TypeError('Property Descriptors may not be both accessor and data descriptors');
+		}
+		return true;
+	}
+};
+
+module.exports = function assertRecord(Type, recordType, argumentName, value) {
+	var predicate = predicates[recordType];
+	if (typeof predicate !== 'function') {
+		throw new $SyntaxError('unknown record type: ' + recordType);
+	}
+	if (!predicate(Type, value)) {
+		throw new $TypeError(argumentName + ' must be a ' + recordType);
+	}
+};