EAGLESIX-2717: basic port

lib/pipeline/expressions/SetUnionExpression.js

@@ -8,6 +8,7 @@
  * @module mungedb-aggregate
  * @constructor
  **/
+
 var SetUnionExpression = module.exports = function SetUnionExpression() {
 	this.nargs = 2;
 	base.call(this);
@@ -29,24 +30,28 @@ proto.getOpName = function getOpName() {
 };
 
 /**
- * Takes 2 objects. Unions the objects
+ * Takes 2 objects. Returns the union of the two objects.
  * @method evaluateInternal
  **/
 proto.evaluateInternal = function evaluateInternal(vars) {
+
+	var unionSet = {};
+
 	var object1 = this.operands[0].evaluateInternal(vars),
 		object2 = this.operands[1].evaluateInternal(vars);
-	if (object1 instanceof Array) throw new Error(this.getOpName() + ": object 1 must be an object");
-	if (object2 instanceof Array) throw new Error(this.getOpName() + ": object 2 must be an object");
 
-	var object3 = {};
+	//Deviation from Mongo. We are using objects for this, while they use arrays. 
+	if (typeof object1 != object) throw new Error("All operands of " + this.getOpName() + "must be objects. First argument is of type: " + typeof object1);
+	if (typeof object2 != object) throw new Error("All operands of " + this.getOpName() + "must be objects. Second argument is of type: " + typeof object2);
+
 	for (var attrname1 in object1) {
-		object3[attrname1] = object1[attrname1];
+		unionSet[attrname1] = object1[attrname1];
 	}
 	for (var attrname2 in object2) {
-		object3[attrname2] = object2[attrname2];
+		unionSet[attrname2] = object2[attrname2];
 	}
 
-	return object3;
+	return unionSet;
 };
 
 /** Register Expression */