Working on operations for Missing (data missing, by key) and Merge (concatenate arrays)

Author: jwadhams

logic.js

@@ -77,7 +77,12 @@ var jsonLogic = {},
 		"-" : function(a,b){ if(b === undefined){return -a;}else{return a - b;} },
 		"/" : function(a,b){ if(b === undefined){return a;}else{return a / b;} },
 		"min" : function(){ return Math.min.apply(this,arguments); },
-		"max" : function(){ return Math.max.apply(this,arguments); }
+		"max" : function(){ return Math.max.apply(this,arguments); },
+		"merge" : function(){
+			return Array.prototype.reduce.call(arguments, function(a,b){
+				return a.concat(b);
+			}, []);
+		}
 	};
 
 jsonLogic.is_logic = function(logic){
@@ -144,7 +149,7 @@ jsonLogic.apply = function(logic, data){
 	// Everyone else gets immediate depth-first recursion
 	values = values.map(function(val){ return jsonLogic.apply(val, data); });
 
-	// 'var' needs access to data, only available in this scope
+	// 'var' and 'missing' need access to data, only available in this scope
 	if(op === "var"){
 		var not_found = values[1] || null,
 			sub_props = String(values[0]).split(".");
@@ -154,6 +159,16 @@ jsonLogic.apply = function(logic, data){
 			if(data === undefined){ return not_found; } 
 		}
 		return data;
+
+	}else if(op === "missing"){
+		var missing = [];
+		values.map(function(data_key){ 
+			if(jsonLogic.apply({'var':data_key}, data) === null){
+				missing.push(data_key);
+			}
+		});
+		
+		return missing;
 	}
 
 	if(undefined === operations[op]){

tests/tests.json

@@ -60,6 +60,38 @@
 [{"if":[true, "apple", false, "banana", false, "carrot", "date"]}, null, "apple"],
 [{"if":[true, "apple", false, "banana", true, "carrot", "date"]}, null, "apple"],
 [{"if":[true, "apple", true, "banana", false, "carrot", "date"]}, null, "apple"],
-[{"if":[true, "apple", true, "banana", true, "carrot", "date"]}, null, "apple"]
+[{"if":[true, "apple", true, "banana", true, "carrot", "date"]}, null, "apple"],
 
+"Missing",
+
+[{"missing":[]}, null, []],
+[{"missing":["a"]}, null, ["a"]],
+[{"missing":"a"}, null, ["a"]],
+[{"missing":"a"}, {"a":"apple"}, []],
+[{"missing":["a"]}, {"a":"apple"}, []],
+[{"missing":["a","b"]}, {"a":"apple"}, ["b"]],
+[{"missing":["a","b"]}, {"b":"banana"}, ["a"]],
+[{"missing":["a","b"]}, {"a":"apple", "b":"banana"}, []],
+[{"missing":["a","b"]}, {}, ["a","b"]],
+[{"missing":["a","b"]}, null, ["a","b"]],
+
+[{"missing":["a.b"]}, null, ["a.b"]],
+[{"missing":["a.b"]}, {"a":"apple"}, ["a.b"]],
+[{"missing":["a.b"]}, {"a":{"c":"apple cake"}}, ["a.b"]],
+[{"missing":["a.b"]}, {"a":{"b":"apple brownie"}}, []],
+[{"missing":["a.b", "a.c"]}, {"a":{"b":"apple brownie"}}, ["a.c"]],
+
+"Missing and If are friends",
+[{"if":[ {"missing":"a"}, "missed it", "found it" ]}, {"a":"apple"}, "found it"],
+[{"if":[ {"missing":"a"}, "missed it", "found it" ]}, {"b":"banana"}, "missed it"],
+
+"Merge arrays",
+[{"merge":[]}, null, []],
+[{"merge":[["a"]]}, null, ["a"]],
+[{"merge":[["a"], ["b"]]}, null, ["a","b"]],
+[{"merge":[["a"], ["b"], ["c"]]}, null, ["a","b","c"]],
+[{"merge":[["a", "b"], ["c"]]}, null, ["a","b","c"]],
+[{"merge":[["a"], ["b", "c"]]}, null, ["a","b","c"]],
+
+"END"
 ]