#2 Support for nulls

Author: pkafel

json-diff.js

@@ -7,6 +7,7 @@ REMOVE = "REMOVE";
 
 // TYPES
 ARRAY = "ARRAY";
+NULL = "NULL";
 OBJECT = "OBJECT";
 SCALAR = "SCALAR";
 
@@ -32,6 +33,7 @@ function ValidationException(leftError, rightError) {
 function getDiffRepresentation(left, right) {
 
   function _getType(v) {
+    if(v === null) return NULL;
     var type = typeof(v);
     if (type === 'number' || type === 'string' || type === 'boolean') return SCALAR;
     if (type === 'object') {
@@ -102,8 +104,10 @@ function getDiffRepresentation(left, right) {
           result = result.concat(_getScalarsDiff(null, left[i], null,  right[i]));
         } else if(leftType === OBJECT) {
           result.push(new Diff(null, _getJsonsDiff(left[i], right[i]), NONE, OBJECT));
-        } else {
+        } else if(leftType === ARRAY){
           result.push(new Diff(null, _getArraysDiff(left[i], right[i]), NONE, ARRAY));
+        } else {
+          result.push(new Diff(null, null, NONE, NULL));
         }
       } else {
         result.push(new Diff(null, _getInDepthDiff(left[i], ADD), ADD, leftType));
@@ -134,8 +138,10 @@ function getDiffRepresentation(left, right) {
             result = result.concat(_getScalarsDiff(key, left[key], key,  right[key]));
           } else if (leftType === OBJECT) {
             result.push(new Diff(key, _getJsonsDiff(left[key], right[key]), NONE, OBJECT));
-          } else {
+          } else if(leftType == ARRAY){
             result.push(new Diff(key, _getArraysDiff(left[key], right[key]), NONE, ARRAY));
+          } else {
+            result.push(new Diff(key, null, NONE, NULL));
           }
         } else {
           result.push(new Diff(key, _getInDepthDiff(left[key], ADD), ADD, leftType));

test/spec/json-diff-spec.js

@@ -222,4 +222,28 @@ describe("Get Json diff representation", function() {
     };
     expect(call).toThrow(new ValidationException("Input is not a valid JSON", null));
   });
+
+  it("Diff should throw exception with correct error message when one of jsons is null", function() {
+    var call = function() {
+      getDiffRepresentation("{}", "null");
+    };
+    expect(call).toThrow(new ValidationException(null, "Input is not a valid JSON"));
+  });
+
+  it("Diff should handle null values", function() {
+    var result = getDiffRepresentation("{\"a\":null,\"b\":[null]}", "{\"b\":[null],\"a\":null}");
+
+    expect(result.topType).toEqual(OBJECT);
+    expect(result.diff[0].key).toEqual("a");
+    expect(result.diff[0].op).toEqual(NONE);
+    expect(result.diff[0].valueType).toEqual(NULL);
+    expect(result.diff[0].value).toEqual(null);
+    expect(result.diff[1].key).toEqual("b");
+    expect(result.diff[1].op).toEqual(NONE);
+    expect(result.diff[1].valueType).toEqual(ARRAY);
+    expect(result.diff[1].value[0].key).toEqual(null);
+    expect(result.diff[1].value[0].value).toEqual(null);
+    expect(result.diff[1].value[0].valueType).toEqual(NULL);
+    expect(result.diff[1].value[0].op).toEqual(NONE);
+  });
 });