closes #11. Added prefilter capability

Author: Phillip Clark

index.js

@@ -74,10 +74,13 @@
   	return arr;
   }
 
-  function deepDiff(lhs, rhs, changes, path, key, stack) {
+  function deepDiff(lhs, rhs, changes, prefilter, path, key, stack) {
   	path = path || [];
   	var currentPath = path.slice(0);
-  	if (key) { currentPath.push(key); }
+  	if (key) {
+  		if (prefilter && prefilter(currentPath, key)) return;
+  		currentPath.push(key);
+  	}
   	var ltype = typeof lhs;
   	var rtype = typeof rhs;
   	if (ltype === 'undefined') {
@@ -104,7 +107,7 @@
   					if (i >= rhs.length) {
   						changes(new DiffArray(currentPath, i, new DiffDeleted(undefined, lhs[i])));
   					} else {
-  						deepDiff(lhs[i], rhs[i], ea, [], null, stack);
+  						deepDiff(lhs[i], rhs[i], ea, prefilter, [], null, stack);
   					}
   				}
   				while(i < rhs.length) {
@@ -116,14 +119,14 @@
   				akeys.forEach(function(k) {
   					var i = pkeys.indexOf(k);
   					if (i >= 0) {
-  						deepDiff(lhs[k], rhs[k], changes, currentPath, k, stack);
+  						deepDiff(lhs[k], rhs[k], changes, prefilter, currentPath, k, stack);
   						pkeys = arrayRemove(pkeys, i);
   					} else {
-  						deepDiff(lhs[k], undefined, changes, currentPath, k, stack);
+  						deepDiff(lhs[k], undefined, changes, prefilter, currentPath, k, stack);
   					}
   				});
   				pkeys.forEach(function(k) {
-  					deepDiff(undefined, rhs[k], changes, currentPath, k, stack);
+  					deepDiff(undefined, rhs[k], changes, prefilter, currentPath, k, stack);
   				});
   			}
   			stack.length = stack.length - 1;
@@ -135,13 +138,15 @@
   	}
   }
 
-  function accumulateDiff(lhs, rhs, accum) {
+  function accumulateDiff(lhs, rhs, prefilter, accum) {
   	accum = accum || [];
-  	deepDiff(lhs, rhs, function(diff) {
-  		if (diff) {
-  			accum.push(diff);
-  		}
-  	});
+  	deepDiff(lhs, rhs,
+  		function(diff) {
+  			if (diff) {
+  				accum.push(diff);
+  			}
+  		},
+  		prefilter);
   	return (accum.length) ? accum : undefined;
   }
 

test/tests.html

@@ -17,8 +17,8 @@
     DeepDiff = { Conflict: "here" };
     DeepDiffConflict = DeepDiff;
   </script>
-  <script src="../releases/deep-diff-0.1.5.min.js"></script>
-  <!--script src="../index.js"></script-->
+  <!--<script src="../releases/deep-diff-0.1.5.min.js"></script>-->
+  <script src="../index.js"></script>
   <script>mocha.setup('bdd')</script>
   <script src="tests.js"></script>
 

test/tests.js

@@ -161,6 +161,56 @@ describe('deep-diff', function() {
 
 	});
 
+
+
+	describe('When filtering keys', function() {
+		var lhs = { enhancement: 'Filter/Ignore Keys?', numero: 11, submitted_by: 'ericclemmons', supported_by: ['ericclemmons'], status: 'open' };
+		var rhs = { enhancement: 'Filter/Ignore Keys?', numero: 11, submitted_by: 'ericclemmons', supported_by: [
+			'ericclemmons',
+			'TylerGarlick',
+			'flitbit',
+			'ergdev'
+		], status: 'closed', fixed_by: 'flitbit' };
+
+		describe('if the filtered property is an array', function() {
+
+			it('changes to the array do not appear as a difference', function() {
+				var prefilter = function(path, key) {
+					return key === 'supported_by'
+				};
+				var diff = deep(lhs, rhs, prefilter);
+				expect(diff).to.be.ok();
+				expect(diff.length).to.be(2);
+				expect(diff[0]).to.have.property('kind');
+				expect(diff[0].kind).to.be('E');
+				expect(diff[1]).to.have.property('kind');
+				expect(diff[1].kind).to.be('N');
+			});
+
+		});
+
+		describe('if the filtered property is not an array', function() {
+
+			it('changes do not appear as a difference', function() {
+				var prefilter = function(path, key) {
+					return key === 'fixed_by'
+				};
+				var diff = deep(lhs, rhs, prefilter);
+				expect(diff).to.be.ok();
+				expect(diff.length).to.be(4);
+				expect(diff[0]).to.have.property('kind');
+				expect(diff[0].kind).to.be('A');
+				expect(diff[1]).to.have.property('kind');
+				expect(diff[1].kind).to.be('A');
+				expect(diff[2]).to.have.property('kind');
+				expect(diff[2].kind).to.be('A');
+				expect(diff[3]).to.have.property('kind');
+				expect(diff[3].kind).to.be('E');
+			});
+
+		});
+	});
+
 	describe('A target that has nested values', function() {
 		var nestedOne = { noChange: 'same', levelOne: { levelTwo: 'value' } };
 		var nestedTwo = { noChange: 'same', levelOne: { levelTwo: 'another value' } };