Merge pull request #43 from joeldenning/issue35

Fix for issue #35 -- apply diffs for arrays

Author: Phillip Clark

index.js

@@ -249,7 +249,7 @@
     if (target && source && change && change.kind) {
       var it = target,
         i = -1,
-        last = change.path.length - 1;
+        last = change.path ? change.path.length - 1 : 0;
       while (++i < last) {
         if (typeof it[change.path[i]] === 'undefined') {
           it[change.path[i]] = (typeof change.path[i] === 'number') ? [] : {};
@@ -258,7 +258,7 @@
       }
       switch (change.kind) {
         case 'A':
-          applyArrayChange(it[change.path[i]], change.index, change.item);
+          applyArrayChange(change.path ? it[change.path[i]] : it, change.index, change.item);
           break;
         case 'D':
           delete it[change.path[i]];

test/tests.js

@@ -482,4 +482,22 @@ describe('deep-diff', function() {
 
     });
 
+    describe('regression test for bug #35', function() {
+        var lhs = ["a", "a", "a"];
+        var rhs = ["a"];
+
+        it('can apply diffs between two top level arrays', function() {
+            var differences = deep.diff(lhs, rhs);
+
+            /* We must apply the differences in reverse order, since the array indices 
+               in the diff become stale/invalid if you delete elements from the array
+               whose indices are in ascending order */
+            for (var i = differences.length - 1; i >= 0; i--) {
+                deep.applyChange(lhs, true, differences[i]);
+            }
+
+            expect(lhs).to.eql(["a"]);
+        });
+    });
+
 });