iD.actions.Revert (see #537)

index.html

@@ -169,6 +169,7 @@
         <script src='js/id/actions/rotate_way.js'></script>
         <script src='js/id/actions/restrict_turn.js'></script>
         <script src='js/id/actions/reverse.js'></script>
+        <script src='js/id/actions/revert.js'></script>
         <script src='js/id/actions/straighten.js'></script>
         <script src='js/id/actions/split.js'></script>
         <script src='js/id/actions/unrestrict_turn.js'></script>

js/id/actions/revert.js

@@ -0,0 +1,5 @@
+iD.actions.Revert = function(entity) {
+    return function(graph) {
+        return graph.revert(entity);
+    };
+};

test/index.html

@@ -147,6 +147,7 @@
     <script src='../js/id/actions/orthogonalize.js'></script>
     <script src='../js/id/actions/restrict_turn.js'></script>
     <script src='../js/id/actions/reverse.js'></script>
+    <script src='../js/id/actions/revert.js'></script>
     <script src='../js/id/actions/rotate_way.js'></script>
     <script src='../js/id/actions/split.js'></script>
     <script src='../js/id/actions/straighten.js'></script>
@@ -250,6 +251,7 @@
     <script src="spec/actions/noop.js"></script>
     <script src="spec/actions/restrict_turn.js"></script>
     <script src="spec/actions/reverse.js"></script>
+    <script src="spec/actions/revert.js"></script>
     <script src="spec/actions/split.js"></script>
     <script src="spec/actions/unrestrict_turn.js"></script>
 

test/index_packaged.html

@@ -54,6 +54,7 @@
     <script src="spec/actions/orthogonalize.js"></script>
     <script src="spec/actions/restrict_turn.js"></script>
     <script src="spec/actions/reverse.js"></script>
+    <script src="spec/actions/revert.js"></script>
     <script src="spec/actions/split.js"></script>
     <script src="spec/actions/straighten.js"></script>
     <script src="spec/actions/unrestrict_turn.js"></script>

test/spec/actions/revert.js

@@ -0,0 +1,11 @@
+describe('iD.actions.Revert', function() {
+    it('reverts an entity', function() {
+        var n1 = iD.Node({id: 'n' }),
+            n2 = n1.update({}),
+            graph = iD.Graph([n1]).replace(n2);
+
+        expect(graph.entity('n')).to.equal(n2);
+        graph = iD.actions.Revert(n2)(graph)
+        expect(graph.entity('n')).to.equal(n1);
+    });
+});