Extract AddMidpoint action

index.html

@@ -73,6 +73,7 @@
         <script src='js/id/ui/key_reference.js'></script>
 
         <script src='js/id/actions.js'></script>
+        <script src="js/id/actions/add_midpoint.js"></script>
         <script src='js/id/actions/add_node.js'></script>
         <script src='js/id/actions/add_way.js'></script>
         <script src='js/id/actions/add_way_node.js'></script>

js/id/actions/add_midpoint.js

@@ -0,0 +1,11 @@
+iD.actions.AddMidpoint = function(midpoint, node) {
+    return function(graph) {
+        graph = graph.replace(node.move(midpoint.loc));
+
+        midpoint.ways.forEach(function(way) {
+            graph = graph.replace(graph.entity(way.id).addNode(node.id, way.index));
+        });
+
+        return graph;
+    };
+};

js/id/behavior/drag_midpoint.js

@@ -8,14 +8,9 @@ iD.behavior.DragMidpoint = function(mode) {
             return projection(d.loc);
         })
         .on('start', function(d) {
-            var node = iD.Node({loc: d.loc});
+            var node = iD.Node();
 
-            var args = [iD.actions.AddNode(node)];
-            for (var i = 0; i < d.ways.length; i++) {
-                args.push(iD.actions.AddWayNode(d.ways[i].id, node.id, d.ways[i].index));
-            }
-
-            history.perform.apply(history, args);
+            history.perform(iD.actions.AddMidpoint(d, node));
 
             var vertex = d3.selectAll('.vertex')
                 .filter(function(data) { return data.id === node.id; });

test/index.html

@@ -68,6 +68,7 @@
     <script src='../js/id/ui/confirm.js'></script>
 
     <script src='../js/id/actions.js'></script>
+    <script src="../js/id/actions/add_midpoint.js"></script>
     <script src='../js/id/actions/add_node.js'></script>
     <script src='../js/id/actions/add_way.js'></script>
     <script src='../js/id/actions/add_way_node.js'></script>
@@ -137,6 +138,7 @@
     <!-- include spec files here... -->
     <script src="spec/lib/d3.keybinding.js"></script>
 
+    <script src="spec/actions/add_midpoint.js"></script>
     <script src="spec/actions/add_node.js"></script>
     <script src="spec/actions/add_way.js"></script>
     <script src="spec/actions/change_entity_tags.js"></script>

test/index_packaged.html

@@ -32,6 +32,7 @@
     <!-- include spec files here... -->
     <script src="spec/lib/d3.keybinding.js"></script>
 
+    <script src="spec/actions/add_midpoint.js"></script>
     <script src="spec/actions/add_node.js"></script>
     <script src="spec/actions/add_way.js"></script>
     <script src="spec/actions/change_entity_tags.js"></script>

test/spec/actions/add_midpoint.js

@@ -0,0 +1,22 @@
+describe("iD.actions.AddMidpoint", function () {
+    it("adds the node at the midpoint location", function () {
+        var node = iD.Node(),
+            midpoint = {loc: [1, 2], ways: []},
+            graph = iD.actions.AddMidpoint(midpoint, node)(iD.Graph());
+
+        expect(graph.entity(node.id).loc).to.eql([1, 2]);
+    });
+
+    it("adds the node to all ways at the respective indexes", function () {
+        var node = iD.Node(),
+            a = iD.Node(),
+            b = iD.Node(),
+            w1 = iD.Way(),
+            w2 = iD.Way({nodes: [a.id, b.id]}),
+            midpoint = {loc: [1, 2], ways: [{id: w1.id, index: 0}, {id: w2.id, index: 1}]},
+            graph = iD.actions.AddMidpoint(midpoint, node)(iD.Graph([a, b, w1, w2]));
+
+        expect(graph.entity(w1.id).nodes).to.eql([node.id]);
+        expect(graph.entity(w2.id).nodes).to.eql([a.id, node.id, b.id]);
+    });
+});