Support merging point + line

js/id/actions/merge.js

@@ -1,34 +1,35 @@
 iD.actions.Merge = function(ids) {
     function groupEntitiesByGeometry(graph) {
         var entities = ids.map(function(id) { return graph.entity(id); });
-        return _.extend({point: [], area: []}, _.groupBy(entities, function(entity) { return entity.geometry(graph); }));
+        return _.extend({point: [], area: [], line: [], relation: []},
+            _.groupBy(entities, function(entity) { return entity.geometry(graph); }));
     }
 
     var action = function(graph) {
         var geometries = groupEntitiesByGeometry(graph),
-            area = geometries.area[0],
+            target = geometries.area[0] || geometries.line[0],
             points = geometries.point;
 
         points.forEach(function(point) {
-            area = area.mergeTags(point.tags);
+            target = target.mergeTags(point.tags);
 
             graph.parentRelations(point).forEach(function(parent) {
-                graph = graph.replace(parent.replaceMember(point, area));
+                graph = graph.replace(parent.replaceMember(point, target));
             });
 
             graph = graph.remove(point);
         });
 
-        graph = graph.replace(area);
+        graph = graph.replace(target);
 
         return graph;
     };
 
     action.enabled = function(graph) {
         var geometries = groupEntitiesByGeometry(graph);
-        return geometries.area.length === 1 &&
-            geometries.point.length > 0 &&
-            (geometries.area.length + geometries.point.length) === ids.length;
+        return geometries.point.length > 0 &&
+            (geometries.area.length + geometries.line.length) === 1 &&
+            geometries.relation.length === 0;
     };
 
     return action;

test/spec/actions/merge.js

@@ -1,4 +1,23 @@
 describe("iD.actions.Merge", function () {
+    it("merges multiple points to a line", function () {
+        var graph = iD.Graph({
+                'a': iD.Node({id: 'a', tags: {a: 'a'}}),
+                'b': iD.Node({id: 'b', tags: {b: 'b'}}),
+                'w': iD.Way({id: 'w'}),
+                'r': iD.Relation({id: 'r', members: [{id: 'a', role: 'r', type: 'node'}]})
+            }),
+            action = iD.actions.Merge(['a', 'b', 'w']);
+
+        expect(action.enabled(graph)).to.be.true;
+
+        graph = action(graph);
+
+        expect(graph.entity('a')).to.be.undefined;
+        expect(graph.entity('b')).to.be.undefined;
+        expect(graph.entity('w').tags).to.eql({a: 'a', b: 'b'});
+        expect(graph.entity('r').members).to.eql([{id: 'w', role: 'r', type: 'way'}]);
+    });
+
     it("merges multiple points to an area", function () {
         var graph = iD.Graph({
                 'a': iD.Node({id: 'a', tags: {a: 'a'}}),