Extract Entity#isUsed

js/id/core/entity.js

@@ -99,6 +99,11 @@ iD.Entity.prototype = {
         return this.extent(resolver).intersects(extent);
     },
 
+    isUsed: function(resolver) {
+        return _.without(Object.keys(this.tags), 'area').length > 0 ||
+            resolver.parentRelations(this).length > 0;
+    },
+
     // Returns the (possibly negative) area of the entity in square pixels at an
     // arbitrary unspecified zoom level -- so basically, only useful for relative
     // comparisons.

js/id/ui/inspector.js

@@ -53,16 +53,12 @@ iD.ui.Inspector = function(context) {
                 presetLayer.call(presetList);
             });
 
-        var unused =
-            _.without(Object.keys(entity.tags), 'area').length === 0 &&
-            context.graph().parentRelations(entity).length === 0;
-
-        if (unused) {
-            panewrap.style('right', '-100%');
-            presetLayer.call(presetList);
-        } else {
+        if (entity.isUsed(context.graph())) {
             panewrap.style('right', '-0%');
             tagLayer.call(entityEditor);
+        } else {
+            panewrap.style('right', '-100%');
+            presetLayer.call(presetList);
         }
     }
 

test/spec/core/entity.js

@@ -144,6 +144,33 @@ describe('iD.Entity', function () {
         });
     });
 
+    describe("#isUsed", function () {
+        it("returns false for an entity without tags", function () {
+            var node = iD.Node(),
+                graph = iD.Graph([node]);
+            expect(node.isUsed(graph)).to.equal(false);
+        });
+
+        it("returns true for an entity with tags", function () {
+            var node = iD.Node({tags: {foo: 'bar'}}),
+                graph = iD.Graph([node]);
+            expect(node.isUsed(graph)).to.equal(true);
+        });
+
+        it("returns false for an entity with only an area=yes tag", function () {
+            var node = iD.Node({tags: {area: 'yes'}}),
+                graph = iD.Graph([node]);
+            expect(node.isUsed(graph)).to.equal(false);
+        });
+
+        it("returns true for an entity that is a relation member", function () {
+            var node = iD.Node(),
+                relation = iD.Relation({members: [{id: node.id}]}),
+                graph = iD.Graph([node, relation]);
+            expect(node.isUsed(graph)).to.equal(true);
+        });
+    });
+
     describe("#hasDeprecatedTags", function () {
         it("returns false if entity has no tags", function () {
             expect(iD.Entity().deprecatedTags()).to.eql({});