Simplify; test; fix

js/id/graph/entity.js

@@ -129,11 +129,11 @@ iD.Way = iD.Entity.extend({
     nodes: [],
 
     isOneWay: function() {
-        return !!(this.tags.oneway && this.tags.oneway === 'yes');
+        return this.tags.oneway === 'yes';
     },
 
     isClosed: function() {
-        return (!this.nodes.length) || this.nodes[this.nodes.length - 1] === this.nodes[0];
+        return this.nodes.length > 0 && this.nodes[this.nodes.length - 1] === this.nodes[0];
     },
 
     // a way is an area if:
@@ -143,14 +143,11 @@ iD.Way = iD.Entity.extend({
     //   - doesn't have area=no
     //   - doesn't have highway tag
     isArea: function() {
-        return (this.tags.area && this.tags.area === 'yes') ||
+        return this.tags.area === 'yes' ||
             (this.isClosed() &&
-                 // area-ness is disabled
-                 (!this.tags.area || this.tags.area !== 'no') &&
-                 // Tags that disable area-ness unless they are accompanied by
-                 // area=yes
-                 !this.tags.highway &&
-                 !this.tags.barrier);
+                this.tags.area !== 'no' &&
+                !this.tags.highway &&
+                !this.tags.barrier);
     }
 });
 

test/spec/graph/way.js

@@ -52,6 +52,10 @@ describe('iD.Way', function() {
     });
 
     describe('#isClosed', function() {
+        it('returns false when the way has no nodes', function() {
+            expect(iD.Way().isClosed()).to.equal(false);
+        });
+
         it('returns false when the way ends are not equal', function() {
             expect(iD.Way({nodes: ['n1', 'n2']}).isClosed()).to.equal(false);
         });
@@ -74,4 +78,26 @@ describe('iD.Way', function() {
             expect(iD.Way({tags: { oneway: 'yes' }}).isOneWay()).to.equal(true);
         });
     });
+
+    describe('#isArea', function() {
+        it('returns false when the way has no tags', function() {
+            expect(iD.Way().isArea()).to.equal(false);
+        });
+
+        it('returns true if the way has tag area=yes', function() {
+            expect(iD.Way({tags: { area: 'yes' }}).isArea()).to.equal(true);
+        });
+
+        it('returns true if the way is closed and has no tags', function() {
+            expect(iD.Way({nodes: ['n1', 'n1']}).isArea()).to.equal(true);
+        });
+
+        it('returns false if the way is closed and has tag area=no', function() {
+            expect(iD.Way({tags: { area: 'no' }, nodes: ['n1', 'n1']}).isArea()).to.equal(false);
+        });
+
+        it('returns false if the way is closed and has highway tag', function() {
+            expect(iD.Way({tags: { highway: 'residential' }, nodes: ['n1', 'n1']}).isArea()).to.equal(false);
+        });
+    });
 });