Add tests, remove unused code, encapsulate repeated code in functions

test/spec/ol/render/canvas.test.js

@@ -0,0 +1,25 @@
+goog.provide('ol.test.render.canvas');
+
+
+describe('ol.render.canvas', function() {
+
+  describe('rotateAtOffset', function() {
+    it('rotates a canvas at an offset point', function() {
+      var context = {
+        translate: sinon.spy(),
+        rotate: sinon.spy()
+      };
+      ol.render.canvas.rotateAtOffset(context, Math.PI, 10, 10);
+      expect(context.translate.callCount).to.be(2);
+      expect(context.translate.firstCall.args).to.eql([10, 10]);
+      expect(context.translate.secondCall.args).to.eql([-10, -10]);
+      expect(context.rotate.callCount).to.be(1);
+      expect(context.rotate.firstCall.args).to.eql([Math.PI]);
+    });
+  });
+
+});
+
+
+goog.require('ol.render');
+goog.require('ol.render.canvas');