Method for removing cached transforms

src/ol/projection.js

@@ -266,6 +266,31 @@ ol.Projection.addTransform = function(source, destination, transformFn) {
 };
 
 
+/**
+ * Unregisters the conversion function to convert coordinates from the source
+ * projection to the destination projection.  This method is used to clean up
+ * cached transforms during testing.
+ *
+ * @param {ol.Projection} source Source projection.
+ * @param {ol.Projection} destination Destination projection.
+ * @return {ol.TransformFunction} transformFn The unregistered transform.
+ */
+ol.Projection.removeTransform = function(source, destination) {
+  var sourceCode = source.getCode();
+  var destinationCode = destination.getCode();
+  var transforms = ol.Projection.transforms_;
+  goog.asserts.assert(sourceCode in transforms);
+  goog.asserts.assert(destinationCode in transforms[sourceCode]);
+  var transform = transforms[sourceCode][destinationCode];
+  delete transforms[sourceCode][destinationCode];
+  var keys = goog.object.getKeys(transforms[sourceCode]);
+  if (keys.length == 0) {
+    delete transforms[sourceCode];
+  }
+  return transform;
+};
+
+
 /**
  * @param {string} code Code which is a combination of authority and identifier
  *   such as “EPSG:4326”.

test/spec/ol/projection.test.js

@@ -131,6 +131,25 @@ describe('ol.Projection', function() {
       var transform = ol.Projection.getTransformFromCodes(
           'GOOGLE', 'EPSG:4326');
       expect(typeof transform).toBe('function');
+  });
+
+  describe('ol.Projection.removeTransform()', function() {
+
+    var extent = new ol.Extent(-180, -90, 180, 90);
+    var units = ol.ProjectionUnits.DEGREES;
+
+    it('removes functions cached by addTransform', function() {
+      var foo = new ol.Projection('foo', units, extent);
+      var bar = new ol.Projection('bar', units, extent);
+      var transform = function() {};
+      ol.Projection.addTransform(foo, bar, transform);
+      expect(ol.Projection.transforms_).not.toBeUndefined();
+      expect(ol.Projection.transforms_.foo).not.toBeUndefined();
+      expect(ol.Projection.transforms_.foo.bar).toBe(transform);
+
+      var removed = ol.Projection.removeTransform(foo, bar);
+      expect(removed).toBe(transform);
+      expect(ol.Projection.transforms_.foo).toBeUndefined();
     });
 
   });