fixed bug with removing change listener of proxied prop

Author: c58

lib/utils.js

@@ -173,12 +173,13 @@ export function _createProperty(initValue) {
     prop.addChangeListener = toProp.addChangeListener;
     prop.emitChange = toProp.emitChange;
     _each(emitter.listeners('change'), cb => toProp.addChangeListener(cb));
-    emitter = null;
+    emitter = toProp.__emitter;
     store = null;
   };
 
   prop.version = ++_propertyVersionId;
   prop.isProperty = true;
+  prop.__emitter = emitter;
   return prop;
 }
 

test/both/utils.test.js

@@ -111,7 +111,7 @@ describe('Utils', function () {
       var cb = sinon.spy();
       const propA = utils._createProperty('val');
       const toPropB = utils._createProperty('val2');
-      propA.addChangeListener(cb);
+      const stopper = propA.addChangeListener(cb);
       propA.proxyTo(toPropB);
       propA().should.be.equal('val2');
       toPropB().should.be.equal('val2');
@@ -122,6 +122,10 @@ describe('Utils', function () {
       toPropB('val3');
       cb.should.have.callCount(1);
       toPropB().should.be.equal('val3');
+      stopper();
+      toPropB('val4');
+      cb.should.have.callCount(1);
+      toPropB().should.be.equal('val4');
     });
   });