fix(component-factory): remove context event listeners on unmount (#319)

Author: tasseKATT

packages/picasso.js/src/core/component/__tests__/component-factory.spec.js

@@ -272,6 +272,22 @@ describe('Component', () => {
     });
   });
 
+  describe('unmount', () => {
+    let instance;
+
+    beforeEach(() => {
+      instance = createAndRenderComponent({
+        key: 'myKey',
+        eventListeners: [{ event: 'event1', listener: () => {} }, { event: 'event2', listener: () => {} }]
+      });
+    });
+
+    it('should remove event listeners from instance context', () => {
+      instance.unmount();
+      expect(instance.ctx.eventListeners).to.deep.equal([]);
+    });
+  });
+
   describe('getBrushedShapes', () => {
     let instance;
     let config;

packages/picasso.js/src/core/component/component-factory.js

@@ -153,9 +153,12 @@ function setUpEmitter(ctx, emitter, settings) {
 }
 
 function tearDownEmitter(ctx, emitter) {
-  (ctx.eventListeners || []).forEach(({ event, listener }) => {
-    emitter.removeListener(event, listener);
-  });
+  if (ctx.eventListeners) {
+    ctx.eventListeners.forEach(({ event, listener }) => {
+      emitter.removeListener(event, listener);
+    });
+    ctx.eventListeners.length = 0;
+  }
   ctx.emit = () => {};
 }