Merge pull request #207 from zendesk/wxing/clear-request-handlers

Clear handlers of request:X.done and request:X.fail of the request

Author: yaraya24

lib/client.js

@@ -556,13 +556,23 @@ export default class Client {
         options = { url: options }
       }
 
-      this.on(requestKey + '.done', (evt) => {
+      const doneEventKey = `${requestKey}.done`
+      const failEventKey = `${requestKey}.fail`
+
+      const doneHandler = (evt) => {
         resolve.apply(this, evt.responseArgs)
-      })
+        this.off(failEventKey, failHandler)
+        this.off(doneEventKey, doneHandler)
+      }
 
-      this.on(requestKey + '.fail', (evt) => {
+      const failHandler = (evt) => {
         reject.apply(this, evt.responseArgs)
-      })
+        this.off(failEventKey, failHandler)
+        this.off(doneEventKey, doneHandler)
+      }
+
+      this.on(doneEventKey, doneHandler)
+      this.on(failEventKey, failHandler)
 
       this.postMessage(requestKey, options)
     })