Clear dispatch token (#52)

It seems that in certain versions of React it was possible for
`componentWillMount` to be called more than once. facebook/react#6613

If that happened to a `connect`ed component, it would cause
`dispatcher.unregister` to be called again with a token that was already
unregistered causing an exception.

This `null`s the token field so unregister can only be called once for a
given token.

CHANGELOG.md

@@ -1,3 +1,6 @@
+## 2.2.1
+* Fix a potential bug in connect/StoreDependencyMixin that could cause an exeption in `componentWillUnmount`
+
 ## 2.2.0
 * Component generated by `connect` inherits propTypes unrelated to the store dependencies from the BaseComponent
 

bower.json

@@ -1,6 +1,6 @@
 {
   "name": "general-store",
-  "version": "2.2.0",
+  "version": "2.2.1",
   "homepage": "https://github.com/HubSpot/general-store",
   "authors": [
     "Colby Rabideau <crabideau@hubspot.com>"

package.json

@@ -1,6 +1,6 @@
 {
   "name": "general-store",
-  "version": "2.2.0",
+  "version": "2.2.1",
   "description": "Simple, flexible store implementation for Flux.",
   "main": "lib/GeneralStore.js",
   "scripts": {

src/dependencies/StoreDependencyMixin.js

@@ -78,8 +78,10 @@ export default function StoreDependencyMixin(
     },
 
     componentWillUnmount(): void {
-      if (dispatcher && this.__dispatchToken) {
-        dispatcher.unregister(this.__dispatchToken);
+      const dispatchToken = this.__dispatchToken;
+      if (dispatcher && dispatchToken) {
+        this.__dispatchToken = null;
+        dispatcher.unregister(dispatchToken);
       }
     },
 

src/dependencies/connect.js

@@ -65,8 +65,10 @@ export default function connect(
       }
 
       componentWillUnmount(): void {
-        if (dispatcher && this.dispatchToken) {
-          dispatcher.unregister(this.dispatchToken);
+        const dispatchToken = this.dispatchToken;
+        if (dispatcher && dispatchToken) {
+          this.dispatchToken = null;
+          dispatcher.unregister(dispatchToken);
         }
       }