Merge pull request #102 from jamesreggio/add-appstate-callbacks

Abandon auth dance if app becomes active without a callback URL

lib/platforms/react-native.js

@@ -1,12 +1,26 @@
-import { Linking } from 'react-native'; // eslint-disable-line import/no-unresolved, max-len
+import { Linking, AppState } from 'react-native'; // eslint-disable-line import/no-unresolved, max-len
 
-let previousOnLinkChange;
+let appStateTimeout;
+let previousLinkingCallback;
+let previousAppStateCallback;
 
-export const dance = (authUrl) => {
-  if (previousOnLinkChange) {
-    Linking.removeEventListener('url', previousOnLinkChange);
+const cleanup = () => {
+  clearTimeout(appStateTimeout);
+
+  if (previousLinkingCallback) {
+    Linking.removeEventListener('url', previousLinkingCallback);
+    previousLinkingCallback = null;
   }
 
+  if (previousAppStateCallback) {
+    AppState.removeEventListener('change', previousAppStateCallback);
+    previousAppStateCallback = null;
+  }
+};
+
+export const dance = (authUrl) => {
+  cleanup();
+
   return Linking.openURL(authUrl)
     .then(() => new Promise((resolve, reject) => {
       const handleUrl = (url) => {
@@ -17,15 +31,26 @@ export const dance = (authUrl) => {
         }
       };
 
-      const onLinkChange = ({ url }) => {
-        Linking.removeEventListener('url', onLinkChange);
-        previousOnLinkChange = undefined;
+      const linkingCallback = ({ url }) => {
+        cleanup();
         handleUrl(url);
       };
 
-      Linking.addEventListener('url', onLinkChange);
+      Linking.addEventListener('url', linkingCallback);
+      previousLinkingCallback = linkingCallback;
+
+      const appStateCallback = (state) => {
+        // Give time for Linking event to fire.
+        appStateTimeout = setTimeout(() => {
+          if (state === 'active') {
+            cleanup();
+            reject('cancelled');
+          }
+        }, 100);
+      };
 
-      previousOnLinkChange = onLinkChange;
+      AppState.addEventListener('change', appStateCallback);
+      previousAppStateCallback = appStateCallback;
     }));
 };