Hopefully, fix intermittent test failure

This seeks to fix the intermittent failure of the "MatrixClient rehydrated from
stored credentials" tests.

The problem appears to be that the 'load_completed' is sometimes taking a while
to come through from the dispatcher - or rather, it is taking a long time to
get *sent* to the dispatcher: the chain of `q().then().catch().done()` in
componentDidMount can take a while to happen.

As a workaround, give the test a few goes when waiting for us to start
syncing. It's not ideal to be poking into the internal state of MatrixChat like
this, but it'll do for now.

test/app-tests/loading.js

@@ -94,13 +94,13 @@ describe('loading:', function () {
         loadCompletePromise = loadCompleteDefer.promise;
 
         function onNewScreen(screen) {
-            console.log("newscreen "+screen);
+            console.log(Date.now() + " newscreen "+screen);
             if (!appLoaded) {
                 lastLoadedScreen = screen;
             } else {
                 var hash = '#/' + screen;
                 windowLocation.hash = hash;
-                console.log("browser URI now "+ windowLocation);
+                console.log(Date.now() + " browser URI now "+ windowLocation);
             }
         }
 
@@ -122,22 +122,22 @@ describe('loading:', function () {
         );
 
         function routeUrl(location, matrixChat) {
-            console.log("Routing URL "+location);
+            console.log(Date.now() + " Routing URL "+location);
             var fragparts = parseQsFromFragment(location);
             matrixChat.showScreen(fragparts.location.substring(1),
                                   fragparts.params);
         }
 
         // pause for a cycle, then simulate the window.onload handler
-        q.delay(0).then(() => {
+        window.setTimeout(() => {
-            console.log("simulating window.onload");
+            console.log(Date.now() + " simulating window.onload");
             routeUrl(windowLocation, matrixChat);
             appLoaded = true;
             if (lastLoadedScreen) {
                 onNewScreen(lastLoadedScreen);
                 lastLoadedScreen = null;
             }
-        }).done();
+        }, 0);
     }
 
     describe("Clean load with no stored credentials:", function() {
@@ -243,10 +243,8 @@ describe('loading:', function () {
 
             loadApp();
 
-            q.delay(1).then(() => {
+            return awaitSyncingSpinner(matrixChat).then(() => {
-                // we expect a spinner
+                // we got a sync spinner - let the sync complete
-                assertAtSyncingSpinner(matrixChat);
-
                 return httpBackend.flush();
             }).then(() => {
                 // once the sync completes, we should have a directory
@@ -266,10 +264,8 @@ describe('loading:', function () {
                 uriFragment: "#/room/!room:id",
             });
 
-            q.delay(1).then(() => {
+            return awaitSyncingSpinner(matrixChat).then(() => {
-                // we expect a spinner
+                // we got a sync spinner - let the sync complete
-                assertAtSyncingSpinner(matrixChat);
-
                 return httpBackend.flush();
             }).then(() => {
                 // once the sync completes, we should have a room view
@@ -300,12 +296,9 @@ describe('loading:', function () {
 
                 return httpBackend.flush();
             }).then(() => {
-                // Wait for another trip around the event loop for the UI to update
+                return awaitSyncingSpinner(matrixChat);
-                return q.delay(1);
             }).then(() => {
-                // now we should have a spinner with a logout link
+                // we got a sync spinner - let the sync complete
-                assertAtSyncingSpinner(matrixChat);
-
                 httpBackend.when('GET', '/sync').respond(200, {});
                 return httpBackend.flush();
             }).then(() => {
@@ -338,12 +331,8 @@ describe('loading:', function () {
 
                 return httpBackend.flush();
             }).then(() => {
-                // Wait for another trip around the event loop for the UI to update
+                return awaitSyncingSpinner(matrixChat);
-                return q.delay(1);
             }).then(() => {
-                // now we should have a spinner with a logout link
-                assertAtSyncingSpinner(matrixChat);
-
                 httpBackend.when('GET', '/sync').check(function(req) {
                     expect(req.path).toMatch(new RegExp("^https://homeserver/"));
                 }).respond(200, {});
@@ -377,12 +366,8 @@ describe('loading:', function () {
 
                 return httpBackend.flush();
             }).then(() => {
-                // Wait for another trip around the event loop for the UI to update
+                return awaitSyncingSpinner(matrixChat);
-                return q.delay(1);
             }).then(() => {
-                // now we should have a spinner with a logout link
-                assertAtSyncingSpinner(matrixChat);
-
                 httpBackend.when('GET', '/sync').respond(200, {});
                 return httpBackend.flush();
             }).then(() => {
@@ -448,6 +433,32 @@ function assertAtLoadingSpinner(matrixChat) {
 
 // we've got login creds, and are waiting for the sync to finish.
 // the page includes a logout link.
+function awaitSyncingSpinner(matrixChat, retryLimit, retryCount) {
+    if (retryLimit === undefined) {
+        retryLimit = 5;
+    }
+    if (retryCount === undefined) {
+        retryCount = 0;
+    }
+
+    if (matrixChat.state.loading) {
+        console.log(Date.now() + " Awaiting sync spinner: still loading.");
+        if (retryCount >= retryLimit) {
+            throw new Error("MatrixChat still not loaded after " +
+                            retryCount + " tries");
+        }
+        return q.delay(0).then(() => {
+            return awaitSyncingSpinner(matrixChat, retryLimit, retryCount + 1);
+        });
+    }
+
+    console.log(Date.now() + " Awaiting sync spinner: load complete.");
+
+    // state looks good, check the rendered output
+    assertAtSyncingSpinner(matrixChat);
+    return q();
+}
+
 function assertAtSyncingSpinner(matrixChat) {
     var domComponent = ReactDOM.findDOMNode(matrixChat);
     expect(domComponent.className).toEqual("mx_MatrixChat_splash");