fix(analytics) make handler loading more resilient

- Don't initialize handler's is their API key is not set
- Don't swallow exceptions when creating handlers
- Don't remove all handlers if an external one fails
- Dispose the analytics subsystem if no handlers are registered

react/features/analytics/functions.js

@@ -57,12 +57,15 @@ export function resetAnalytics() {
  * @param {Store} store - The redux store in which the specified {@code action} is being dispatched.
  * @returns {Promise} Resolves with the handlers that have been successfully loaded.
  */
-export function createHandlers({ getState }: { getState: Function }) {
+export async function createHandlers({ getState }: { getState: Function }) {
     getJitsiMeetGlobalNS().analyticsHandlers = [];
     window.analyticsHandlers = []; // Legacy support.
 
     if (!isAnalyticsEnabled(getState)) {
-        return Promise.resolve([]);
+        // Avoid all analytics processing if there are no handlers, since no event would be sent.
+        analytics.dispose();
+
+        return [];
     }
 
     const state = getState();
@@ -100,43 +103,47 @@ export function createHandlers({ getState }: { getState: Function }) {
     };
     const handlers = [];
 
+    if (amplitudeAPPKey) {
         try {
             const amplitude = new AmplitudeHandler(handlerConstructorOptions);
 
             analytics.amplitudeIdentityProps = amplitude.getIdentityProps();
 
             handlers.push(amplitude);
-    // eslint-disable-next-line no-empty
+        } catch (e) {
-    } catch (e) {}
+            logger.error('Failed to initialize Amplitude handler', e);
+        }
+    }
 
+    if (matomoEndpoint && matomoSiteID) {
         try {
             const matomo = new MatomoHandler(handlerConstructorOptions);
 
             handlers.push(matomo);
-    // eslint-disable-next-line no-empty
+        } catch (e) {
-    } catch (e) {}
+            logger.error('Failed to initialize Matomo handler', e);
-
-    return (
-        _loadHandlers(scriptURLs, handlerConstructorOptions)
-            .then(externalHandlers => {
-                handlers.push(...externalHandlers);
-                if (handlers.length === 0) {
-                    // Throwing an error in order to dispose the analytics in the catch clause due to the lack of any
-                    // analytics handlers.
-                    throw new Error('No analytics handlers created!');
         }
+    }
+
+    if (Array.isArray(scriptURLs) && scriptURLs.length > 0) {
+        let externalHandlers;
+
+        try {
+            externalHandlers = await _loadHandlers(scriptURLs, handlerConstructorOptions);
+            handlers.push(...externalHandlers);
+        } catch (e) {
+            logger.error('Failed to initialize external analytics handlers', e);
+        }
+    }
+
+    // Avoid all analytics processing if there are no handlers, since no event would be sent.
+    if (handlers.length === 0) {
+        analytics.dispose();
+    }
+
+    logger.info(`Initialized ${handlers.length} analytics handlers`);
 
     return handlers;
-            })
-            .catch(e => {
-                analytics.dispose();
-                if (handlers.length !== 0) {
-                    logger.error(e);
-                }
-
-                return [];
-            }));
-
 }
 
 /**