Add Event Loss Logging Using Custom Logger Interface (#467)

Diff for adding Custom Logger Interface
statsig-io/private-js-client-sdk#466

This Diff added more event loss logging using the custom interface

Author: weihao-statsig

src/StatsigClient.ts

@@ -771,13 +771,13 @@ export default class StatsigClient implements IHasStatsigInternal, IStatsig {
       }
       if (typeof eventName !== 'string' || eventName.length === 0) {
         OutputLogger.error(
-          'Event not logged. No valid eventName passed.',
+          'statsigSDK> Event not logged. No valid eventName passed.',
         );
         return;
       }
       if (this.shouldTrimParam(eventName, MAX_VALUE_SIZE)) {
         OutputLogger.info(
-          'eventName is too long, trimming to ' +
+          'statsigSDK> eventName is too long, trimming to ' +
             MAX_VALUE_SIZE +
             ' characters.',
         );
@@ -788,12 +788,12 @@ export default class StatsigClient implements IHasStatsigInternal, IStatsig {
         this.shouldTrimParam(value, MAX_VALUE_SIZE)
       ) {
         OutputLogger.info(
-          'value is too long, trimming to ' + MAX_VALUE_SIZE + '.',
+          'statsigSDK> value is too long, trimming to ' + MAX_VALUE_SIZE + '.',
         );
         value = value.substring(0, MAX_VALUE_SIZE);
       }
       if (this.shouldTrimParam(metadata, MAX_OBJ_SIZE)) {
-        OutputLogger.info('metadata is too big. Dropping the metadata.');
+        OutputLogger.info('statsigSDK> metadata is too big. Dropping the metadata.');
         metadata = { error: 'not logged due to size too large' };
       }
       const event = new LogEvent(eventName);
@@ -1322,20 +1322,20 @@ export default class StatsigClient implements IHasStatsigInternal, IStatsig {
     }
     if (this.shouldTrimParam(user.userID ?? null, MAX_VALUE_SIZE)) {
       OutputLogger.info(
-        'User ID is too large, trimming to ' + MAX_VALUE_SIZE + 'characters',
+        'statsigSDK> User ID is too large, trimming to ' + MAX_VALUE_SIZE + 'characters',
       );
       user.userID = user.userID?.toString().substring(0, MAX_VALUE_SIZE);
     }
     if (this.shouldTrimParam(user, MAX_OBJ_SIZE)) {
       user.custom = {};
       if (this.shouldTrimParam(user, MAX_OBJ_SIZE)) {
         OutputLogger.info(
-          'User object is too large, only keeping the user ID.',
+          'statsigSDK> User object is too large, only keeping the user ID.',
         );
         user = { userID: user.userID };
       } else {
         OutputLogger.info(
-          'User object is too large, dropping the custom property.',
+          'statsigSDK> User object is too large, dropping the custom property.',
         );
       }
     }
@@ -1366,7 +1366,7 @@ export default class StatsigClient implements IHasStatsigInternal, IStatsig {
     const prefetchUsers = args.prefetchUsers ?? [];
     const timeout = args.timeout ?? this.options.getInitTimeoutMs();
     if (prefetchUsers.length > 5) {
-      OutputLogger.info('Cannot prefetch more than 5 users.');
+      OutputLogger.info('statsigSDK> Cannot prefetch more than 5 users.');
     }
 
     const keyedPrefetchUsers = this.normalizePrefetchUsers(prefetchUsers)

src/StatsigLogger.ts

@@ -292,7 +292,7 @@ export default class StatsigLogger {
   ): void {
     this.logGenericEvent(DEFAULT_VALUE_WARNING, user, message, metadata);
     this.loggedErrors.add(message);
-    OutputLogger.error(message);
+    OutputLogger.error(`statsigSDK> ${message}`);
   }
 
   public logAppError(
@@ -472,7 +472,8 @@ export default class StatsigLogger {
           throw response;
         }
       })
-      .catch(() => {
+      // eslint-disable-next-line @typescript-eslint/no-unused-vars
+      .catch((error) => {
         this.addFailedRequest({ events: oldQueue, statsigMetadata: this.sdkInternal.getStatsigMetadata(), time: Date.now() });
       })
       .finally(async () => {
@@ -554,6 +555,7 @@ export default class StatsigLogger {
         }
       }
     } catch (e) {
+      OutputLogger.error("statsigSDK> sendSavedRequests ", e as Error);
       this.sdkInternal.getErrorBoundary().logError('sendSavedRequests', e);
     } finally {
       this.clearLocalStorageRequests();

src/StatsigNetwork.ts

@@ -3,6 +3,7 @@ import { IHasStatsigInternal } from './StatsigClient';
 import StatsigRuntime from './StatsigRuntime';
 import { StatsigUser } from './StatsigUser';
 import Diagnostics from './utils/Diagnostics';
+import OutputLogger from './utils/OutputLogger';
 
 export enum StatsigEndpoint {
   Initialize = 'initialize',
@@ -159,16 +160,20 @@ export default class StatsigNetwork {
       .then((localRes) => {
         res = localRes;
         if (!res.ok) {
+          const errorMessage = `Request to ${endpointName} failed with status ${res.status}`; 
+          OutputLogger.error(`statsigSDK> ${errorMessage}`);
           return Promise.reject(
             new Error(
-              `Request to ${endpointName} failed with status ${res.status}`,
+              errorMessage,
             ),
           );
         }
 
         if (typeof res.data !== 'object') {
+          const errorMessage = `Request to ${endpointName} received invalid response type. Expected 'object' but got '${typeof res.data}'`;
+          OutputLogger.error(`statsigSDK> ${errorMessage}`);
           const error = new Error(
-            `Request to ${endpointName} received invalid response type. Expected 'object' but got '${typeof res.data}'`,
+            errorMessage,
           );
           this.sdkInternal
             .getErrorBoundary()
@@ -365,6 +370,13 @@ export default class StatsigNetwork {
       })
       .catch((e) => {
         diagnostics?.end(this.getDiagnosticsData(res, attempt, e));
+        const errorMessage = `statsigSDK> Error occurred while posting to endpoint: ${e.message}\n` +
+              `Error Details: ${JSON.stringify(e)}\n` +
+              `Endpoint: ${endpointName}\n` +
+              `Attempt: ${attempt}\n` +
+              `Retry Limit: ${retryLimit}\n` +
+              `Backoff: ${backoff}`;
+        OutputLogger.error(errorMessage);
         if (attempt < retryLimit && isRetryCode) {
           return new Promise<NetworkResponse>((resolve, reject) => {
             setTimeout(() => {

src/__tests__/OutputLogger.test.ts

@@ -35,14 +35,14 @@ describe('Output logger Interface', () => {
             client.logEvent('');
             if (level === LogLevel.ERROR) {
                 expect(errors).toContainEqual(
-                    'Event not logged. No valid eventName passed.',
+                    'statsigSDK> Event not logged. No valid eventName passed.',
                 );
             }
 
             client.logEvent('a'.repeat(100));
             if (level == LogLevel.INFO) {
                 expect(infos).toContainEqual(
-                    'eventName is too long, trimming to ' + MAX_VALUE_SIZE + ' characters.',
+                    'statsigSDK> eventName is too long, trimming to ' + MAX_VALUE_SIZE + ' characters.',
                 );
             }
         }