FFM-10325 Fix issue with detecting empty evaluation/target metrics (#101)

Author: erdirowlands

examples/getting_started/package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "@harnessio/ff-nodejs-server-sdk",
-  "version": "1.4.0",
+  "version": "1.4.1",
   "description": "Feature flags SDK for NodeJS environments",
   "main": "dist/cjs/index.js",
   "module": "dist/esm/index.mjs",

package-lock.json

@@ -101,11 +101,6 @@ export const MetricsProcessor = (
   };
 
   const _summarize = (): Metrics | unknown => {
-    if (!data) {
-      log.debug('No metrics data!');
-      return;
-    }
-
     const targetData: TargetData[] = [];
     const metricsData: MetricsData[] = [];
 
@@ -184,30 +179,34 @@ export const MetricsProcessor = (
 
   const _send = (): void => {
     if (closed) {
+      log.debug('SDK has been closed before metrics can be sent');
+      return;
+    }
+
+    if (data.size == 0) {
+      log.debug('No metrics to send in this interval');
       return;
     }
 
     const metrics: Metrics = _summarize();
 
-    if (metrics && metrics.metricsData.length && metrics.targetData.length) {
-      log.debug('Start sending metrics data');
-      api
-        .postMetrics(environment, cluster, metrics)
-        .then((response) => {
-          log.debug('Metrics server returns: ', response.status);
-          infoMetricsSuccess(log);
-          if (response.status >= 400) {
-            log.error(
-              'Error while sending metrics data with status code: ',
-              response.status,
-            );
-          }
-        })
-        .catch((error: Error) => {
-          warnPostMetricsFailed(`${error}`, log);
-          log.debug('Metrics server returns error: ', error);
-        });
-    }
+    log.debug('Start sending metrics data');
+    api
+      .postMetrics(environment, cluster, metrics)
+      .then((response) => {
+        log.debug('Metrics server returns: ', response.status);
+        infoMetricsSuccess(log);
+        if (response.status >= 400) {
+          log.error(
+            'Error while sending metrics data with status code: ',
+            response.status,
+          );
+        }
+      })
+      .catch((error: Error) => {
+        warnPostMetricsFailed(`${error}`, log);
+        log.debug('Metrics server returns error: ', error);
+      });
   };
 
   const start = (): void => {

package.json

@@ -143,7 +143,6 @@ export class StreamProcessor {
 
         res
           .on('data', (data) => {
-            debugStreamEventReceived(this.log);
             this.processData(data);
           })
           .on('close', () => {
@@ -166,11 +165,16 @@ export class StreamProcessor {
 
   private processData(data: any): void {
     const lines = data.toString().split(/\r?\n/);
+    if (lines[0].startsWith(":")) {
+      this.log.debug("SSE Heartbeat received")
+      return;
+    }
     lines.forEach((line) => this.processLine(line));
   }
 
   private processLine(line: string): void {
     if (line.startsWith('data:')) {
+      debugStreamEventReceived(this.log);
       this.log.debug('SSE GOT:', line.substring(5));
       const msg = JSON.parse(line.substring(5));
 

src/metrics.ts

@@ -1 +1 @@
-export const VERSION = '1.4.0';
+export const VERSION = '1.4.1';