From ebed67b4935b7fd61f627c5e099812d2fb46f23b Mon Sep 17 00:00:00 2001
From: Abinet <adebele@cisco.com>
Date: Mon, 11 Sep 2023 14:29:57 -0700
Subject: [PATCH] allow adding custom data to event

---
 .../web/web-vitals/src/web-vitals.ts          | 59 ++++++++++++-------
 1 file changed, 38 insertions(+), 21 deletions(-)

diff --git a/pkgs/instrumentations/web/web-vitals/src/web-vitals.ts b/pkgs/instrumentations/web/web-vitals/src/web-vitals.ts
index 2946b9426..938e508c6 100644
--- a/pkgs/instrumentations/web/web-vitals/src/web-vitals.ts
+++ b/pkgs/instrumentations/web/web-vitals/src/web-vitals.ts
@@ -18,41 +18,40 @@ import {
   InstrumentationBase,
   InstrumentationConfig,
 } from '@opentelemetry/sandbox-instrumentation';
-import { events } from '@opentelemetry/sandbox-sdk-events';
+import { Event } from '@opentelemetry/sandbox-api-events';
+import { EventEmitter } from '@opentelemetry/sandbox-sdk-events';
 import { ReportOpts, Metric } from 'web-vitals';
 import * as webVitals from 'web-vitals';
 
-import { VERSION } from './version';
+import { WebVitalsInstrumentationConfig, ApplyCustomEventDataFunction } from './types';
 
 const DEFAULT_METRIC_NAMES: Metric['name'][] = ['CLS', 'FID', 'LCP'];
-
-
-export interface WebVitalsInstrumentationConfig
-  extends InstrumentationConfig,
-    ReportOpts {
-  /**
-   * List of web-vitals to instrument ('CLS', 'FID', 'LCP', 'FCP', 'INP', 'TTFB')
-   * By default 'CLS', 'FID and 'LCP' are instrumented
-   */
-  metricsToTrack?: Metric['name'][];
-}
+const VERSION = '1';
 
 export class WebVitalsInstrumentation extends InstrumentationBase {
-  private _metrics: Metric['name'][];
+  applyCustomEventData: ApplyCustomEventDataFunction | undefined = undefined;
+  emitter: EventEmitter | null = null;
+  private _metricsToTrack: Metric['name'][];
   private _reportAllChanges: ReportOpts['reportAllChanges'];
   private _durationThreshold: ReportOpts['durationThreshold'];
 
+
   constructor(config?: WebVitalsInstrumentationConfig) {
+
     super('@opentelemetry/sandbox-instrumentation-web-vitals', VERSION, config);
-    this._metrics = config?.metrics || DEFAULT_METRIC_NAMES;
+    this._metricsToTrack = config?.metricsToTrack || DEFAULT_METRIC_NAMES;
     this._reportAllChanges = config?.reportAllChanges;
     this._durationThreshold = config?.durationThreshold;
+    this.applyCustomEventData = config?.applyCustomEventData;
+    this.emitter = new EventEmitter(
+        'web-vitals',
+         VERSION,
+        'browser'
+    );
   }
 
   private _onReport = (metric: Metric) => {
-    const eventEmitter = events.getEventEmitter('web-vitals', VERSION);
-    let webVitalEvent
-    eventEmitter.emit({
+    const webVitalEvent = {
       name: 'web_vital',
       data: {
         value: metric.value,
@@ -61,12 +60,16 @@ export class WebVitalsInstrumentation extends InstrumentationBase {
         rating: metric.rating,
         navigationType: metric.navigationType,
         name: metric.name,
-      },
-    });
+      }
+    };
+    if(this.applyCustomEventData) {
+      this._applyCustomEventData(webVitalEvent,this.applyCustomEventData);
+    }
+    this.emitter.emit(webVitalEvent);
   };
 
   override enable() {
-    this._metrics.forEach(metric => {
+    this._metricsToTrack.forEach(metric => {
       webVitals[`on${metric}`](this._onReport, {
         reportAllChanges: this._reportAllChanges,
         durationThreshold: this._durationThreshold,
@@ -75,4 +78,18 @@ export class WebVitalsInstrumentation extends InstrumentationBase {
   }
 
   init(): void {}
+  /**
+   *
+   * @param event
+   * @param applyCustomEventData
+   * Add custom data to the event
+   */
+  _applyCustomEventData(
+      event: Event,
+      applyCustomEventData: ApplyCustomEventDataFunction | undefined,
+  ) {
+    if (applyCustomEventData) {
+      applyCustomEventData(event)
+    }
+  }
 }