feat(rum): add trackWebVitals config to opt out of initial view metrics

packages/rum-core/src/domain/configuration/configuration.spec.ts

@@ -369,6 +369,28 @@ describe('validateAndBuildRumConfiguration', () => {
     })
   })
 
+  describe('trackWebVitals', () => {
+    it('defaults to true', () => {
+      expect(validateAndBuildRumConfiguration(DEFAULT_INIT_CONFIGURATION)!.trackWebVitals).toBeTrue()
+    })
+
+    it('is set to provided value', () => {
+      expect(
+        validateAndBuildRumConfiguration({ ...DEFAULT_INIT_CONFIGURATION, trackWebVitals: true })!.trackWebVitals
+      ).toBeTrue()
+      expect(
+        validateAndBuildRumConfiguration({ ...DEFAULT_INIT_CONFIGURATION, trackWebVitals: false })!.trackWebVitals
+      ).toBeFalse()
+    })
+
+    it('the provided value is cast to boolean', () => {
+      expect(
+        validateAndBuildRumConfiguration({ ...DEFAULT_INIT_CONFIGURATION, trackWebVitals: 'foo' as any })!
+          .trackWebVitals
+      ).toBeTrue()
+    })
+  })
+
   describe('trackResources', () => {
     it('defaults to true', () => {
       expect(validateAndBuildRumConfiguration(DEFAULT_INIT_CONFIGURATION)!.trackResources).toBeTrue()
@@ -535,6 +557,7 @@ describe('serializeRumConfiguration', () => {
       trackUserInteractions: true,
       actionNameAttribute: 'test-id',
       trackViewsManually: true,
+      trackWebVitals: true,
       trackResources: true,
       trackLongTasks: true,
       remoteConfigurationId: '123',
@@ -556,6 +579,7 @@ describe('serializeRumConfiguration', () => {
                 | 'remoteConfigurationId'
                 | 'profilingSampleRate'
                 | 'propagateTraceBaggage'
+                | 'trackWebVitals'
             ? never
             : CamelToSnakeCase<Key>
     // By specifying the type here, we can ensure that serializeConfiguration is returning an

packages/rum-core/src/domain/configuration/configuration.ts

@@ -127,6 +127,14 @@ export interface RumInitConfiguration extends InitConfiguration {
    * Allows you to control RUM views creation. See [Override default RUM view names](https://docs.datadoghq.com/real_user_monitoring/browser/advanced_configuration/?tab=npm#override-default-rum-view-names) for further information.
    */
   trackViewsManually?: boolean | undefined
+  /**
+   * Enables collection of Web Vitals / initial view metrics (FCP, LCP, FID, loading time) on the
+   * initial load view. Disable it for pages that are loaded in the background or pre-warmed (e.g. a
+   * hidden Electron window) where these metrics would be measured from an irrelevant navigation
+   * start and reported as abnormally large values.
+   * @default true
+   */
+  trackWebVitals?: boolean | undefined
   /**
    * Enables collection of resource events.
    * @default true
@@ -178,6 +186,7 @@ export interface RumConfiguration extends Configuration {
   startSessionReplayRecordingManually: boolean
   trackUserInteractions: boolean
   trackViewsManually: boolean
+  trackWebVitals: boolean
   trackResources: boolean
   trackLongTasks: boolean
   version?: string
@@ -248,6 +257,7 @@ export function validateAndBuildRumConfiguration(
     compressIntakeRequests: !!initConfiguration.compressIntakeRequests,
     trackUserInteractions: !!(initConfiguration.trackUserInteractions ?? true),
     trackViewsManually: !!initConfiguration.trackViewsManually,
+    trackWebVitals: !!(initConfiguration.trackWebVitals ?? true),
     trackResources: !!(initConfiguration.trackResources ?? true),
     trackLongTasks: !!(initConfiguration.trackLongTasks ?? true),
     subdomain: initConfiguration.subdomain,

packages/rum-core/src/domain/view/trackViews.spec.ts

@@ -447,6 +447,21 @@ describe('view metrics', () => {
   })
 
   describe('initial view metrics', () => {
+    it('should not be collected when trackWebVitals is disabled', () => {
+      viewTest.stop()
+      viewTest = setupViewTest({ lifeCycle, partialConfig: { trackWebVitals: false } })
+
+      notifyPerformanceEntries([
+        createPerformanceEntry(RumPerformanceEntryType.PAINT),
+        createPerformanceEntry(RumPerformanceEntryType.NAVIGATION),
+        createPerformanceEntry(RumPerformanceEntryType.LARGEST_CONTENTFUL_PAINT),
+      ])
+      clock.tick(THROTTLE_VIEW_UPDATE_PERIOD)
+
+      const { getViewUpdate, getViewUpdateCount } = viewTest
+      expect(getViewUpdate(getViewUpdateCount() - 1).initialViewMetrics).toEqual({})
+    })
+
     it('updates should be throttled', () => {
       const { getViewUpdateCount, getViewUpdate } = viewTest
       expect(getViewUpdateCount()).toEqual(1)

packages/rum-core/src/domain/view/trackViews.ts

@@ -252,7 +252,7 @@ function newView(
   )
 
   const { stop: stopInitialViewMetricsTracking, initialViewMetrics } =
-    loadingType === ViewLoadingType.INITIAL_LOAD
+    loadingType === ViewLoadingType.INITIAL_LOAD && configuration.trackWebVitals
       ? trackInitialViewMetrics(configuration, setLoadEvent, scheduleViewUpdate)
       : { stop: noop, initialViewMetrics: {} as InitialViewMetrics }