[Observability] Lazy load shared components (#88802)

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

x-pack/plugins/apm/public/components/app/RumDashboard/UXMetrics/index.tsx

@@ -4,7 +4,7 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-import React, { useContext } from 'react';
+import React, { useContext, useMemo } from 'react';
 import {
   EuiFlexGroup,
   EuiFlexItem,
@@ -17,7 +17,7 @@ import { I18LABELS } from '../translations';
 import { KeyUXMetrics } from './KeyUXMetrics';
 import { useFetcher } from '../../../../hooks/use_fetcher';
 import { useUxQuery } from '../hooks/useUxQuery';
-import { CoreVitals } from '../../../../../../observability/public';
+import { getCoreVitalsComponent } from '../../../../../../observability/public';
 import { CsmSharedContext } from '../CsmSharedContext';
 import { useUrlParams } from '../../../../context/url_params_context/use_url_params';
 import { getPercentileLabel } from './translations';
@@ -48,6 +48,18 @@ export function UXMetrics() {
     sharedData: { totalPageViews },
   } = useContext(CsmSharedContext);
 
+  const CoreVitals = useMemo(
+    () =>
+      getCoreVitalsComponent({
+        data,
+        totalPageViews,
+        loading: status !== 'success',
+        displayTrafficMetric: true,
+      }),
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+    [status]
+  );
+
   return (
     <EuiPanel>
       <EuiFlexGroup justifyContent="spaceBetween" wrap>
@@ -67,12 +79,7 @@ export function UXMetrics() {
       <EuiFlexGroup justifyContent="spaceBetween" wrap>
         <EuiFlexItem grow={1} data-cy={`client-metrics`}>
           <EuiSpacer size="s" />
-          <CoreVitals
-            data={data}
-            totalPageViews={totalPageViews}
-            loading={status !== 'success'}
-            displayTrafficMetric={true}
-          />
+          {CoreVitals}
         </EuiFlexItem>
       </EuiFlexGroup>
     </EuiPanel>

x-pack/plugins/observability/public/components/app/header/index.tsx

@@ -17,7 +17,7 @@ import { i18n } from '@kbn/i18n';
 import React, { ReactNode } from 'react';
 import styled from 'styled-components';
 import { usePluginContext } from '../../../hooks/use_plugin_context';
-import { HeaderMenuPortal } from '../../shared/header_menu_portal';
+import HeaderMenuPortal from '../../shared/header_menu_portal';
 
 const Container = styled.div<{ color: string }>`
   background: ${(props) => props.color};

x-pack/plugins/observability/public/components/app/section/ux/index.tsx

@@ -12,7 +12,7 @@ import { FETCH_STATUS, useFetcher } from '../../../../hooks/use_fetcher';
 import { useHasData } from '../../../../hooks/use_has_data';
 import { useTimeRange } from '../../../../hooks/use_time_range';
 import { UXHasDataResponse } from '../../../../typings';
-import { CoreVitals } from '../../../shared/core_web_vitals';
+import CoreVitals from '../../../shared/core_web_vitals';
 
 interface Props {
   bucketSize: string;

x-pack/plugins/observability/public/components/shared/core_web_vitals/index.tsx

@@ -16,6 +16,7 @@ import {
 import { CoreVitalItem } from './core_vital_item';
 import { WebCoreVitalsTitle } from './web_core_vitals_title';
 import { ServiceName } from './service_name';
+import { CoreVitalProps } from '../types';
 
 export interface UXMetrics {
   cls: number | null;
@@ -29,7 +30,7 @@ export interface UXMetrics {
   clsRanks: number[];
 }
 
-export function formatToSec(value?: number | string, fromUnit = 'MicroSec'): string {
+function formatToSec(value?: number | string, fromUnit = 'MicroSec'): string {
   const valueInMs = Number(value ?? 0) / (fromUnit === 'MicroSec' ? 1000 : 1);
 
   if (valueInMs < 1000) {
@@ -51,23 +52,15 @@ const CoreVitalsThresholds = {
   CLS: { good: '0.1', bad: '0.25' },
 };
 
-interface Props {
-  loading: boolean;
-  data?: UXMetrics | null;
-  displayServiceName?: boolean;
-  serviceName?: string;
-  totalPageViews?: number;
-  displayTrafficMetric?: boolean;
-}
-
-export function CoreVitals({
+// eslint-disable-next-line import/no-default-export
+export default function CoreVitals({
   data,
   loading,
   displayServiceName,
   serviceName,
   totalPageViews,
   displayTrafficMetric = false,
-}: Props) {
+}: CoreVitalProps) {
   const { lcp, lcpRanks, fid, fidRanks, cls, clsRanks, coreVitalPages } = data || {};
 
   return (

x-pack/plugins/observability/public/components/shared/header_menu_portal.tsx

@@ -4,17 +4,13 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-import React, { ReactNode, useEffect, useMemo } from 'react';
+import React, { useEffect, useMemo } from 'react';
 import { createPortalNode, InPortal, OutPortal } from 'react-reverse-portal';
-import { AppMountParameters } from '../../../../../../src/core/public';
 import { toMountPoint } from '../../../../../../src/plugins/kibana_react/public';
+import { HeaderMenuPortalProps } from './types';
 
-interface HeaderMenuPortalProps {
-  children: ReactNode;
-  setHeaderActionMenu: AppMountParameters['setHeaderActionMenu'];
-}
-
-export function HeaderMenuPortal({ children, setHeaderActionMenu }: HeaderMenuPortalProps) {
+// eslint-disable-next-line import/no-default-export
+export default function HeaderMenuPortal({ children, setHeaderActionMenu }: HeaderMenuPortalProps) {
   const portalNode = useMemo(() => createPortalNode(), []);
 
   useEffect(() => {

x-pack/plugins/observability/public/components/shared/index.tsx

@@ -0,0 +1,26 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import React, { lazy, Suspense } from 'react';
+import { CoreVitalProps, HeaderMenuPortalProps } from './types';
+
+export function getCoreVitalsComponent(props: CoreVitalProps) {
+  const CoreVitalsLazy = lazy(() => import('./core_web_vitals/index'));
+  return (
+    <Suspense fallback={null}>
+      <CoreVitalsLazy {...props} />
+    </Suspense>
+  );
+}
+
+export function HeaderMenuPortal(props: HeaderMenuPortalProps) {
+  const HeaderMenuPortalLazy = lazy(() => import('./header_menu_portal'));
+  return (
+    <Suspense fallback={null}>
+      <HeaderMenuPortalLazy {...props} />
+    </Suspense>
+  );
+}

x-pack/plugins/observability/public/components/shared/types.ts

@@ -0,0 +1,23 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import { ReactNode } from 'react';
+import { AppMountParameters } from '../../../../../../src/core/public';
+import { UXMetrics } from './core_web_vitals';
+
+export interface HeaderMenuPortalProps {
+  children: ReactNode;
+  setHeaderActionMenu: AppMountParameters['setHeaderActionMenu'];
+}
+
+export interface CoreVitalProps {
+  loading: boolean;
+  data?: UXMetrics | null;
+  displayServiceName?: boolean;
+  serviceName?: string;
+  totalPageViews?: number;
+  displayTrafficMetric?: boolean;
+}

x-pack/plugins/observability/public/index.ts

@@ -6,8 +6,7 @@
 
 import { PluginInitializerContext, PluginInitializer } from 'kibana/public';
 import { Plugin, ObservabilityPluginSetup, ObservabilityPluginStart } from './plugin';
-export { HeaderMenuPortal } from './components/shared/header_menu_portal';
-export { ObservabilityPluginSetup, ObservabilityPluginStart };
+export type { ObservabilityPluginSetup, ObservabilityPluginStart };
 
 export const plugin: PluginInitializer<ObservabilityPluginSetup, ObservabilityPluginStart> = (
   context: PluginInitializerContext
@@ -17,7 +16,8 @@ export const plugin: PluginInitializer<ObservabilityPluginSetup, ObservabilityPl
 
 export * from './components/shared/action_menu/';
 
-export { UXMetrics, CoreVitals, formatToSec } from './components/shared/core_web_vitals/';
+export type { UXMetrics } from './components/shared/core_web_vitals/';
+export { getCoreVitalsComponent, HeaderMenuPortal } from './components/shared/';
 
 export {
   useTrackPageview,