APM Storybook fixes

* Resolve core legacy assets in @kbn/storybook webpack configuration
* Ignore stories in Jest coverage
* Combine effects in Cytoscape component so handlers are always added before events are triggered
* Add mock context to ErrorRateAlertTrigger stories
* Disable TransactionDurationAlertTrigger stories

Changing the Cytoscape effect behavior is necessary because the layout was not being triggered when the final set of elements is provided as props to the component. When this is used in Kibana we're always starting with empty elements and fetching them, but in the Storybook we're starting out with the full elements.

packages/kbn-storybook/storybook_config/webpack.config.js

@@ -17,7 +17,7 @@
  * under the License.
  */
 
-const { resolve } = require('path');
+const { parse, resolve } = require('path');
 const webpack = require('webpack');
 const { stringifyRequest } = require('loader-utils');
 const CopyWebpackPlugin = require('copy-webpack-plugin');
@@ -95,6 +95,27 @@ module.exports = async ({ config }) => {
           },
         },
       },
+      {
+        loader: 'resolve-url-loader',
+        options: {
+          // If you don't have arguments (_, __) to the join function, the
+          // resolve-url-loader fails with a loader misconfiguration error.
+          //
+          // eslint-disable-next-line no-unused-vars
+          join: (_, __) => (uri, base) => {
+            if (!base || !parse(base).dir.includes('legacy')) {
+              return null;
+            }
+
+            // URIs on mixins in src/legacy/public/styles need to be resolved.
+            if (uri.startsWith('ui/assets')) {
+              return resolve(REPO_ROOT, 'src/core/server/core_app/', uri.replace('ui/', ''));
+            }
+
+            return null;
+          },
+        },
+      },
       {
         loader: 'sass-loader',
         options: {

x-pack/plugins/apm/jest.config.js

@@ -31,6 +31,7 @@ module.exports = {
   collectCoverageFrom: [
     '**/*.{js,jsx,ts,tsx}',
     '!**/{__test__,__snapshots__,__examples__,integration_tests,tests}/**',
+    '!**/*.stories.{js,ts,tsx}',
     '!**/*.test.{js,ts,tsx}',
     '!**/dev_docs/**',
     '!**/e2e/**',

x-pack/plugins/apm/public/components/app/ServiceMap/Cytoscape.stories.tsx

@@ -346,7 +346,7 @@ storiesOf('app/ServiceMap/Cytoscape', module).add(
         },
       },
     ];
-    return <Cytoscape elements={elements} height={300} width={1340} />;
+    return <Cytoscape elements={elements} height={600} width={1340} />;
   },
   {
     info: { propTables: false, source: false },

x-pack/plugins/apm/public/components/app/ServiceMap/Cytoscape.tsx

@@ -121,15 +121,6 @@ export function Cytoscape({
 
   const trackApmEvent = useUiTracker({ app: 'apm' });
 
-  // Trigger a custom "data" event when data changes
-  useEffect(() => {
-    if (cy) {
-      cy.remove(cy.elements());
-      cy.add(elements);
-      cy.trigger('data');
-    }
-  }, [cy, elements]);
-
   // Set up cytoscape event handlers
   useEffect(() => {
     const resetConnectedEdgeStyle = (node?: cytoscape.NodeSingular) => {
@@ -223,6 +214,10 @@ export function Cytoscape({
       cy.on('mouseout', 'edge, node', mouseoutHandler);
       cy.on('select', 'node', selectHandler);
       cy.on('unselect', 'node', unselectHandler);
+
+      cy.remove(cy.elements());
+      cy.add(elements);
+      cy.trigger('data');
     }
 
     return () => {
@@ -241,7 +236,7 @@ export function Cytoscape({
       }
       clearTimeout(layoutstopDelayTimeout);
     };
-  }, [cy, height, serviceName, trackApmEvent, width]);
+  }, [cy, elements, height, serviceName, trackApmEvent, width]);
 
   return (
     <CytoscapeContext.Provider value={cy}>

x-pack/plugins/apm/public/components/shared/ErrorRateAlertTrigger/index.stories.tsx

@@ -7,6 +7,11 @@
 import { storiesOf } from '@storybook/react';
 import React from 'react';
 import { ErrorRateAlertTrigger } from '.';
+import { ApmPluginContextValue } from '../../../context/ApmPluginContext';
+import {
+  mockApmPluginContextValue,
+  MockApmPluginContextWrapper,
+} from '../../../context/ApmPluginContext/MockApmPluginContext';
 
 storiesOf('app/ErrorRateAlertTrigger', module).add('example', () => {
   const params = {
@@ -15,12 +20,16 @@ storiesOf('app/ErrorRateAlertTrigger', module).add('example', () => {
   };
 
   return (
-    <div style={{ width: 400 }}>
-      <ErrorRateAlertTrigger
-        alertParams={params as any}
-        setAlertParams={() => undefined}
-        setAlertProperty={() => undefined}
-      />
-    </div>
+    <MockApmPluginContextWrapper
+      value={(mockApmPluginContextValue as unknown) as ApmPluginContextValue}
+    >
+      <div style={{ width: 400 }}>
+        <ErrorRateAlertTrigger
+          alertParams={params as any}
+          setAlertParams={() => undefined}
+          setAlertProperty={() => undefined}
+        />
+      </div>
+    </MockApmPluginContextWrapper>
   );
 });

x-pack/plugins/apm/public/components/shared/TransactionDurationAlertTrigger/index.stories.tsx

@@ -3,18 +3,24 @@
  * or more contributor license agreements. Licensed under the Elastic License;
  * you may not use this file except in compliance with the Elastic License.
  */
+// import { storiesOf } from '@storybook/react';
 import { cloneDeep, merge } from 'lodash';
-import { storiesOf } from '@storybook/react';
 import React from 'react';
 import { TransactionDurationAlertTrigger } from '.';
+import { ApmPluginContextValue } from '../../../context/ApmPluginContext';
 import {
-  MockApmPluginContextWrapper,
   mockApmPluginContextValue,
+  MockApmPluginContextWrapper,
 } from '../../../context/ApmPluginContext/MockApmPluginContext';
 import { MockUrlParamsContextProvider } from '../../../context/UrlParamsContext/MockUrlParamsContextProvider';
-import { ApmPluginContextValue } from '../../../context/ApmPluginContext';
 
-storiesOf('app/TransactionDurationAlertTrigger', module).add('example', () => {
+// Disabling this because we currently don't have a way to mock `useEnvironments`
+// which is used by this component. Using the fetch-mock module should work, but
+// our current storybook setup has core-js-related problems when trying to import
+// it.
+// storiesOf('app/TransactionDurationAlertTrigger', module).add('example',
+// eslint-disable-next-line no-unused-expressions
+() => {
   const params = {
     threshold: 1500,
     aggregationType: 'avg' as const,
@@ -44,4 +50,4 @@ storiesOf('app/TransactionDurationAlertTrigger', module).add('example', () => {
       </MockApmPluginContextWrapper>
     </div>
   );
-});
+};