[APM] Bug fixes from ML integration testing (#71564)

* fixes bug where the anomaly detection setup link was showing alert incorrectly, adds unit tests

* Fixes typo in getMlBucketSize query, uses terminate_after

* Improve readbility of helper function to show alerts and unit tests

x-pack/plugins/apm/public/components/shared/Links/apm/AnomalyDetectionSetupLink.test.tsx

@@ -0,0 +1,43 @@
+/*
+ * 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 { showAlert } from './AnomalyDetectionSetupLink';
+
+describe('#showAlert', () => {
+  describe('when an environment is selected', () => {
+    it('should return true when there are no jobs', () => {
+      const result = showAlert([], 'testing');
+      expect(result).toBe(true);
+    });
+    it('should return true when environment is not included in the jobs', () => {
+      const result = showAlert(
+        [{ environment: 'staging' }, { environment: 'production' }],
+        'testing'
+      );
+      expect(result).toBe(true);
+    });
+    it('should return false when environment is included in the jobs', () => {
+      const result = showAlert(
+        [{ environment: 'staging' }, { environment: 'production' }],
+        'staging'
+      );
+      expect(result).toBe(false);
+    });
+  });
+  describe('there is no environment selected (All)', () => {
+    it('should return true when there are no jobs', () => {
+      const result = showAlert([], undefined);
+      expect(result).toBe(true);
+    });
+    it('should return false when there are any number of jobs', () => {
+      const result = showAlert(
+        [{ environment: 'staging' }, { environment: 'production' }],
+        undefined
+      );
+      expect(result).toBe(false);
+    });
+  });
+});

x-pack/plugins/apm/public/components/shared/Links/apm/AnomalyDetectionSetupLink.tsx

@@ -23,16 +23,12 @@ export function AnomalyDetectionSetupLink() {
   );
   const isFetchSuccess = status === FETCH_STATUS.SUCCESS;
 
-  // Show alert if there are no jobs OR if no job matches the current environment
-  const showAlert =
-    isFetchSuccess && !data.jobs.some((job) => environment === job.environment);
-
   return (
     <APMLink path="/settings/anomaly-detection">
       <EuiButtonEmpty size="s" color="primary" iconType="inspect">
         {ANOMALY_DETECTION_LINK_LABEL}
       </EuiButtonEmpty>
-      {showAlert && (
+      {isFetchSuccess && showAlert(data.jobs, environment) && (
         <EuiToolTip position="bottom" content={getTooltipText(environment)}>
           <EuiIcon type="alert" color="danger" />
         </EuiToolTip>
@@ -61,3 +57,16 @@ const ANOMALY_DETECTION_LINK_LABEL = i18n.translate(
   'xpack.apm.anomalyDetectionSetup.linkLabel',
   { defaultMessage: `Anomaly detection` }
 );
+
+export function showAlert(
+  jobs: Array<{ environment: string }> = [],
+  environment: string | undefined
+) {
+  return (
+    // No job exists, or
+    jobs.length === 0 ||
+    // no job exists for the selected environment
+    (environment !== undefined &&
+      jobs.every((job) => environment !== job.environment))
+  );
+}

x-pack/plugins/apm/server/lib/transactions/charts/get_anomaly_data/get_ml_bucket_size.ts

@@ -31,7 +31,7 @@ export async function getMlBucketSize({
     body: {
       _source: 'bucket_span',
       size: 1,
-      terminateAfter: 1,
+      terminate_after: 1,
       query: {
         bool: {
           filter: [