[ML] Fix check for watcher being enabled (#43025) (#43036)

* [ML] Fix check for watcher being enabled

* adding comments

* typo

* fixing test

x-pack/legacy/plugins/ml/public/license/__tests__/check_license.js

@@ -6,20 +6,21 @@
 
 import expect from '@kbn/expect';
 import { xpackInfo } from '../../../../xpack_main/public/services/xpack_info';
+import { LICENSE_STATUS_VALID } from '../../../../../common/constants/license_status';
 import {
   xpackFeatureAvailable,
 } from '../check_license';
 
 const initialInfo = {
   features: {
     watcher: {
-      isAvailable: true
+      status: LICENSE_STATUS_VALID
     }
   }
 };
 
 describe('ML - check license', () => {
-  describe('xpackFeatureProvider', () => {
+  describe('xpackFeatureAvailable', () => {
     beforeEach(() => {
       xpackInfo.setAll(initialInfo);
     });

x-pack/legacy/plugins/ml/public/license/check_license.js

@@ -9,6 +9,7 @@ import React from 'react';
 import { xpackInfo } from '../../../xpack_main/public/services/xpack_info';
 import { banners, addAppRedirectMessageToUrl } from 'ui/notify';
 import { LICENSE_TYPE } from '../../common/constants/license';
+import { LICENSE_STATUS_VALID } from '../../../../common/constants/license_status';
 
 import chrome from 'ui/chrome';
 import { EuiCallOut } from '@elastic/eui';
@@ -119,5 +120,17 @@ export function isFullLicense() {
 }
 
 export function xpackFeatureAvailable(feature) {
-  return xpackInfo.get(`features.${feature}.isAvailable`, false);
+  // each plugin can register their own set of features.
+  // so we need specific checks for each one.
+  // this list can grow if we need to check other plugin's features.
+  switch (feature) {
+    case 'watcher':
+      // watcher only has a license status feature
+      // if watcher is disabled in kibana.yml, the feature is completely missing from xpackInfo
+      return xpackInfo.get(`features.${feature}.status`, false) === LICENSE_STATUS_VALID;
+    default:
+      // historically plugins have used `isAvailable` as a catch all for
+      // license and feature enabled checks
+      return xpackInfo.get(`features.${feature}.isAvailable`, false);
+  }
 }