Do not show alerts tab when alerting is disabled (#25285)

* Do not show alerts tab when alerting is disabled

* Add tests

public/app/features/dashboard/components/PanelEditor/state/selectors.test.ts

+import { getPanelEditorTabs } from './selectors';
+import { LocationState } from 'app/types';
+import { PanelPlugin } from '@grafana/data';
+import { PanelEditorTabId } from '../types';
+import { updateConfig } from '../../../../../core/config';
+
+describe('getPanelEditorTabs selector', () => {
+  it('return no tabs when no plugin provided', () => {
+    expect(getPanelEditorTabs({} as LocationState)).toEqual([]);
+  });
+
+  it('return no tabs when plugin do not support queries', () => {
+    expect(getPanelEditorTabs({} as LocationState, { meta: { skipDataQuery: true } } as PanelPlugin)).toEqual([]);
+  });
+
+  describe('alerts tab', () => {
+    describe('when alerting enabled', () => {
+      beforeAll(() => {
+        updateConfig({
+          alertingEnabled: true,
+        });
+      });
+
+      it('returns Alerts tab for graph panel', () => {
+        const tabs = getPanelEditorTabs(
+          { query: {} } as LocationState,
+          {
+            meta: {
+              id: 'graph',
+            },
+          } as PanelPlugin
+        );
+
+        expect(tabs.length).toEqual(3);
+        expect(tabs[2].id).toEqual(PanelEditorTabId.Alert);
+      });
+
+      it('does not returns tab for panel other than graph', () => {
+        const tabs = getPanelEditorTabs(
+          { query: {} } as LocationState,
+          {
+            meta: {
+              id: 'table',
+            },
+          } as PanelPlugin
+        );
+        expect(tabs.length).toEqual(2);
+        expect(tabs[1].id).toEqual(PanelEditorTabId.Transform);
+      });
+    });
+
+    describe('when alerting disabled', () => {
+      beforeAll(() => {
+        updateConfig({
+          alertingEnabled: false,
+        });
+      });
+
+      it('does not return Alerts tab', () => {
+        const tabs = getPanelEditorTabs(
+          { query: {} } as LocationState,
+          {
+            meta: {
+              id: 'graph',
+            },
+          } as PanelPlugin
+        );
+
+        expect(tabs.length).toEqual(2);
+        expect(tabs[1].id).toEqual(PanelEditorTabId.Transform);
+      });
+    });
+  });
+});

public/app/features/dashboard/components/PanelEditor/state/selectors.ts

@@ -2,6 +2,7 @@ import memoizeOne from 'memoize-one';
 import { LocationState } from 'app/types';
 import { PanelPlugin } from '@grafana/data';
 import { PanelEditorTab, PanelEditorTabId } from '../types';
+import { getConfig } from 'app/core/config';
 
 export const getPanelEditorTabs = memoizeOne((location: LocationState, plugin?: PanelPlugin) => {
   const tabs: PanelEditorTab[] = [];
@@ -34,7 +35,7 @@ export const getPanelEditorTabs = memoizeOne((location: LocationState, plugin?:
     });
   }
 
-  if (plugin.meta.id === 'graph') {
+  if (getConfig().alertingEnabled && plugin.meta.id === 'graph') {
     tabs.push({
       id: PanelEditorTabId.Alert,
       text: 'Alert',