[Discover] Fix Elasticsearch query rule for "KQL or Lucene" query wit…

…hout filters (elastic#151632)

Closes elastic#151609 

For testing:
- Go to Rule Management page
- Create a new Rule with "Elasticsearch query" type in "KQL or Lucene"
format
- Save and check the status after the rule finishes the creating process
=> It should say "Succeeded"

x-pack/plugins/stack_alerts/server/rule_types/es_query/lib/fetch_search_source_query.ts

@@ -188,7 +188,7 @@ async function generateLink(
 }
 
 function updateFilterReferences(filters: Filter[], fromDataView: string, toDataView: string) {
-  return filters.map((filter) => {
+  return (filters || []).map((filter) => {
     if (filter.meta.index === fromDataView) {
       return {
         ...filter,

x-pack/test/functional_with_es_ssl/apps/discover_ml_uptime/discover/search_source_alert.ts

@@ -32,6 +32,7 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
   const filterBar = getService('filterBar');
   const find = getService('find');
   const toasts = getService('toasts');
+  const kibanaServer = getService('kibanaServer');
 
   const SOURCE_DATA_VIEW = 'search-source-alert';
   const OUTPUT_DATA_VIEW = 'search-source-alert-output';
@@ -330,6 +331,7 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
       await deleteDataView(outputDataViewId);
       await deleteConnector(connectorId);
       await security.testUser.restoreDefaults();
+      await kibanaServer.savedObjects.cleanStandardList();
     });
 
     it('should create an alert when there is no data view', async () => {
@@ -535,5 +537,60 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
       await checkInitialRuleParamsState(SOURCE_DATA_VIEW);
       await checkInitialDataViewState(SOURCE_DATA_VIEW);
     });
+
+    it('should check that there are no errors detected after an alert is created', async () => {
+      const newAlert = 'New Alert for checking its status';
+      await createDataView('search-source*');
+
+      await PageObjects.common.navigateToApp('management');
+      await PageObjects.header.waitUntilLoadingHasFinished();
+
+      await testSubjects.click('triggersActions');
+      await PageObjects.header.waitUntilLoadingHasFinished();
+
+      await testSubjects.click('createRuleButton');
+      await PageObjects.header.waitUntilLoadingHasFinished();
+
+      await retry.waitFor('rule name value is correct', async () => {
+        await testSubjects.setValue('ruleNameInput', newAlert);
+        const ruleName = await testSubjects.getAttribute('ruleNameInput', 'value');
+        return ruleName === newAlert;
+      });
+
+      await testSubjects.click('.es-query-SelectOption');
+      await PageObjects.header.waitUntilLoadingHasFinished();
+      await testSubjects.click('queryFormType_searchSource');
+      await PageObjects.header.waitUntilLoadingHasFinished();
+
+      await testSubjects.click('selectDataViewExpression');
+      await testSubjects.click('indexPattern-switcher--input');
+      if (await testSubjects.exists('clearSearchButton')) {
+        await testSubjects.click('clearSearchButton');
+      }
+      const dataViewsElem = await testSubjects.find('euiSelectableList');
+      const sourceDataViewOption = await dataViewsElem.findByCssSelector(
+        `[title="search-source*"]`
+      );
+      await sourceDataViewOption.click();
+
+      await testSubjects.click('saveRuleButton');
+
+      await retry.waitFor('confirmation modal', async () => {
+        return await testSubjects.exists('confirmModalConfirmButton');
+      });
+
+      await testSubjects.click('confirmModalConfirmButton');
+
+      await PageObjects.header.waitUntilLoadingHasFinished();
+
+      await openAlertRuleInManagement(newAlert);
+
+      await retry.waitFor('success status', async () => {
+        await browser.refresh();
+        await PageObjects.header.waitUntilLoadingHasFinished();
+
+        return await testSubjects.exists('ruleStatus-ok');
+      });
+    });
   });
 }