[Alerting] change index action config executionTimeField to nullable (#61127)

resolves https://github.com/elastic/kibana/issues/61056

When the index action params moved into config, the `schema.maybe()` on the
`executionTimeField` should have been changed to `schema.nullable()`, otherwise
you can never "unset" the field, once it's set.

Changes rippled down to the UI as well.

To be extra safe, we also check that the `executionTimeField` isn't an empty
string when trimmed, as ES will not accept a document with a property that is
the empty string.

x-pack/plugins/actions/server/builtin_action_types/es_index.test.ts

@@ -52,6 +52,7 @@ describe('config validation', () => {
       ...config,
       index: 'testing-123',
       refresh: false,
+      executionTimeField: null,
     });
 
     config.executionTimeField = 'field-123';
@@ -62,6 +63,14 @@ describe('config validation', () => {
       executionTimeField: 'field-123',
     });
 
+    config.executionTimeField = null;
+    expect(validateConfig(actionType, config)).toEqual({
+      ...config,
+      index: 'testing-123',
+      refresh: false,
+      executionTimeField: null,
+    });
+
     delete config.index;
 
     expect(() => {
@@ -73,9 +82,11 @@ describe('config validation', () => {
 
     expect(() => {
       validateConfig(actionType, { index: 'testing-123', executionTimeField: true });
-    }).toThrowErrorMatchingInlineSnapshot(
-      `"error validating action type config: [executionTimeField]: expected value of type [string] but got [boolean]"`
-    );
+    }).toThrowErrorMatchingInlineSnapshot(`
+"error validating action type config: [executionTimeField]: types that failed validation:
+- [executionTimeField.0]: expected value of type [string] but got [boolean]
+- [executionTimeField.1]: expected value to equal [null]"
+`);
 
     delete config.refresh;
     expect(() => {
@@ -138,12 +149,12 @@ describe('params validation', () => {
 describe('execute()', () => {
   test('ensure parameters are as expected', async () => {
     const secrets = {};
-    let config: ActionTypeConfigType;
+    let config: Partial<ActionTypeConfigType>;
     let params: ActionParamsType;
     let executorOptions: ActionTypeExecutorOptions;
 
     // minimal params
-    config = { index: 'index-value', refresh: false, executionTimeField: undefined };
+    config = { index: 'index-value', refresh: false };
     params = {
       documents: [{ jim: 'bob' }],
     };

x-pack/plugins/actions/server/builtin_action_types/es_index.ts

@@ -18,7 +18,7 @@ export type ActionTypeConfigType = TypeOf<typeof ConfigSchema>;
 const ConfigSchema = schema.object({
   index: schema.string(),
   refresh: schema.boolean({ defaultValue: false }),
-  executionTimeField: schema.maybe(schema.string()),
+  executionTimeField: schema.nullable(schema.string()),
 });
 
 // params definition
@@ -63,8 +63,9 @@ async function executor(
 
   const bulkBody = [];
   for (const document of params.documents) {
-    if (config.executionTimeField != null) {
-      document[config.executionTimeField] = new Date();
+    const timeField = config.executionTimeField == null ? '' : config.executionTimeField.trim();
+    if (timeField !== '') {
+      document[timeField] = new Date();
     }
 
     bulkBody.push({ index: {} });

x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/es_index.test.tsx

@@ -52,6 +52,26 @@ describe('index connector validation', () => {
   });
 });
 
+describe('index connector validation with minimal config', () => {
+  test('connector validation succeeds when connector config is valid', () => {
+    const actionConnector = {
+      secrets: {},
+      id: 'test',
+      actionTypeId: '.index',
+      name: 'es_index',
+      config: {
+        index: 'test_es_index',
+      },
+    } as EsIndexActionConnector;
+
+    expect(actionTypeModel.validateConnector(actionConnector)).toEqual({
+      errors: {
+        index: [],
+      },
+    });
+  });
+});
+
 describe('action params validation', () => {
   test('action params validation succeeds when action params is valid', () => {
     const actionParams = {

x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/es_index.tsx

@@ -79,7 +79,7 @@ const IndexActionConnectorFields: React.FunctionComponent<ActionConnectorFieldsP
 >> = ({ action, editActionConfig, errors, http }) => {
   const { index, refresh, executionTimeField } = action.config;
   const [hasTimeFieldCheckbox, setTimeFieldCheckboxState] = useState<boolean>(
-    executionTimeField !== undefined
+    executionTimeField != null
   );
 
   const [indexPatterns, setIndexPatterns] = useState([]);
@@ -206,6 +206,11 @@ const IndexActionConnectorFields: React.FunctionComponent<ActionConnectorFieldsP
         checked={hasTimeFieldCheckbox || false}
         onChange={() => {
           setTimeFieldCheckboxState(!hasTimeFieldCheckbox);
+          // if changing from checked to not checked (hasTimeField === true),
+          // set time field to null
+          if (hasTimeFieldCheckbox) {
+            editActionConfig('executionTimeField', null);
+          }
         }}
         label={
           <>
@@ -245,13 +250,13 @@ const IndexActionConnectorFields: React.FunctionComponent<ActionConnectorFieldsP
               fullWidth
               name="executionTimeField"
               data-test-subj="executionTimeFieldSelect"
-              value={executionTimeField}
+              value={executionTimeField ?? ''}
               onChange={e => {
-                editActionConfig('executionTimeField', e.target.value);
+                editActionConfig('executionTimeField', nullableString(e.target.value));
               }}
               onBlur={() => {
                 if (executionTimeField === undefined) {
-                  editActionConfig('executionTimeField', '');
+                  editActionConfig('executionTimeField', null);
                 }
               }}
             />
@@ -312,3 +317,9 @@ const IndexParamsFields: React.FunctionComponent<ActionParamsProps<IndexActionPa
     </Fragment>
   );
 };
+
+// if the string == null or is empty, return null, else return string
+function nullableString(str: string | null | undefined) {
+  if (str == null || str.trim() === '') return null;
+  return str;
+}

x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/types.ts

@@ -83,7 +83,7 @@ export interface EmailActionConnector extends ActionConnector {
 
 interface EsIndexConfig {
   index: string;
-  executionTimeField?: string;
+  executionTimeField?: string | null;
   refresh?: boolean;
 }
 

x-pack/test/alerting_api_integration/security_and_spaces/tests/actions/builtin_action_types/es_index.ts

@@ -45,6 +45,7 @@ export default function indexTest({ getService }: FtrProviderContext) {
         config: {
           index: ES_TEST_INDEX_NAME,
           refresh: false,
+          executionTimeField: null,
         },
       });
       createdActionID = createdAction.id;
@@ -58,7 +59,7 @@ export default function indexTest({ getService }: FtrProviderContext) {
         id: fetchedAction.id,
         name: 'An index action',
         actionTypeId: '.index',
-        config: { index: ES_TEST_INDEX_NAME, refresh: false },
+        config: { index: ES_TEST_INDEX_NAME, refresh: false, executionTimeField: null },
       });
 
       // create action with all config props

x-pack/test/alerting_api_integration/spaces_only/tests/actions/builtin_action_types/es_index.ts

@@ -43,6 +43,7 @@ export default function indexTest({ getService }: FtrProviderContext) {
         config: {
           index: ES_TEST_INDEX_NAME,
           refresh: false,
+          executionTimeField: null,
         },
       });
       createdActionID = createdAction.id;
@@ -56,7 +57,7 @@ export default function indexTest({ getService }: FtrProviderContext) {
         id: fetchedAction.id,
         name: 'An index action',
         actionTypeId: '.index',
-        config: { index: ES_TEST_INDEX_NAME, refresh: false },
+        config: { index: ES_TEST_INDEX_NAME, refresh: false, executionTimeField: null },
       });
 
       // create action with all config props