[ML] Fix Anomaly charts embeddable fails to load if partition value i…

…s empty string (elastic#167827)

## Summary

Fix elastic#165847. This PR fixes
Anomaly charts embeddable failing to load if partition value is an empty
string. This bug is caused by invalid kuery string when a field value is
empty.

Previously, embeddable input was receiving the following kql query
`{exampleFieldName}:` if the value is empty. The fix in this PR makes it
so it's `{exampleFieldName}:""`. So a new function
getEscapedKueryForSelectionInfluencer is added for this specific
scenario.

Making a new function here instead of updating
`escapeKueryForFieldValuePair` because all the other usages of that
function are related to opening a URL so it requires a special escape.

### After:


https://github.com/elastic/kibana/assets/43350163/f09b207f-1c4c-42a5-aaea-dad50512676c




### Steps to reproduce:

- In a data view, create a new runtime field. For this runtime field,
set to `keyword` type, and use following script to mimic having an empty
field for certain docs.
```
def source = doc['ampersand&name'].value;
if (source == "AWE") {
	emit("");
}
else {
	emit(doc['ampersand&name'].value);
}
```
- Create an Anomaly detection using that data view, using the runtime
field as a split field or partition field.

### Checklist

Delete any items that are not applicable to this PR.

- [ ] Any text added follows [EUI's writing
guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses
sentence case text and includes [i18n
support](https://github.com/elastic/kibana/blob/main/packages/kbn-i18n/README.md)
- [ ]
[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials
- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [ ] Any UI touched in this PR is usable by keyboard only (learn more
about [keyboard accessibility](https://webaim.org/techniques/keyboard/))
- [ ] Any UI touched in this PR does not create any new axe failures
(run axe in browser:
[FF](https://addons.mozilla.org/en-US/firefox/addon/axe-devtools/),
[Chrome](https://chrome.google.com/webstore/detail/axe-web-accessibility-tes/lhdoppojpmngadmnindnejefpokejbdd?hl=en-US))
- [ ] If a plugin configuration key changed, check if it needs to be
allowlisted in the cloud and added to the [docker
list](https://github.com/elastic/kibana/blob/main/src/dev/build/tasks/os_packages/docker_generator/resources/base/bin/kibana-docker)
- [ ] This renders correctly on smaller devices using a responsive
layout. (You can test this [in your
browser](https://www.browserstack.com/guide/responsive-testing-on-local-server))
- [ ] This was checked for [cross-browser
compatibility](https://www.elastic.co/support/matrix#matrix_browsers)


### Risk Matrix

Delete this section if it is not applicable to this PR.

Before closing this PR, invite QA, stakeholders, and other developers to
identify risks that should be tested prior to the change/feature
release.

When forming the risk matrix, consider some of the following examples
and how they may potentially impact the change:

| Risk | Probability | Severity | Mitigation/Notes |

|---------------------------|-------------|----------|-------------------------|
| Multiple Spaces—unexpected behavior in non-default Kibana Space.
| Low | High | Integration tests will verify that all features are still
supported in non-default Kibana Space and when user switches between
spaces. |
| Multiple nodes—Elasticsearch polling might have race conditions
when multiple Kibana nodes are polling for the same tasks. | High | Low
| Tasks are idempotent, so executing them multiple times will not result
in logical error, but will degrade performance. To test for this case we
add plenty of unit tests around this logic and document manual testing
procedure. |
| Code should gracefully handle cases when feature X or plugin Y are
disabled. | Medium | High | Unit tests will verify that any feature flag
or plugin combination still results in our service operational. |
| [See more potential risk
examples](https://github.com/elastic/kibana/blob/main/RISK_MATRIX.mdx) |


### For maintainers

- [ ] This was checked for breaking API changes and was [labeled
appropriately](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

---------

Co-authored-by: Kibana Machine <[email protected]>

x-pack/plugins/ml/public/application/explorer/anomaly_context_menu.tsx

@@ -40,7 +40,7 @@ import { JobId } from '../../../common/types/anomaly_detection_jobs';
 import { getDefaultExplorerChartsPanelTitle } from '../../embeddables/anomaly_charts/anomaly_charts_embeddable';
 import { MAX_ANOMALY_CHARTS_ALLOWED } from '../../embeddables/anomaly_charts/anomaly_charts_initializer';
 import { useAnomalyExplorerContext } from './anomaly_explorer_context';
-import { escapeKueryForFieldValuePair } from '../util/string_utils';
+import { escapeKueryForEmbeddableFieldValuePair } from '../util/string_utils';
 import { useCasesModal } from '../contexts/kibana/use_cases_modal';
 import { DEFAULT_MAX_SERIES_TO_PLOT } from '../services/anomaly_explorer_charts_service';
 import {
@@ -154,7 +154,7 @@ export const AnomalyContextMenu: FC<AnomalyContextMenuProps> = ({
       const influencers = selectionInfluencers ?? [];
       const config = getDefaultEmbeddablePanelConfig(jobIds, queryString);
       const queryFromSelectedCells = influencers
-        .map((s) => escapeKueryForFieldValuePair(s.fieldName, s.fieldValue))
+        .map((s) => escapeKueryForEmbeddableFieldValuePair(s.fieldName, s.fieldValue))
         .join(' or ');
 
       // When adding anomaly charts to Dashboard, we want to respect the Dashboard's time range

x-pack/plugins/ml/public/application/util/string_utils.test.ts

@@ -14,6 +14,7 @@ import {
   toLocaleString,
   mlEscape,
   escapeForElasticsearchQuery,
+  escapeKueryForEmbeddableFieldValuePair,
 } from './string_utils';
 
 describe('ML - string utils', () => {
@@ -160,4 +161,13 @@ describe('ML - string utils', () => {
       expect(escapeForElasticsearchQuery('foo/bar')).toBe('foo\\/bar');
     });
   });
+  describe('escapeKueryForEmbeddableFieldValuePair', () => {
+    test('should return correct escaping of kuery values', () => {
+      expect(escapeKueryForEmbeddableFieldValuePair('fieldName', '')).toBe('fieldName:""');
+      expect(escapeKueryForEmbeddableFieldValuePair('', 'fieldValue')).toBe('"":fieldValue');
+      expect(escapeKueryForEmbeddableFieldValuePair('@#specialCharsName%', '<>:;[})')).toBe(
+        '@#specialCharsName%:\\<\\>\\:;[}\\)'
+      );
+    });
+  });
 });

x-pack/plugins/ml/public/application/util/string_utils.ts

@@ -140,6 +140,26 @@ export function escapeKueryForFieldValuePair(
   return `${escapeKuery(name)}:${escapeKuery(value.toString())}`;
 }
 
+const replaceEmptyStringWithQuotation = (s: string) => (s === '' ? '""' : s);
+
+/**
+ *
+ * Helper function to returns escaped combined field name and value
+ * which also replaces empty str with " to ensure compatability with kql queries
+ * @param name fieldName of selection
+ * @param value fieldValue of selection
+ * @returns {string} escaped `name:value` compatible with embeddable input
+ */
+export function escapeKueryForEmbeddableFieldValuePair(
+  name: string,
+  value: string | number | boolean | undefined
+): string {
+  if (!isDefined(name) || !isDefined(value)) return '';
+  return `${replaceEmptyStringWithQuotation(escapeKuery(name))}:${replaceEmptyStringWithQuotation(
+    escapeKuery(value.toString())
+  )}`;
+}
+
 export function calculateTextWidth(txt: string | number, isNumber: boolean) {
   txt = isNumber && typeof txt === 'number' ? d3.format(',')(txt) : txt;