[ML][Discover] Add change point view in Discover (elastic#265331)

## Summary

This PR adds a change point view in Discover. 

~~Closes elastic#232587 - moved to
dedicated PR elastic#269572


https://github.com/user-attachments/assets/140673d7-cb98-43d4-b406-82965ad53363

<img width="1470" height="888" alt="image"
src="https://github.com/user-attachments/assets/813293d6-edd2-43ab-9e50-7eb753faa9ab"
/>


### Dependencies

~~This PR is blocked by
[this](elastic/elasticsearch#145210) work which
will add the BY functionality. I tested this by checking out that branch
and running ES locally.~~
PR has been merged. 

Changes to `kbn-lens-embeddable-utils` package have been moved to a
dedicated PR in elastic#269824 -- This PR
needs to go in before this one.

### Notes for testing

Example ES|QL commands using sample data (Note you may need to play
around with the bucket length or the function - sum, count, avg, etc).

For many change points:

```
FROM kibana_sample_data_logs
| STATS avg_bytes=AVG(bytes) BY geo.dest, day=BUCKET(timestamp, 1d)
| CHANGE_POINT avg_bytes ON day BY geo.dest
| WHERE type IS NOT NULL
```

Multiple groupings:

```
FROM kibana_sample_data_logs
| STATS sum_bytes=SUM(bytes) BY host, response.keyword, day=BUCKET(timestamp, 1 d)
| CHANGE_POINT sum_bytes ON day BY host, response.keyword
 | WHERE type IS NOT NULL
```

No groupings:

```
FROM kibana_sample_data_logs
| STATS avg_bytes=AVG(bytes) BY day=BUCKET(timestamp, 1d)
| CHANGE_POINT avg_bytes ON day
| WHERE type IS NOT NULL
```

Using TS also:

```
TS kibana_sample_data_logstsdb | STATS avg_bytes=AVG(bytes) BY geo.dest, day=BUCKET(@timestamp, 4h)
| CHANGE_POINT avg_bytes ON day BY geo.dest
| WHERE type IS NOT NULL
```

### Checklist

Check the PR satisfies following conditions. 

Reviewers should verify this PR satisfies this list as well.

- [ ] 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/src/platform/packages/shared/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
- [ ] [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
- [ ] 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 was checked for breaking HTTP API changes, and any breaking
changes have been approved by the breaking-change committee. The
`release_note:breaking` label should be applied in these situations.
- [ ] [Flaky Test
Runner](https://ci-stats.kibana.dev/trigger_flaky_test_runner/1) was
used on any tests changed
- [ ] The PR description includes the appropriate Release Notes section,
and the correct `release_note:*` label is applied per the
[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)
- [ ] Review the [backport
guidelines](https://docs.google.com/document/d/1VyN5k91e5OVumlc0Gb9RPa3h1ewuPE705nRtioPiTvY/edit?usp=sharing)
and apply applicable `backport:*` labels.

### Identify risks

Does this PR introduce any risks? For example, consider risks like hard
to test bugs, performance regression, potential of data loss.

Describe the risk, its severity, and mitigation for each identified
risk. Invite stakeholders and evaluate how to proceed before merging.

- [ ] [See some risk
examples](https://github.com/elastic/kibana/blob/main/RISK_MATRIX.mdx)
- [ ] ...

---------

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>
Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>
Co-authored-by: Stratou <efstratia.kalafateli@elastic.co>

Author: 4 people

.github/CODEOWNERS

@@ -519,6 +519,7 @@ src/platform/packages/shared/kbn-calculate-width-from-char-count @elastic/kibana
 src/platform/packages/shared/kbn-cases-components @elastic/kibana-cases
 src/platform/packages/shared/kbn-cbor @elastic/kibana-operations
 src/platform/packages/shared/kbn-cell-actions @elastic/security-threat-hunting
+src/platform/packages/shared/kbn-change-point-chart-viewer @elastic/ml-ui
 src/platform/packages/shared/kbn-chart-icons @elastic/kibana-visualizations
 src/platform/packages/shared/kbn-charts-theme @elastic/kibana-visualizations
 src/platform/packages/shared/kbn-cleanup-before-exit @elastic/observability-ui
@@ -1541,6 +1542,7 @@ x-pack/platform/test/serverless/api_integration/test_suites/platform_security @e
 /src/platform/plugins/shared/discover/public/context_awareness/profile_providers/common/metrics_data_source_profile @elastic/obs-exploration-team
 /src/platform/plugins/shared/discover/public/context_awareness/profile_providers/common/deprecation_logs_data_source_profile @elastic/kibana-data-discovery @elastic/kibana-core
 /src/platform/plugins/shared/discover/public/context_awareness/profile_providers/common/patterns_data_source_profile @elastic/ml-ui
+/src/platform/plugins/shared/discover/public/context_awareness/profile_providers/common/change_point_data_source_profile @elastic/ml-ui
 /src/platform/plugins/shared/discover/public/context_awareness/profile_providers/observability @elastic/kibana-data-discovery @elastic/obs-exploration-team
 /src/platform/plugins/shared/discover/public/context_awareness/profile_providers/observability/observability_document_profile @elastic/obs-exploration-team
 /src/platform/plugins/shared/discover/public/context_awareness/profile_providers/observability/observability_root_profile @elastic/obs-exploration-team

.i18nrc.json

@@ -97,6 +97,7 @@
       "src/platform/packages/shared/kbn-management",
       "packages/kbn-management"
     ],
+    "changePointChartViewer": "src/platform/packages/shared/kbn-change-point-chart-viewer/src",
     "metricsExperience": "src/platform/packages/shared/kbn-unified-chart-section-viewer/src",
     "monaco": "src/platform/packages/shared/kbn-monaco/src",
     "navigation": [

package.json

@@ -277,6 +277,7 @@
     "@kbn/cbor": "link:src/platform/packages/shared/kbn-cbor",
     "@kbn/cell-actions": "link:src/platform/packages/shared/kbn-cell-actions",
     "@kbn/change-history": "link:x-pack/platform/packages/shared/kbn-change-history",
+    "@kbn/change-point-chart-viewer": "link:src/platform/packages/shared/kbn-change-point-chart-viewer",
     "@kbn/chart-expressions-common": "link:src/platform/packages/shared/chart-expressions-common",
     "@kbn/chart-icons": "link:src/platform/packages/shared/kbn-chart-icons",
     "@kbn/charts-plugin": "link:src/platform/plugins/shared/charts",

src/platform/packages/shared/kbn-change-point-chart-viewer/index.ts

@@ -0,0 +1,17 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+export { LazyChangePointExperienceGrid } from './src/lazy_change_point_experience_grid';
+export type { ChangePointChartSectionActions, UnifiedChangePointGridProps } from './src/types';
+export {
+  getPvalueImpactLevel,
+  PVALUE_IMPACT_COLORS,
+  PVALUE_IMPACT_LEVELS,
+} from './src/utils/get_pvalue_impact';
+export type { PvalueImpactLevel } from './src/utils/get_pvalue_impact';

src/platform/packages/shared/kbn-change-point-chart-viewer/jest.config.js

@@ -0,0 +1,14 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+module.exports = {
+  preset: '@kbn/test',
+  rootDir: '../../../../..',
+  roots: ['<rootDir>/src/platform/packages/shared/kbn-change-point-chart-viewer'],
+};

src/platform/packages/shared/kbn-change-point-chart-viewer/kibana.jsonc

@@ -0,0 +1,7 @@
+{
+  "type": "shared-browser",
+  "id": "@kbn/change-point-chart-viewer",
+  "owner": "@elastic/ml-ui",
+  "group": "platform",
+  "visibility": "shared"
+}

src/platform/packages/shared/kbn-change-point-chart-viewer/moon.extend.yml

@@ -0,0 +1,2 @@
+dependsOn:
+  - '@kbn/embeddable-plugin'

src/platform/packages/shared/kbn-change-point-chart-viewer/moon.yml

@@ -0,0 +1,50 @@
+# This file is generated by the @kbn/moon package. Any manual edits will be erased!
+#  To extend this, write your extensions/overrides to 'moon.extend.yml'
+#  then regenerate this file with: 'node scripts/regenerate_moon_projects.js --update --filter @kbn/change-point-chart-viewer'
+
+$schema: https://moonrepo.dev/schemas/project.json
+id: '@kbn/change-point-chart-viewer'
+layer: unknown
+owners:
+  defaultOwner: '@elastic/ml-ui'
+toolchains:
+  default: node
+language: typescript
+project:
+  title: '@kbn/change-point-chart-viewer'
+  description: Moon project for @kbn/change-point-chart-viewer
+  channel: ''
+  owner: '@elastic/ml-ui'
+  sourceRoot: src/platform/packages/shared/kbn-change-point-chart-viewer
+dependsOn:
+  - '@kbn/data-plugin'
+  - '@kbn/es-query'
+  - '@kbn/esql-utils'
+  - '@kbn/expressions-plugin'
+  - '@kbn/i18n'
+  - '@kbn/lens-embeddable-utils'
+  - '@kbn/lens-plugin'
+  - '@kbn/react-hooks'
+  - '@kbn/shared-ux-error-boundary'
+  - '@kbn/shared-ux-utility'
+  - '@kbn/ui-actions-plugin'
+  - '@kbn/unified-histogram'
+  - '@kbn/embeddable-plugin'
+  - '@kbn/esql-types'
+  - '@kbn/esql-language'
+  - '@kbn/embeddable-plugin'
+tags:
+  - shared-browser
+  - package
+  - prod
+  - group-platform
+  - shared
+  - jest-unit-tests
+fileGroups:
+  src:
+    - '**/*.ts'
+    - '**/*.tsx'
+    - '!target/**/*'
+  jest-config:
+    - jest.config.js
+tasks: {}

src/platform/packages/shared/kbn-change-point-chart-viewer/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "@kbn/change-point-chart-viewer",
+  "private": true,
+  "version": "1.0.0",
+  "license": "Elastic License 2.0 OR AGPL-3.0-only OR SSPL-1.0"
+}

src/platform/packages/shared/kbn-change-point-chart-viewer/src/change_point_experience_grid.test.tsx

@@ -0,0 +1,205 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+import React from 'react';
+import { render, screen } from '@testing-library/react';
+import {
+  KibanaErrorBoundaryProvider,
+  KibanaSectionErrorBoundary,
+} from '@kbn/shared-ux-error-boundary';
+import { ChangePointExperienceGrid } from './change_point_experience_grid';
+import type { UnifiedChangePointGridProps } from './types';
+
+// The APM client is pulled in transitively by the error boundary package.
+jest.mock('@elastic/apm-rum');
+
+jest.mock('@kbn/unified-histogram', () => ({
+  // Render children directly so we can test the grid content in isolation.
+  ChartSectionTemplate: ({ children }: { children?: React.ReactNode }) => <>{children}</>,
+}));
+
+jest.mock('@kbn/esql-utils', () => ({
+  getChangePointSeriesColumns: jest.fn().mockReturnValue(undefined),
+}));
+
+jest.mock('./utils/derive_change_point_cards', () => ({
+  buildChangePointCards: jest.fn().mockReturnValue([]),
+}));
+
+jest.mock('./utils/get_esql_query', () => ({
+  getEsqlQuery: jest.fn().mockReturnValue('FROM logs-* | CHANGE_POINT count ON @timestamp'),
+}));
+
+// Stub out ChangePointExperienceGridContent so happy-path tests don't need Lens.
+jest.mock('./change_point_experience_grid_content', () => ({
+  ChangePointExperienceGridContent: () => (
+    <div data-test-subj="changePointExperienceGridContent">grid content stub</div>
+  ),
+}));
+
+// Render EuiDelayRender children immediately to avoid timer flakiness in loading tests.
+jest.mock('@elastic/eui', () => {
+  const actual = jest.requireActual('@elastic/eui');
+  return {
+    ...actual,
+    EuiDelayRender: ({ children }: { children?: React.ReactNode }) => <>{children}</>,
+  };
+});
+
+// Minimal fetchParams with only the fields the grid reads directly.
+const fetchParams = {
+  query: { esql: 'FROM logs-* | CHANGE_POINT count ON @timestamp' },
+  table: { columns: [], rows: [] },
+  timeRange: { from: 'now-15m', to: 'now' },
+  relativeTimeRange: { from: 'now-15m', to: 'now' },
+  filters: [],
+  esqlVariables: [],
+} as unknown as UnifiedChangePointGridProps['fetchParams'];
+
+const fetchParamsWithRows = {
+  ...fetchParams,
+  table: {
+    columns: [{ id: '@timestamp' }, { id: 'count' }, { id: 'type' }, { id: 'pvalue' }],
+    rows: [
+      { '@timestamp': '2024-01-15T00:00:00.000Z', count: 5, type: 'mean_shift', pvalue: 0.001 },
+    ],
+  },
+} as unknown as UnifiedChangePointGridProps['fetchParams'];
+
+const minimalProps = {
+  services: {} as never,
+  fetchParams,
+  fetch$: {} as never,
+  isComponentVisible: true,
+  isTabSelected: true,
+  renderToggleActions: () => undefined,
+};
+
+/**
+ * Mirrors the error boundary structure used in LazyChangePointExperienceGrid:
+ *
+ *   <KibanaErrorBoundaryProvider analytics={undefined}>
+ *     <KibanaSectionErrorBoundary sectionName="Change point charts">
+ *       <ChangePointExperienceGrid .../>
+ *     </KibanaSectionErrorBoundary>
+ *   </KibanaErrorBoundaryProvider>
+ */
+const renderWithBoundary = (props = minimalProps) =>
+  render(
+    <KibanaErrorBoundaryProvider analytics={undefined}>
+      <KibanaSectionErrorBoundary sectionName="Change point charts">
+        <ChangePointExperienceGrid {...props} />
+      </KibanaSectionErrorBoundary>
+    </KibanaErrorBoundaryProvider>
+  );
+
+describe('ChangePointExperienceGrid error boundary integration', () => {
+  beforeEach(() => {
+    // Suppress the expected React error-boundary console output so test output stays clean.
+    jest.spyOn(console, 'error').mockImplementation(() => {});
+  });
+
+  afterEach(() => {
+    jest.restoreAllMocks();
+    jest.requireMock('./utils/derive_change_point_cards').buildChangePointCards.mockReturnValue([]);
+  });
+
+  it('renders the grid without errors under normal conditions', () => {
+    // buildChangePointCards returns [] by default → "No change points" empty-prompt branch.
+    const { container } = renderWithBoundary();
+    // The section error boundary UI must NOT be present.
+    expect(screen.queryByTestId('sectionErrorBoundaryPromptHeader')).not.toBeInTheDocument();
+    // Some DOM output must exist (the grid renders at minimum an empty container).
+    expect(container.firstChild).not.toBeNull();
+  });
+
+  it('shows the section error boundary UI instead of crashing when buildChangePointCards throws', () => {
+    // Simulate the kind of synchronous render-time crash the error boundary is there to catch
+    // (e.g. malformed data, unexpected null reference inside a memoised helper).
+    jest
+      .requireMock('./utils/derive_change_point_cards')
+      .buildChangePointCards.mockImplementation(() => {
+        throw new Error('Simulated crash in buildChangePointCards');
+      });
+
+    renderWithBoundary();
+
+    // The error boundary should have caught the throw and rendered its fallback heading.
+    expect(screen.getByTestId('sectionErrorBoundaryPromptHeader')).toBeInTheDocument();
+    // The normal grid output should not be present.
+    expect(screen.queryByText('No change points detected.')).not.toBeInTheDocument();
+  });
+});
+
+describe('ChangePointExperienceGrid UI states', () => {
+  const { buildChangePointCards, getChangePointSeriesColumns } = {
+    buildChangePointCards: () =>
+      jest.requireMock('./utils/derive_change_point_cards').buildChangePointCards,
+    getChangePointSeriesColumns: () =>
+      jest.requireMock('@kbn/esql-utils').getChangePointSeriesColumns,
+  };
+
+  afterEach(() => {
+    buildChangePointCards().mockReturnValue([]);
+    getChangePointSeriesColumns().mockReturnValue(undefined);
+  });
+
+  it('shows "No results yet" when not loading and table has no rows', () => {
+    render(
+      <ChangePointExperienceGrid
+        {...minimalProps}
+        fetchParams={fetchParams}
+        isChartLoading={false}
+      />
+    );
+    expect(screen.getByText('No results yet')).toBeInTheDocument();
+  });
+
+  it('shows "No change point series to chart" when table has rows but no cards', () => {
+    buildChangePointCards().mockReturnValue([]);
+    getChangePointSeriesColumns().mockReturnValue(undefined);
+    render(
+      <ChangePointExperienceGrid
+        {...minimalProps}
+        fetchParams={fetchParamsWithRows}
+        isChartLoading={false}
+      />
+    );
+    expect(screen.getByText('No change point series to chart')).toBeInTheDocument();
+  });
+
+  it('shows a skeleton when loading and table has no rows', () => {
+    render(
+      <ChangePointExperienceGrid
+        {...minimalProps}
+        fetchParams={fetchParams}
+        isChartLoading={true}
+      />
+    );
+    // EuiSkeletonText renders multiple lines; at least one should be present.
+    const skeleton = document.querySelector('.euiSkeletonText');
+    expect(skeleton).not.toBeNull();
+  });
+
+  it('renders grid content when table has rows and cards are available', () => {
+    buildChangePointCards().mockReturnValue([{ id: 'card-1', title: 'Series 1' }]);
+    getChangePointSeriesColumns().mockReturnValue({
+      valueColumn: 'count',
+      timeColumn: '@timestamp',
+    });
+    render(
+      <ChangePointExperienceGrid
+        {...minimalProps}
+        fetchParams={fetchParamsWithRows}
+        isChartLoading={false}
+      />
+    );
+    expect(screen.getByTestId('changePointExperienceGridContent')).toBeInTheDocument();
+  });
+});