[Discover Session][Tabs] Tab preview (#214090)

- Closes https://github.com/elastic/kibana/issues/214554

## Summary

This PR:
- adds TabPreview component, which is visible when you hover over a
particular tab
- adds tests for TabPreview component

About TabPreview component
- EUI doesn't have a component, which would suit for our needs, hence a
custom component activated on hover
- TabPreview should activate (with 500ms of delay) after hovering over a
whole tab
- It should hide when we click action button in the tab or we open
editing name mode
- It shouldn't appear on hover when we have tab context menu open or
we're editing a title
- For now the data inside is mocked (besides of title), so you can see
random queries and statuses each time you hover over the tab
- Preview should not overflow the screen if there are a lot of tabs and
they're "touching" right side of the screen


https://github.com/user-attachments/assets/da0a47dd-b594-4c20-b76c-49e6889f3814



## Testing

Two options are possible:

1. start Storybook with `yarn storybook unified_tabs` and navigate to
`http://localhost:9001`.
2. start Kibana with `yarn start --run-examples`. Then navigate to the
Unified Tabs example plugin
`http://localhost:5601/app/unifiedTabsExamples`.

### Checklist
- [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

---------

Co-authored-by: Julia Rechkunova <julia.rechkunova@elastic.co>
Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

examples/unified_tabs_examples/public/example_app.tsx

@@ -25,9 +25,33 @@ import type { DataView } from '@kbn/data-views-plugin/public';
 import type { DataViewField } from '@kbn/data-views-plugin/public';
 import type { DataViewPickerProps } from '@kbn/unified-search-plugin/public';
 import { type TabItem, UnifiedTabs, useNewTabProps } from '@kbn/unified-tabs';
+import { type TabPreviewData, TabStatus } from '@kbn/unified-tabs';
 import { PLUGIN_ID, PLUGIN_NAME } from '../common';
 import { FieldListSidebar, FieldListSidebarProps } from './field_list_sidebar';
 
+// TODO: replace with real data when ready
+const TAB_CONTENT_MOCK: TabPreviewData[] = [
+  {
+    query: {
+      esql: 'FROM logs-* | FIND ?findText | WHERE host.name == ?hostName AND log.level == ?logLevel',
+    },
+    status: TabStatus.SUCCESS,
+  },
+  {
+    query: {
+      esql: 'FROM logs-* | FIND ?findText | WHERE host.name == ?hostName AND log.level == ?logLevel',
+    },
+    status: TabStatus.RUNNING,
+  },
+  {
+    query: {
+      language: 'kql',
+      query: 'agent.name : "activemq-integrations-5f6677988-hjp58"',
+    },
+    status: TabStatus.ERROR,
+  },
+];
+
 interface UnifiedTabsExampleAppProps {
   services: FieldListSidebarProps['services'];
   setHeaderActionMenu: AppMountParameters['setHeaderActionMenu'];
@@ -102,6 +126,9 @@ export const UnifiedTabsExampleApp: React.FC<UnifiedTabsExampleAppProps> = ({
               services={services}
               onChanged={() => {}}
               createItem={getNewTabDefaultProps}
+              getPreviewData={
+                () => TAB_CONTENT_MOCK[Math.floor(Math.random() * TAB_CONTENT_MOCK.length)] // TODO change mock to real data when ready
+              }
               renderContent={({ label }) => {
                 return (
                   <EuiFlexGroup direction="column" gutterSize="none">

src/platform/packages/shared/kbn-unified-tabs/index.ts

@@ -7,7 +7,8 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
-export type { TabItem } from './src/types';
+export type { TabItem, TabPreviewData } from './src/types';
+export { TabStatus } from './src/types';
 export {
   TabbedContent as UnifiedTabs,
   type TabbedContentProps as UnifiedTabsProps,

src/platform/packages/shared/kbn-unified-tabs/src/components/tab/tab.test.tsx

@@ -12,6 +12,7 @@ import { render, screen, fireEvent } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { Tab } from './tab';
 import { MAX_TAB_WIDTH, MIN_TAB_WIDTH } from '../../constants';
+import { TabStatus } from '../../types';
 import { servicesMock } from '../../../__mocks__/services';
 
 const tabItem = {
@@ -28,6 +29,13 @@ const tabsSizeConfig = {
   regularTabMinWidth: MIN_TAB_WIDTH,
 };
 
+const previewQuery = {
+  query: {
+    esql: 'SELECT * FROM table',
+  },
+  status: TabStatus.SUCCESS,
+};
+
 describe('Tab', () => {
   it('renders tab', async () => {
     const onLabelEdited = jest.fn();
@@ -44,10 +52,13 @@ describe('Tab', () => {
         onLabelEdited={onLabelEdited}
         onSelect={onSelect}
         onClose={onClose}
+        tabPreviewData={previewQuery}
       />
     );
 
-    expect(screen.getByText(tabItem.label)).toBeInTheDocument();
+    const tabButton = screen.getByTestId(tabButtonTestSubj);
+    expect(tabButton).toBeInTheDocument();
+    expect(tabButton).toHaveTextContent(tabItem.label);
 
     const tab = screen.getByRole('tab');
     expect(tab).toHaveAttribute('id', `tab-${tabItem.id}`);
@@ -56,7 +67,6 @@ describe('Tab', () => {
     expect(onSelect).toHaveBeenCalled();
     expect(onClose).not.toHaveBeenCalled();
 
-    const tabButton = screen.getByTestId(tabButtonTestSubj);
     tabButton.click();
     expect(onSelect).toHaveBeenCalledTimes(2);
 
@@ -88,6 +98,7 @@ describe('Tab', () => {
         onLabelEdited={jest.fn()}
         onSelect={jest.fn()}
         onClose={jest.fn()}
+        tabPreviewData={previewQuery}
       />
     );
 
@@ -117,11 +128,12 @@ describe('Tab', () => {
         onLabelEdited={onLabelEdited}
         onSelect={onSelect}
         onClose={onClose}
+        tabPreviewData={previewQuery}
       />
     );
 
     expect(screen.queryByTestId(tabButtonTestSubj)).toBeInTheDocument();
-    await userEvent.dblClick(screen.getByText(tabItem.label));
+    await userEvent.dblClick(screen.getByTestId(tabButtonTestSubj));
     expect(onSelect).toHaveBeenCalled();
     expect(screen.queryByTestId(tabButtonTestSubj)).not.toBeInTheDocument();
 
@@ -151,11 +163,12 @@ describe('Tab', () => {
         onLabelEdited={onLabelEdited}
         onSelect={onSelect}
         onClose={onClose}
+        tabPreviewData={previewQuery}
       />
     );
 
     expect(screen.queryByTestId(tabButtonTestSubj)).toBeInTheDocument();
-    await userEvent.dblClick(screen.getByText(tabItem.label));
+    await userEvent.dblClick(screen.getByTestId(tabButtonTestSubj));
     expect(onSelect).toHaveBeenCalled();
     expect(screen.queryByTestId(tabButtonTestSubj)).not.toBeInTheDocument();
 

src/platform/packages/shared/kbn-unified-tabs/src/components/tab/tab.tsx

@@ -15,14 +15,21 @@ import {
   EuiFlexGroup,
   EuiFlexItem,
   EuiText,
-  EuiThemeComputed,
   useEuiTheme,
+  type EuiThemeComputed,
 } from '@elastic/eui';
 import { TabMenu } from '../tab_menu';
 import { EditTabLabel, type EditTabLabelProps } from './edit_tab_label';
 import { getTabAttributes } from '../../utils/get_tab_attributes';
-import type { TabItem, TabsSizeConfig, GetTabMenuItems, TabsServices } from '../../types';
+import type {
+  TabItem,
+  TabsSizeConfig,
+  GetTabMenuItems,
+  TabsServices,
+  TabPreviewData,
+} from '../../types';
 import { TabWithBackground } from '../tabs_visual_glue_to_header/tab_with_background';
+import { TabPreview } from '../tab_preview';
 
 export interface TabProps {
   item: TabItem;
@@ -34,6 +41,7 @@ export interface TabProps {
   onLabelEdited: EditTabLabelProps['onLabelEdited'];
   onSelect: (item: TabItem) => Promise<void>;
   onClose: ((item: TabItem) => Promise<void>) | undefined;
+  tabPreviewData: TabPreviewData;
 }
 
 export const Tab: React.FC<TabProps> = (props) => {
@@ -47,10 +55,13 @@ export const Tab: React.FC<TabProps> = (props) => {
     onLabelEdited,
     onSelect,
     onClose,
+    tabPreviewData,
   } = props;
   const { euiTheme } = useEuiTheme();
   const tabRef = useRef<HTMLDivElement | null>(null);
   const [isInlineEditActive, setIsInlineEditActive] = useState<boolean>(false);
+  const [showPreview, setShowPreview] = useState<boolean>(false);
+  const [isActionPopoverOpen, setActionPopover] = useState<boolean>(false);
 
   const closeButtonLabel = i18n.translate('unifiedTabs.closeTabButton', {
     defaultMessage: 'Close session',
@@ -60,9 +71,12 @@ export const Tab: React.FC<TabProps> = (props) => {
     defaultMessage: 'Click to select or double-click to edit session name',
   });
 
+  const hidePreview = () => setShowPreview(false);
+
   const onSelectEvent = useCallback(
     async (event: MouseEvent<HTMLElement>) => {
       event.stopPropagation();
+      hidePreview();
 
       if (!isSelected) {
         await onSelect(item);
@@ -89,6 +103,11 @@ export const Tab: React.FC<TabProps> = (props) => {
     [onSelectEvent]
   );
 
+  const handleDoubleClick = useCallback(() => {
+    setIsInlineEditActive(true);
+    hidePreview();
+  }, []);
+
   const mainTabContent = (
     <EuiFlexGroup
       alignItems="center"
@@ -111,10 +130,9 @@ export const Tab: React.FC<TabProps> = (props) => {
               css={getTabButtonCss(euiTheme)}
               className="unifiedTabs__tabBtn"
               data-test-subj={`unifiedTabs_selectTabBtn_${item.id}`}
-              title={item.label}
               type="button"
               onClick={onSelectEvent}
-              onDoubleClick={() => setIsInlineEditActive(true)}
+              onDoubleClick={handleDoubleClick}
             >
               <EuiText color="inherit" size="s" css={getTabLabelCss(euiTheme)}>
                 {item.label}
@@ -124,7 +142,12 @@ export const Tab: React.FC<TabProps> = (props) => {
               <EuiFlexGroup responsive={false} direction="row" gutterSize="none">
                 {!!getTabMenuItems && (
                   <EuiFlexItem grow={false} className="unifiedTabs__tabMenuBtn">
-                    <TabMenu item={item} getTabMenuItems={getTabMenuItems} />
+                    <TabMenu
+                      item={item}
+                      getTabMenuItems={getTabMenuItems}
+                      isPopoverOpen={isActionPopoverOpen}
+                      setPopover={setActionPopover}
+                    />
                   </EuiFlexItem>
                 )}
                 {!!onClose && (
@@ -148,18 +171,26 @@ export const Tab: React.FC<TabProps> = (props) => {
   );
 
   return (
-    <TabWithBackground
-      {...getTabAttributes(item, tabContentId)}
-      ref={tabRef}
-      role="tab"
-      aria-selected={isSelected}
-      data-test-subj={`unifiedTabs_tab_${item.id}`}
-      isSelected={isSelected}
-      services={services}
-      onClick={onClickEvent}
+    <TabPreview
+      showPreview={showPreview}
+      setShowPreview={setShowPreview}
+      stopPreviewOnHover={isInlineEditActive || isActionPopoverOpen}
+      tabPreviewData={tabPreviewData}
+      tabItem={item}
     >
-      {mainTabContent}
-    </TabWithBackground>
+      <TabWithBackground
+        {...getTabAttributes(item, tabContentId)}
+        ref={tabRef}
+        role="tab"
+        aria-selected={isSelected}
+        data-test-subj={`unifiedTabs_tab_${item.id}`}
+        isSelected={isSelected}
+        services={services}
+        onClick={onClickEvent}
+      >
+        {mainTabContent}
+      </TabWithBackground>
+    </TabPreview>
   );
 };
 

src/platform/packages/shared/kbn-unified-tabs/src/components/tab_menu/tab_menu.tsx

@@ -7,7 +7,7 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
-import React, { useCallback, useMemo, useState } from 'react';
+import React, { useCallback, useMemo } from 'react';
 import { i18n } from '@kbn/i18n';
 import {
   EuiButtonIcon,
@@ -22,10 +22,16 @@ import type { TabItem, GetTabMenuItems } from '../../types';
 export interface TabMenuProps {
   item: TabItem;
   getTabMenuItems: GetTabMenuItems;
+  isPopoverOpen: boolean;
+  setPopover: React.Dispatch<React.SetStateAction<boolean>>;
 }
 
-export const TabMenu: React.FC<TabMenuProps> = ({ item, getTabMenuItems }) => {
-  const [isPopoverOpen, setPopover] = useState<boolean>(false);
+export const TabMenu: React.FC<TabMenuProps> = ({
+  item,
+  getTabMenuItems,
+  isPopoverOpen,
+  setPopover,
+}) => {
   const contextMenuPopoverId = useGeneratedHtmlId();
 
   const menuButtonLabel = i18n.translate('unifiedTabs.tabMenuButton', {

src/platform/packages/shared/kbn-unified-tabs/src/components/tab_preview/index.ts

@@ -0,0 +1,10 @@
+/*
+ * 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 { TabPreview } from './tab_preview';

src/platform/packages/shared/kbn-unified-tabs/src/components/tab_preview/tab_preview.test.tsx

@@ -0,0 +1,108 @@
+/*
+ * 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, fireEvent, waitFor } from '@testing-library/react';
+import { TabPreview } from './tab_preview';
+import type { TabPreviewData, TabItem } from '../../types';
+import { TabStatus } from '../../types';
+
+const tabPreviewData: TabPreviewData = {
+  query: {
+    esql: 'SELECT * FROM table',
+  },
+  status: TabStatus.SUCCESS,
+};
+
+const tabItem: TabItem = {
+  id: 'test-id',
+  label: 'test-label',
+};
+
+const previewTestSubj = `unifiedTabs_tabPreview_${tabItem.id}`;
+
+describe('TabPreview', () => {
+  it('should call setShowPreview when mouse enters and change opacity after a delay', async () => {
+    const setShowPreview = jest.fn();
+
+    render(
+      <TabPreview
+        showPreview={false}
+        setShowPreview={setShowPreview}
+        tabPreviewData={tabPreviewData}
+        tabItem={tabItem}
+        stopPreviewOnHover={false}
+        previewDelay={0}
+      >
+        <span>Tab Example</span>
+      </TabPreview>
+    );
+
+    const previewContainer = screen.getByTestId(previewTestSubj);
+    expect(previewContainer).toBeInTheDocument();
+    expect(previewContainer).toHaveStyle('opacity: 0');
+
+    const tabElement = screen.getByText('Tab Example');
+    fireEvent.mouseEnter(tabElement);
+
+    await waitFor(() => {
+      expect(setShowPreview).toHaveBeenCalledWith(true);
+    });
+  });
+
+  it('should call setShowPreview when mouse leaves', async () => {
+    const setShowPreview = jest.fn();
+
+    render(
+      <TabPreview
+        showPreview={true}
+        setShowPreview={setShowPreview}
+        tabPreviewData={tabPreviewData}
+        tabItem={tabItem}
+        stopPreviewOnHover={false}
+      >
+        <span>Tab Example</span>
+      </TabPreview>
+    );
+
+    const previewContainer = screen.getByTestId(previewTestSubj);
+    expect(previewContainer).toBeInTheDocument();
+    expect(previewContainer).toHaveStyle('opacity: 1');
+
+    const tabElement = screen.getByText('Tab Example');
+    fireEvent.mouseLeave(tabElement);
+
+    await waitFor(() => {
+      expect(setShowPreview).toHaveBeenCalledWith(false);
+    });
+  });
+
+  it('should not call setShowPreview when stopPreviewOnHover is true', async () => {
+    const setShowPreview = jest.fn();
+
+    render(
+      <TabPreview
+        showPreview={false}
+        setShowPreview={setShowPreview}
+        tabPreviewData={tabPreviewData}
+        tabItem={tabItem}
+        stopPreviewOnHover={true}
+      >
+        <span>Tab Example</span>
+      </TabPreview>
+    );
+
+    const tabElement = screen.getByText('Tab Example');
+    fireEvent.mouseEnter(tabElement);
+
+    await waitFor(() => {
+      expect(setShowPreview).not.toHaveBeenCalledWith(true);
+    });
+  });
+});

src/platform/packages/shared/kbn-unified-tabs/src/components/tab_preview/tab_preview.tsx

@@ -0,0 +1,202 @@
+/*
+ * 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, { useCallback, useEffect, useState, useRef } from 'react';
+import { css } from '@emotion/react';
+import useEvent from 'react-use/lib/useEvent';
+import {
+  EuiSplitPanel,
+  EuiHealth,
+  keys,
+  useEuiTheme,
+  EuiCodeBlock,
+  EuiFlexItem,
+  EuiFlexGroup,
+  EuiLoadingSpinner,
+  EuiPortal,
+  EuiText,
+  type EuiThemeComputed,
+} from '@elastic/eui';
+import { isOfAggregateQueryType } from '@kbn/es-query';
+
+import { PREVIEW_WIDTH } from '../../constants';
+import type { TabPreviewData, TabItem } from '../../types';
+import { TabStatus } from '../../types';
+
+interface TabPreviewProps {
+  children: React.ReactNode;
+  showPreview: boolean;
+  setShowPreview: (show: boolean) => void;
+  tabItem: TabItem;
+  tabPreviewData: TabPreviewData;
+  stopPreviewOnHover?: boolean;
+  previewDelay?: number;
+}
+
+const getQueryLanguage = (tabPreviewData: TabPreviewData) => {
+  if (isOfAggregateQueryType(tabPreviewData.query)) {
+    return 'esql';
+  }
+
+  return tabPreviewData.query.language;
+};
+
+const getPreviewQuery = (tabPreviewData: TabPreviewData) => {
+  if (isOfAggregateQueryType(tabPreviewData.query)) {
+    return tabPreviewData.query.esql;
+  }
+
+  return typeof tabPreviewData.query.query === 'string' ? tabPreviewData.query.query : '';
+};
+
+export const TabPreview: React.FC<TabPreviewProps> = ({
+  children,
+  showPreview,
+  setShowPreview,
+  tabItem,
+  tabPreviewData,
+  stopPreviewOnHover,
+  previewDelay = 500,
+}) => {
+  const { euiTheme } = useEuiTheme();
+  const [previewTimer, setPreviewTimer] = useState<NodeJS.Timeout | null>(null);
+  const tabRef = useRef<HTMLSpanElement>(null);
+  const [tabPosition, setTabPosition] = useState({ top: 0, left: 0 });
+
+  useEffect(() => {
+    if (showPreview && tabRef.current) {
+      const rect = tabRef.current.getBoundingClientRect();
+      const windowWidth = window.innerWidth;
+
+      // Check if preview would extend beyond right edge
+      const wouldExtendBeyondRight = rect.left + PREVIEW_WIDTH > windowWidth;
+
+      // Calculate left position based on screen edge constraints
+      let leftPosition = rect.left + window.scrollX;
+
+      if (wouldExtendBeyondRight) {
+        // Align right edge of preview with right edge of window
+        leftPosition = windowWidth - PREVIEW_WIDTH + window.scrollX;
+      }
+
+      setTabPosition({
+        top: rect.bottom + window.scrollY,
+        left: leftPosition,
+      });
+    }
+  }, [showPreview]);
+
+  const onKeyDown = useCallback(
+    (event: KeyboardEvent) => {
+      if (event.key === keys.ESCAPE) {
+        setShowPreview(false);
+      }
+    },
+    [setShowPreview]
+  );
+
+  useEvent('keydown', onKeyDown);
+
+  useEffect(() => {
+    return () => {
+      if (previewTimer) {
+        clearTimeout(previewTimer);
+      }
+    };
+  }, [previewTimer]);
+
+  const handleMouseEnter = useCallback(() => {
+    if (stopPreviewOnHover) return;
+
+    const timer = setTimeout(() => {
+      setShowPreview(true);
+    }, previewDelay);
+
+    setPreviewTimer(timer);
+  }, [previewDelay, setShowPreview, stopPreviewOnHover]);
+
+  const handleMouseLeave = useCallback(() => {
+    if (previewTimer) {
+      clearTimeout(previewTimer);
+      setPreviewTimer(null);
+    }
+
+    setShowPreview(false);
+  }, [previewTimer, setShowPreview]);
+
+  return (
+    <div>
+      <span onMouseEnter={handleMouseEnter} onMouseLeave={handleMouseLeave} ref={tabRef}>
+        {children}
+      </span>
+      <EuiPortal>
+        <EuiSplitPanel.Outer
+          grow
+          css={getPreviewContainerCss(euiTheme, showPreview, tabPosition)}
+          data-test-subj={`unifiedTabs_tabPreview_${tabItem.id}`}
+        >
+          <EuiSplitPanel.Inner paddingSize="none" css={getSplitPanelCss(euiTheme)}>
+            <EuiCodeBlock
+              language={getQueryLanguage(tabPreviewData)}
+              transparentBackground
+              paddingSize="none"
+            >
+              {getPreviewQuery(tabPreviewData)}
+            </EuiCodeBlock>
+          </EuiSplitPanel.Inner>
+          <EuiSplitPanel.Inner
+            grow={false}
+            color="subdued"
+            paddingSize="none"
+            css={getSplitPanelCss(euiTheme)}
+          >
+            {tabPreviewData.status === TabStatus.RUNNING ? (
+              <EuiFlexGroup alignItems="center" gutterSize="s" responsive={false}>
+                <EuiFlexItem grow={false}>
+                  <EuiLoadingSpinner />
+                </EuiFlexItem>
+                <EuiFlexItem>
+                  <EuiText>{tabItem.label}</EuiText>
+                </EuiFlexItem>
+              </EuiFlexGroup>
+            ) : (
+              <EuiHealth color={tabPreviewData.status} textSize="m">
+                {tabItem.label}
+              </EuiHealth>
+            )}
+          </EuiSplitPanel.Inner>
+        </EuiSplitPanel.Outer>
+      </EuiPortal>
+    </div>
+  );
+};
+
+const getPreviewContainerCss = (
+  euiTheme: EuiThemeComputed,
+  showPreview: boolean,
+  tabPosition: { top: number; left: number }
+) => {
+  return css`
+    position: absolute;
+    top: ${tabPosition.top}px;
+    left: ${tabPosition.left}px;
+    z-index: 10000;
+    margin-top: ${euiTheme.size.xs};
+    width: ${PREVIEW_WIDTH}px;
+    opacity: ${showPreview ? 1 : 0};
+    transition: opacity ${euiTheme.animation.normal} ease;
+  `;
+};
+
+const getSplitPanelCss = (euiTheme: EuiThemeComputed) => {
+  return css`
+    padding-inline: ${euiTheme.size.base};
+    padding-block: ${euiTheme.size.s};
+  `;
+};

src/platform/packages/shared/kbn-unified-tabs/src/components/tabbed_content/tabbed_content.tsx

@@ -21,7 +21,7 @@ import {
   closeOtherTabs,
   closeTabsToTheRight,
 } from '../../utils/manage_tabs';
-import type { TabItem, TabsServices } from '../../types';
+import type { TabItem, TabsServices, TabPreviewData } from '../../types';
 
 export interface TabbedContentProps extends Pick<TabsBarProps, 'maxItemsCount'> {
   initialItems: TabItem[];
@@ -31,6 +31,7 @@ export interface TabbedContentProps extends Pick<TabsBarProps, 'maxItemsCount'>
   renderContent: (selectedItem: TabItem) => React.ReactNode;
   createItem: () => TabItem;
   onChanged: (state: TabbedContentState) => void;
+  getPreviewData: (item: TabItem) => TabPreviewData;
 }
 
 export interface TabbedContentState {
@@ -46,6 +47,7 @@ export const TabbedContent: React.FC<TabbedContentProps> = ({
   renderContent,
   createItem,
   onChanged,
+  getPreviewData,
 }) => {
   const [tabContentId] = useState(() => htmlIdGenerator()());
   const [state, _setState] = useState<TabbedContentState>(() => {
@@ -134,6 +136,7 @@ export const TabbedContent: React.FC<TabbedContentProps> = ({
           onLabelEdited={onLabelEdited}
           onSelect={onSelect}
           onClose={onClose}
+          getPreviewData={getPreviewData}
         />
       </EuiFlexItem>
       {selectedItem ? (

src/platform/packages/shared/kbn-unified-tabs/src/components/tabs_bar/tabs_bar.test.tsx

@@ -10,6 +10,7 @@
 import React from 'react';
 import { render, screen } from '@testing-library/react';
 import { TabsBar } from './tabs_bar';
+import { TabStatus } from '../../types';
 import { servicesMock } from '../../../__mocks__/services';
 
 const items = Array.from({ length: 5 }).map((_, i) => ({
@@ -25,9 +26,17 @@ describe('TabsBar', () => {
     const onSelect = jest.fn();
     const onLabelEdited = jest.fn();
     const onClose = jest.fn();
+    const getPreviewData = jest.fn();
 
     const selectedItem = items[0];
 
+    getPreviewData.mockReturnValue({
+      query: {
+        esql: 'SELECT * FROM table',
+      },
+      status: TabStatus.SUCCESS,
+    });
+
     render(
       <TabsBar
         tabContentId={tabContentId}
@@ -38,6 +47,7 @@ describe('TabsBar', () => {
         onLabelEdited={onLabelEdited}
         onSelect={onSelect}
         onClose={onClose}
+        getPreviewData={getPreviewData}
       />
     );
 
@@ -46,7 +56,9 @@ describe('TabsBar', () => {
 
     items.forEach((tabItem, index) => {
       const tab = tabs[index];
-      expect(screen.getByText(tabItem.label)).toBeInTheDocument();
+      const tabButton = screen.getByTestId(`unifiedTabs_selectTabBtn_${tabItem.id}`);
+      expect(tabButton).toBeInTheDocument();
+      expect(tabButton).toHaveTextContent(tabItem.label);
       expect(tab).toHaveAttribute('id', `tab-${tabItem.id}`);
       expect(tab).toHaveAttribute('aria-controls', tabContentId);
       expect(tab).toHaveAttribute(
@@ -55,7 +67,7 @@ describe('TabsBar', () => {
       );
     });
 
-    const tab = screen.getByText(items[1].label);
+    const tab = screen.getByTestId(`unifiedTabs_selectTabBtn_${items[1].id}`);
     tab.click();
     expect(onSelect).toHaveBeenCalled();
 

src/platform/packages/shared/kbn-unified-tabs/src/components/tabs_bar/tabs_bar.tsx

@@ -12,7 +12,7 @@ import { i18n } from '@kbn/i18n';
 import { css } from '@emotion/react';
 import { EuiButtonIcon, EuiFlexGroup, EuiFlexItem, useEuiTheme } from '@elastic/eui';
 import { Tab, type TabProps } from '../tab';
-import type { TabItem, TabsServices } from '../../types';
+import type { TabItem, TabsServices, TabPreviewData } from '../../types';
 import { getTabIdAttribute } from '../../utils/get_tab_attributes';
 import { useResponsiveTabs } from '../../hooks/use_responsive_tabs';
 import { TabsBarWithBackground } from '../tabs_visual_glue_to_header/tabs_bar_with_background';
@@ -30,6 +30,7 @@ export type TabsBarProps = Pick<
   maxItemsCount?: number;
   services: TabsServices;
   onAdd: () => Promise<void>;
+  getPreviewData: (item: TabItem) => TabPreviewData;
 };
 
 export const TabsBar: React.FC<TabsBarProps> = ({
@@ -43,6 +44,7 @@ export const TabsBar: React.FC<TabsBarProps> = ({
   onLabelEdited,
   onSelect,
   onClose,
+  getPreviewData,
 }) => {
   const { euiTheme } = useEuiTheme();
   const [tabsContainerWithPlusElement, setTabsContainerWithPlusElement] =
@@ -107,6 +109,7 @@ export const TabsBar: React.FC<TabsBarProps> = ({
                   onLabelEdited={onLabelEdited}
                   onSelect={onSelect}
                   onClose={items.length > 1 ? onClose : undefined} // prevents closing the last tab
+                  tabPreviewData={getPreviewData(item)}
                 />
               ))}
             </EuiFlexGroup>

src/platform/packages/shared/kbn-unified-tabs/src/constants.ts

@@ -11,3 +11,5 @@ export const MAX_TAB_LABEL_LENGTH = 500;
 
 export const MAX_TAB_WIDTH = 280;
 export const MIN_TAB_WIDTH = 96;
+
+export const PREVIEW_WIDTH = 280;

src/platform/packages/shared/kbn-unified-tabs/src/types.ts

@@ -7,6 +7,7 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
+import { AggregateQuery, Query } from '@kbn/es-query';
 import type { CoreStart } from '@kbn/core/public';
 
 export interface TabItem {
@@ -28,6 +29,19 @@ export interface TabsSizeConfig {
   // TODO: extend with possibly different sizes for pinned tabs
 }
 
+// TODO status value for now matches EuiHealth colors for mocking simplicity, adjust when real data is available
+export enum TabStatus {
+  SUCCESS = 'success',
+  RUNNING = 'running',
+  ERROR = 'danger',
+}
+
+// TODO adjust interface when real data is available, this currently types TAB_CONTENT_MOCK
+export interface TabPreviewData {
+  query: AggregateQuery | Query;
+  status: TabStatus;
+}
+
 export type TabMenuItem = TabMenuItemWithClick | 'divider';
 
 export type GetTabMenuItems = (item: TabItem) => TabMenuItem[];

src/platform/packages/shared/kbn-unified-tabs/tsconfig.json

@@ -4,12 +4,6 @@
     "outDir": "target/types"
   },
   "include": ["**/*.ts", "**/*.tsx"],
-  "exclude": [
-    "target/**/*"
-  ],
-  "kbn_references": [
-    "@kbn/i18n",
-    "@kbn/core-chrome-browser",
-    "@kbn/core",
-  ]
+  "exclude": ["target/**/*"],
+  "kbn_references": ["@kbn/i18n", "@kbn/es-query", "@kbn/core-chrome-browser", "@kbn/core"]
 }