Refactor: Extract root components architecture with comprehensive tests

less/hostedexplorer.less

@@ -17,38 +17,6 @@
     position: fixed;
     top: -200px;
 }
-body.isDarkMode .ms-Layer {
-    .ms-Callout-main {
-        background-color: @BaseHigh !important;
-    }
-
-    .ms-Callout-beak {
-        background-color: @BaseHigh !important;
-    }
-
-    .ms-ContextualMenu {
-        background-color: @BaseHigh !important;
-    }
-
-    .ms-Dropdown-items {
-        background-color: @BaseHigh !important;
-    }
-
-    .ms-Dropdown-item {
-        background-color: @BaseHigh !important;
-        color: @BaseLight !important;
-
-        &:hover {
-            background-color: @BaseMediumHigh !important;
-            color: @BaseLight !important;
-        }
-
-        &.is-selected {
-            background-color: @BaseMediumHigh !important;
-            color: @BaseLight !important;
-        }
-    }
-}
 
 html {
     font-family: wf_segoe-ui_normal, "Segoe UI", "Segoe WP", Tahoma, Arial, sans-serif;
@@ -161,65 +129,6 @@ body {
         }
     }
 
-    &.isDarkMode .accountSwitchContextualMenu {
-        background-color: @BaseHigh;
-
-        .ms-Callout-main {
-            background-color: @BaseHigh;
-        }
-
-        .ms-ContextualMenu-item {
-            background-color: @BaseHigh;
-        }
-
-        .ms-Dropdown {
-            .ms-Dropdown-title {
-                background-color: @BaseDark;
-                color: @BaseLight;
-                border-color: @BaseMediumHigh;
-            }
-
-            .ms-Dropdown-caretDownWrapper {
-                color: @BaseLight;
-            }
-
-            &:hover .ms-Dropdown-title {
-                background-color: @BaseHigh;
-                color: @BaseLight;
-                border-color: @BaseMedium;
-            }
-        }
-
-        .ms-Label {
-            color: @BaseLight;
-        }
-    }
-
-    &.isDarkMode .ms-Dropdown-callout {
-        .ms-Callout-main {
-            background-color: @BaseHigh;
-        }
-
-        .ms-Dropdown-items {
-            background-color: @BaseHigh;
-        }
-
-        .ms-Dropdown-item {
-            background-color: @BaseHigh;
-            color: @BaseLight;
-
-            &:hover {
-                background-color: @BaseMediumHigh;
-                color: @BaseLight;
-            }
-
-            &.is-selected {
-                background-color: @BaseMediumHigh;
-                color: @BaseLight;
-            }
-        }
-    }
-
     .fixedleftpane {
         background: @BaseLow;
         height: 100vh;

src/Explorer/ContainerCopy/ContainerCopyPanel.tsx

@@ -1,4 +1,5 @@
 import React, { useEffect } from "react";
+import { SidePanel } from "../../Explorer/Panes/PanelContainerComponent";
 import CopyJobCommandBar from "./CommandBar/CopyJobCommandBar";
 import "./containerCopyStyles.less";
 import { MonitorCopyJobsRefState } from "./MonitorCopyJobs/MonitorCopyJobRefState";
@@ -16,6 +17,7 @@ const ContainerCopyPanel: React.FC<ContainerCopyProps> = ({ explorer }) => {
     <div id="containerCopyWrapper" className="flexContainer hideOverflows">
       <CopyJobCommandBar explorer={explorer} />
       <MonitorCopyJobs ref={monitorCopyJobsRef} explorer={explorer} />
+      <SidePanel />
     </div>
   );
 };

src/Explorer/Controls/Settings/SettingsSubComponents/PartitionKeyComponent.tsx

@@ -187,7 +187,7 @@ export const PartitionKeyComponent: React.FC<PartitionKeyComponentProps> = ({
             <Text styles={textSubHeadingStyle}>Current {partitionKeyName.toLowerCase()}</Text>
             <Text styles={textSubHeadingStyle}>Partitioning</Text>
           </Stack>
-          <Stack tokens={{ childrenGap: 5 }} data-test="partition-key-values">
+          <Stack tokens={{ childrenGap: 5 }}>
             <Text styles={textSubHeadingStyle1}>{partitionKeyValue}</Text>
             <Text styles={textSubHeadingStyle1}>
               {isHierarchicalPartitionedContainer() ? "Hierarchical" : "Non-hierarchical"}
@@ -199,7 +199,6 @@ export const PartitionKeyComponent: React.FC<PartitionKeyComponentProps> = ({
       {!isReadOnly && (
         <>
           <MessageBar
-            data-test="partition-key-warning"
             messageBarType={MessageBarType.warning}
             messageBarIconProps={{ iconName: "WarningSolid", className: "messageBarWarningIcon" }}
             styles={darkThemeMessageBarStyles}
@@ -221,7 +220,6 @@ export const PartitionKeyComponent: React.FC<PartitionKeyComponentProps> = ({
           </Text>
           {configContext.platform !== Platform.Emulator && (
             <PrimaryButton
-              data-test="change-partition-key-button"
               styles={{ root: { width: "fit-content" } }}
               text="Change"
               onClick={startPartitionkeyChangeWorkflow}

src/Explorer/Controls/Settings/SettingsSubComponents/__snapshots__/PartitionKeyComponent.test.tsx.snap

@@ -78,7 +78,6 @@ exports[`PartitionKeyComponent renders default component and matches snapshot 1`
         </Text>
       </Stack>
       <Stack
-        data-test="partition-key-values"
         tokens={
           {
             "childrenGap": 5,
@@ -109,7 +108,6 @@ exports[`PartitionKeyComponent renders default component and matches snapshot 1`
     </Stack>
   </Stack>
   <StyledMessageBar
-    data-test="partition-key-warning"
     messageBarIconProps={
       {
         "className": "messageBarWarningIcon",
@@ -162,7 +160,6 @@ exports[`PartitionKeyComponent renders default component and matches snapshot 1`
     To change the partition key, a new destination container must be created or an existing destination container selected. Data will then be copied to the destination container.
   </Text>
   <CustomizedPrimaryButton
-    data-test="change-partition-key-button"
     onClick={[Function]}
     styles={
       {
@@ -240,7 +237,6 @@ exports[`PartitionKeyComponent renders read-only component and matches snapshot
         </Text>
       </Stack>
       <Stack
-        data-test="partition-key-values"
         tokens={
           {
             "childrenGap": 5,

src/Explorer/Panes/ChangePartitionKeyPane/ChangePartitionKeyPane.tsx

@@ -208,7 +208,7 @@ export const ChangePartitionKeyPane: React.FC<ChangePartitionKeyPaneProps> = ({
           </div>
         </Stack>
         {createNewContainer ? (
-          <Stack data-test="create-new-container-form">
+          <Stack>
             <MessageBar>All configurations except for unique keys will be copied from the source container</MessageBar>
             <Stack className="panelGroupSpacing">
               <Stack horizontal>
@@ -230,7 +230,6 @@ export const ChangePartitionKeyPane: React.FC<ChangePartitionKeyPaneProps> = ({
                 </TooltipHost>
               </Stack>
               <input
-                data-test="new-container-id-input"
                 name="collectionId"
                 id="collectionId"
                 type="text"
@@ -272,7 +271,6 @@ export const ChangePartitionKeyPane: React.FC<ChangePartitionKeyPaneProps> = ({
 
               <input
                 type="text"
-                data-test="new-container-partition-key-input"
                 id="addCollection-partitionKeyValue"
                 aria-required
                 required
@@ -306,7 +304,6 @@ export const ChangePartitionKeyPane: React.FC<ChangePartitionKeyPaneProps> = ({
                       type="text"
                       id="addCollection-partitionKeyValue"
                       key={`addCollection-partitionKeyValue_${index}`}
-                      data-test={`new-container-sub-partition-key-input-${index}`}
                       aria-required
                       required
                       size={40}
@@ -330,8 +327,6 @@ export const ChangePartitionKeyPane: React.FC<ChangePartitionKeyPaneProps> = ({
                       }}
                     />
                     <IconButton
-                      data-test={`remove-sub-partition-key-button-${index}`}
-                      ariaLabel="Remove hierarchical partition key"
                       iconProps={{ iconName: "Delete" }}
                       style={{ height: 27 }}
                       onClick={() => {
@@ -344,7 +339,6 @@ export const ChangePartitionKeyPane: React.FC<ChangePartitionKeyPaneProps> = ({
               })}
               <Stack className="panelGroupSpacing">
                 <DefaultButton
-                  data-test="add-sub-partition-key-button"
                   styles={{ root: { padding: 0, width: 200, height: 30 }, label: { fontSize: 12 } }}
                   disabled={subPartitionKeys.length >= Constants.BackendDefaults.maxNumMultiHashPartition}
                   onClick={() => setSubPartitionKeys([...subPartitionKeys, ""])}
@@ -352,11 +346,7 @@ export const ChangePartitionKeyPane: React.FC<ChangePartitionKeyPaneProps> = ({
                   Add hierarchical partition key
                 </DefaultButton>
                 {subPartitionKeys.length > 0 && (
-                  <Text
-                    data-test="hierarchical-partitioning-info-text"
-                    variant="small"
-                    style={{ color: "var(--colorNeutralForeground1)" }}
-                  >
+                  <Text variant="small" style={{ color: "var(--colorNeutralForeground1)" }}>
                     <Icon iconName="InfoSolid" className="removeIcon" tabIndex={0} /> This feature allows you to
                     partition your data with up to three levels of keys for better data distribution. Requires .NET V3,
                     Java V4 SDK, or preview JavaScript V3 SDK.{" "}
@@ -369,7 +359,7 @@ export const ChangePartitionKeyPane: React.FC<ChangePartitionKeyPaneProps> = ({
             </Stack>
           </Stack>
         ) : (
-          <Stack data-test="use-existing-container-form">
+          <Stack>
             <Stack horizontal>
               <span className="mandatoryStar">*&nbsp;</span>
               <Text className="panelTextBold" variant="small">
@@ -400,7 +390,6 @@ export const ChangePartitionKeyPane: React.FC<ChangePartitionKeyPaneProps> = ({
               }}
               defaultSelectedKey={targetCollectionId}
               responsiveMode={999}
-              ariaLabel="Existing Containers"
             />
           </Stack>
         )}

src/HostedExplorer.tsx

@@ -1,6 +1,5 @@
 import { initializeIcons } from "@fluentui/react";
 import { useBoolean } from "@fluentui/react-hooks";
-import { MessageTypes } from "Contracts/MessageTypes";
 import { AadAuthorizationFailure } from "Platform/Hosted/Components/AadAuthorizationFailure";
 import * as React from "react";
 import { render } from "react-dom";
@@ -22,33 +21,9 @@ import "./Shared/appInsights";
 import { useAADAuth } from "./hooks/useAADAuth";
 import { useConfig } from "./hooks/useConfig";
 import { useTokenMetadata } from "./hooks/usePortalAccessToken";
-import { THEME_MODE_DARK, useThemeStore } from "./hooks/useTheme";
 
 initializeIcons();
 
-if (typeof window !== "undefined") {
-  window.addEventListener("message", (event) => {
-    const messageData = event.data?.data || event.data;
-    const messageType = messageData?.type;
-
-    if (messageType === MessageTypes.UpdateTheme) {
-      const themeData = messageData?.params?.theme || messageData?.theme;
-      if (themeData && themeData.mode !== undefined) {
-        const isDark = themeData.mode === THEME_MODE_DARK;
-        useThemeStore.setState({
-          isDarkMode: isDark,
-          themeMode: themeData.mode,
-        });
-        if (isDark) {
-          document.body.classList.add("isDarkMode");
-        } else {
-          document.body.classList.remove("isDarkMode");
-        }
-      }
-    }
-  });
-}
-
 const App: React.FunctionComponent = () => {
   // For handling encrypted portal tokens sent via query paramter
   const params = new URLSearchParams(window.location.search);

src/Main.tsx

@@ -2,18 +2,9 @@
 import "./ReactDevTools";
 
 // CSS Dependencies
-import { initializeIcons, loadTheme, useTheme } from "@fluentui/react";
-import { FluentProvider, makeStyles, webDarkTheme, webLightTheme } from "@fluentui/react-components";
-import { Platform } from "ConfigContext";
-import ContainerCopyPanel from "Explorer/ContainerCopy/ContainerCopyPanel";
-import Explorer from "Explorer/Explorer";
-import { QuickstartCarousel } from "Explorer/Quickstart/QuickstartCarousel";
-import { MongoQuickstartTutorial } from "Explorer/Quickstart/Tutorials/MongoQuickstartTutorial";
-import { SQLQuickstartTutorial } from "Explorer/Quickstart/Tutorials/SQLQuickstartTutorial";
-import { userContext } from "UserContext";
+import { initializeIcons } from "@fluentui/react";
 import "allotment/dist/style.css";
 import "bootstrap/dist/css/bootstrap.css";
-import { useCarousel } from "hooks/useCarousel";
 import React from "react";
 import ReactDOM from "react-dom";
 import "../externals/jquery-ui.min.css";
@@ -24,13 +15,8 @@ import "../externals/jquery.dataTables.min.css";
 import "../externals/jquery.typeahead.min.css";
 import "../externals/jquery.typeahead.min.js";
 // Image Dependencies
-import { SidePanel } from "Explorer/Panes/PanelContainerComponent";
-import { QueryCopilotCarousel } from "Explorer/QueryCopilot/CopilotCarousel";
-import { SidebarContainer } from "Explorer/Sidebar";
-import { KeyboardShortcutRoot } from "KeyboardShortcuts";
 import "allotment/dist/style.css";
 import "../images/CosmosDB_rgb_ui_lighttheme.ico";
-import hdeConnectImage from "../images/HdeConnectCosmosDB.svg";
 import "../images/favicon.ico";
 import "../less/TableStyles/CustomizeColumns.less";
 import "../less/TableStyles/EntityEditor.less";
@@ -42,178 +28,29 @@ import "../less/infobox.less";
 import "../less/menus.less";
 import "../less/messagebox.less";
 import "../less/resourceTree.less";
-import * as StyleConstants from "./Common/StyleConstants";
 import "./Explorer/Controls/Accordion/AccordionComponent.less";
 import "./Explorer/Controls/CollapsiblePanel/CollapsiblePanelComponent.less";
-import { Dialog } from "./Explorer/Controls/Dialog";
 import "./Explorer/Controls/ErrorDisplayComponent/ErrorDisplayComponent.less";
 import "./Explorer/Controls/JsonEditor/JsonEditorComponent.less";
 import "./Explorer/Controls/Notebook/NotebookTerminalComponent.less";
 import "./Explorer/Controls/TreeComponent/treeComponent.less";
-import { ErrorBoundary } from "./Explorer/ErrorBoundary";
 import "./Explorer/Graph/GraphExplorerComponent/graphExplorer.less";
 import "./Explorer/Menus/CommandBar/CommandBarComponent.less";
-import { CommandBar } from "./Explorer/Menus/CommandBar/CommandBarComponentAdapter";
 import "./Explorer/Menus/CommandBar/ConnectionStatusComponent.less";
 import "./Explorer/Menus/CommandBar/MemoryTrackerComponent.less";
 import "./Explorer/Menus/NotificationConsole/NotificationConsole.less";
-import { NotificationConsole } from "./Explorer/Menus/NotificationConsole/NotificationConsoleComponent";
 import "./Explorer/Panes/PanelComponent.less";
 import "./Explorer/SplashScreen/SplashScreen.less";
 import "./Libs/jquery";
-import MetricScenario from "./Metrics/MetricEvents";
-import { MetricScenarioProvider, useMetricScenario } from "./Metrics/MetricScenarioProvider";
-import { ApplicationMetricPhase } from "./Metrics/ScenarioConfig";
-import { useInteractive } from "./Metrics/useMetricPhases";
-import { appThemeFabric } from "./Platform/Fabric/FabricTheme";
+import { MetricScenarioProvider } from "./Metrics/MetricScenarioProvider";
+import Root from "./RootComponents/Root";
 import "./Shared/appInsights";
-import { useConfig } from "./hooks/useConfig";
-import { useKnockoutExplorer } from "./hooks/useKnockoutExplorer";
-import { useThemeStore } from "./hooks/useTheme";
 import "./less/DarkModeMenus.less";
 import "./less/ThemeSystem.less";
+
 // Initialize icons before React is loaded
 initializeIcons(undefined, { disableWarnings: true });
 
-const useStyles = makeStyles({
-  root: {
-    height: "100vh",
-    width: "100vw",
-    backgroundColor: "var(--colorNeutralBackground1)",
-    color: "var(--colorNeutralForeground1)",
-  },
-});
-
-const App = (): JSX.Element => {
-  const config = useConfig();
-  const styles = useStyles();
-  // theme is used for application-wide styling
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
-  const theme = useTheme();
-
-  // Load Fabric theme and styles only once when platform is Fabric
-  React.useEffect(() => {
-    if (config?.platform === Platform.Fabric) {
-      loadTheme(appThemeFabric);
-      import("../less/documentDBFabric.less");
-    }
-    StyleConstants.updateStyles();
-  }, [config?.platform]);
-
-  const explorer = useKnockoutExplorer(config?.platform);
-
-  // Scenario-based health tracking: start ApplicationLoad and complete phases.
-  const { startScenario, completePhase } = useMetricScenario();
-  React.useEffect(() => {
-    startScenario(MetricScenario.ApplicationLoad);
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, []);
-
-  React.useEffect(() => {
-    if (explorer) {
-      completePhase(MetricScenario.ApplicationLoad, ApplicationMetricPhase.ExplorerInitialized);
-    }
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [explorer]);
-
-  if (!explorer) {
-    return <LoadingExplorer />;
-  }
-
-  return (
-    <div id="Main" className={styles.root}>
-      <KeyboardShortcutRoot>
-        <div className="flexContainer" aria-hidden="false">
-          {userContext.features.enableContainerCopy && userContext.apiType === "SQL" ? (
-            <>
-              <ContainerCopyPanel explorer={explorer} />
-              <SidePanel />
-            </>
-          ) : (
-            <DivExplorer explorer={explorer} />
-          )}
-        </div>
-      </KeyboardShortcutRoot>
-    </div>
-  );
-};
-
-const DivExplorer: React.FC<{ explorer: Explorer }> = ({ explorer }) => {
-  const isCarouselOpen = useCarousel((state) => state.shouldOpen);
-  const isCopilotCarouselOpen = useCarousel((state) => state.showCopilotCarousel);
-  useInteractive(MetricScenario.ApplicationLoad);
-
-  return (
-    <div
-      className="flexContainer"
-      style={{
-        flex: 1,
-        display: "flex",
-        flexDirection: "column",
-        backgroundColor: "var(--colorNeutralBackground1)",
-        color: "var(--colorNeutralForeground1)",
-      }}
-      aria-hidden="false"
-      data-test="DataExplorerRoot"
-    >
-      <div
-        id="divExplorer"
-        className="flexContainer hideOverflows"
-        style={{
-          flex: 1,
-          display: "flex",
-          flexDirection: "column",
-          backgroundColor: "var(--colorNeutralBackground1)",
-          color: "var(--colorNeutralForeground1)",
-        }}
-      >
-        <div id="freeTierTeachingBubble"> </div>
-        <CommandBar container={explorer} />
-        <SidebarContainer explorer={explorer} />
-        <div
-          className="dataExplorerErrorConsoleContainer"
-          role="contentinfo"
-          aria-label="Notification console"
-          id="explorerNotificationConsole"
-          style={{
-            backgroundColor: "var(--colorNeutralBackground1)",
-            color: "var(--colorNeutralForeground1)",
-          }}
-        >
-          <NotificationConsole />
-        </div>
-      </div>
-      <SidePanel />
-      <Dialog />
-      {<QuickstartCarousel isOpen={isCarouselOpen} />}
-      {<SQLQuickstartTutorial />}
-      {<MongoQuickstartTutorial />}
-      {<QueryCopilotCarousel isOpen={isCopilotCarouselOpen} explorer={explorer} />}
-    </div>
-  );
-};
-
-const Root: React.FC = () => {
-  // Use React state to track isDarkMode and subscribe to changes
-  const [isDarkMode, setIsDarkMode] = React.useState(useThemeStore.getState().isDarkMode);
-  const currentTheme = isDarkMode ? webDarkTheme : webLightTheme;
-
-  // Subscribe to theme changes
-  React.useEffect(() => {
-    return useThemeStore.subscribe((state) => {
-      setIsDarkMode(state.isDarkMode);
-    });
-  }, []);
-
-  return (
-    <ErrorBoundary>
-      <FluentProvider theme={currentTheme}>
-        <App />
-      </FluentProvider>
-    </ErrorBoundary>
-  );
-};
-
 const mainElement = document.getElementById("Main");
 if (mainElement) {
   ReactDOM.render(
@@ -223,24 +60,3 @@ if (mainElement) {
     mainElement,
   );
 }
-
-function LoadingExplorer(): JSX.Element {
-  const styles = useStyles();
-  return (
-    <div className={styles.root}>
-      <div className="splashLoaderContainer">
-        <div className="splashLoaderContentContainer">
-          <p className="connectExplorerContent">
-            <img src={hdeConnectImage} alt="Azure Cosmos DB" />
-          </p>
-          <p className="splashLoaderTitle" id="explorerLoadingStatusTitle">
-            Welcome to Azure Cosmos DB
-          </p>
-          <p className="splashLoaderText" id="explorerLoadingStatusText" role="alert">
-            Connecting...
-          </p>
-        </div>
-      </div>
-    </div>
-  );
-}

src/Metrics/MetricScenarioProvider.tsx

@@ -3,7 +3,7 @@ import MetricScenario from "./MetricEvents";
 import { MetricPhase } from "./ScenarioConfig";
 import { scenarioMonitor } from "./ScenarioMonitor";
 
-interface MetricScenarioContextValue {
+export interface MetricScenarioContextValue {
   startScenario: (scenario: MetricScenario) => void;
   startPhase: (scenario: MetricScenario, phase: MetricPhase) => void;
   completePhase: (scenario: MetricScenario, phase: MetricPhase) => void;

src/Platform/Hosted/Components/AccountSwitcher.tsx

@@ -1,7 +1,7 @@
 // TODO: Renable this rule for the file or turn it off everywhere
 /* eslint-disable react/display-name */
 
-import { DefaultButton, IButtonStyles, IContextualMenuItem, IContextualMenuProps } from "@fluentui/react";
+import { DefaultButton, IButtonStyles, IContextualMenuItem } from "@fluentui/react";
 import * as React from "react";
 import { FunctionComponent, useEffect, useState } from "react";
 import { StyleConstants } from "../../../Common/StyleConstants";
@@ -92,16 +92,14 @@ export const AccountSwitcher: FunctionComponent<Props> = ({ armToken, setDatabas
     },
   ];
 
-  const menuProps: IContextualMenuProps = {
-    directionalHintFixed: true,
-    className: "accountSwitchContextualMenu",
-    items,
-  };
-
   return (
     <DefaultButton
       text={buttonText}
-      menuProps={menuProps}
+      menuProps={{
+        directionalHintFixed: true,
+        className: "accountSwitchContextualMenu",
+        items,
+      }}
       styles={buttonStyles}
       className="accountSwitchButton"
       id="accountSwitchButton"

src/Platform/Hosted/Components/SwitchAccount.tsx

@@ -31,6 +31,9 @@ export const SwitchAccount: FunctionComponent<Props> = ({
       }}
       defaultSelectedKey={selectedAccount?.name}
       placeholder={accounts && accounts.length === 0 ? "No Accounts Found" : "Select an Account"}
+      styles={{
+        callout: "accountSwitchAccountDropdownMenu",
+      }}
     />
   );
 };

src/Platform/Hosted/Components/SwitchSubscription.tsx

@@ -30,6 +30,9 @@ export const SwitchSubscription: FunctionComponent<Props> = ({
       }}
       defaultSelectedKey={selectedSubscription?.subscriptionId}
       placeholder={subscriptions && subscriptions.length === 0 ? "No Subscriptions Found" : "Select a Subscription"}
+      styles={{
+        callout: "accountSwitchSubscriptionDropdownMenu",
+      }}
     />
   );
 };

src/RootComponents/App.test.tsx

@@ -0,0 +1,317 @@
+import { loadTheme } from "@fluentui/react";
+import "@testing-library/jest-dom";
+import { render, screen, waitFor } from "@testing-library/react";
+import React from "react";
+import { updateStyles } from "../Common/StyleConstants";
+import { Platform } from "../ConfigContext";
+import { useConfig } from "../hooks/useConfig";
+import { useKnockoutExplorer } from "../hooks/useKnockoutExplorer";
+import { MetricScenarioContextValue, useMetricScenario } from "../Metrics/MetricScenarioProvider";
+import App from "./App";
+
+const mockUserContext = {
+  features: { enableContainerCopy: false },
+  apiType: "SQL",
+};
+
+jest.mock("@fluentui/react", () => ({
+  loadTheme: jest.fn(),
+  makeStyles: jest.fn(() => () => ({
+    root: "mock-app-root-class",
+  })),
+  MessageBarType: {
+    error: "error",
+    warning: "warning",
+    info: "info",
+    success: "success",
+  },
+  SpinnerSize: {
+    xSmall: "xSmall",
+    small: "small",
+    medium: "medium",
+    large: "large",
+  },
+}));
+
+jest.mock("../Common/StyleConstants", () => ({
+  StyleConstants: {
+    BaseMedium: "#000000",
+    AccentMediumHigh: "#0078d4",
+    AccentMedium: "#106ebe",
+    AccentLight: "#deecf9",
+    AccentAccentExtra: "#0078d4",
+    FabricAccentMediumHigh: "#0078d4",
+    FabricAccentMedium: "#106ebe",
+    FabricAccentLight: "#deecf9",
+    PortalAccentMediumHigh: "#0078d4",
+    PortalAccentMedium: "#106ebe",
+    PortalAccentLight: "#deecf9",
+  },
+  updateStyles: jest.fn(),
+}));
+
+jest.mock("./LoadingExplorer", () => {
+  const MockLoadingExplorer = () => {
+    return <div data-testid="mock-loading-explorer">Loading Explorer</div>;
+  };
+  MockLoadingExplorer.displayName = "MockLoadingExplorer";
+  return MockLoadingExplorer;
+});
+
+jest.mock("./ExplorerContainer", () => {
+  const MockExplorerContainer = ({ explorer }: { explorer: unknown }) => {
+    return (
+      <div data-testid="mock-explorer-container">Explorer Container - {explorer ? "with explorer" : "no explorer"}</div>
+    );
+  };
+  MockExplorerContainer.displayName = "MockExplorerContainer";
+  return MockExplorerContainer;
+});
+
+jest.mock("../Explorer/ContainerCopy/ContainerCopyPanel", () => {
+  const MockContainerCopyPanel = ({ explorer }: { explorer: unknown }) => {
+    return (
+      <div data-testid="mock-container-copy-panel">
+        Container Copy Panel - {explorer ? "with explorer" : "no explorer"}
+      </div>
+    );
+  };
+  MockContainerCopyPanel.displayName = "MockContainerCopyPanel";
+  return MockContainerCopyPanel;
+});
+
+jest.mock("../KeyboardShortcuts", () => ({
+  KeyboardShortcutRoot: ({ children }: { children: React.ReactNode }) => (
+    <div data-testid="mock-keyboard-shortcut-root">{children}</div>
+  ),
+}));
+
+jest.mock("../UserContext", () => ({
+  get userContext() {
+    return mockUserContext;
+  },
+}));
+
+const mockConfig = {
+  platform: Platform.Portal,
+};
+
+const mockExplorer = {
+  id: "test-explorer",
+  name: "Test Explorer",
+};
+
+jest.mock("../hooks/useConfig", () => ({
+  useConfig: jest.fn(() => mockConfig),
+}));
+
+jest.mock("../hooks/useKnockoutExplorer", () => ({
+  useKnockoutExplorer: jest.fn(),
+}));
+
+jest.mock("../Metrics/MetricScenarioProvider", () => ({
+  useMetricScenario: jest.fn(() => ({
+    startScenario: jest.fn(),
+    completePhase: jest.fn(),
+  })),
+}));
+
+jest.mock("../Metrics/MetricEvents", () => ({
+  __esModule: true,
+  default: {
+    ApplicationLoad: "ApplicationLoad",
+  },
+}));
+
+jest.mock("../Metrics/ScenarioConfig", () => ({
+  ApplicationMetricPhase: {
+    ExplorerInitialized: "ExplorerInitialized",
+  },
+  CommonMetricPhase: {
+    Interactive: "Interactive",
+  },
+}));
+
+jest.mock("../Platform/Fabric/FabricTheme", () => ({
+  appThemeFabric: { name: "fabric-theme" },
+}));
+
+describe("App", () => {
+
+  afterEach(() => {
+    jest.clearAllMocks();
+    mockUserContext.features = { enableContainerCopy: false };
+    mockUserContext.apiType = "SQL";
+  });
+  let mockStartScenario: jest.Mock;
+  let mockCompletePhase: jest.Mock;
+  let mockUseKnockoutExplorer: jest.Mock;
+  let mockUseConfig: jest.Mock;
+  let mockLoadTheme: jest.Mock;
+  let mockUpdateStyles: jest.Mock;
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+
+    mockStartScenario = jest.fn();
+    mockCompletePhase = jest.fn();
+
+    mockUseKnockoutExplorer = jest.mocked(useKnockoutExplorer);
+    mockUseConfig = jest.mocked(useConfig);
+    mockLoadTheme = jest.mocked(loadTheme);
+    mockUpdateStyles = jest.mocked(updateStyles);
+    
+    const mockUseMetricScenario = jest.mocked(useMetricScenario);
+    mockUseMetricScenario.mockReturnValue({
+        startScenario: mockStartScenario,
+        completePhase: mockCompletePhase
+    } as unknown as MetricScenarioContextValue);
+
+    mockUseConfig.mockReturnValue(mockConfig);
+    mockUseKnockoutExplorer.mockReturnValue(null);
+  });
+
+  test("should render loading explorer when explorer is not ready", () => {
+    mockUseKnockoutExplorer.mockReturnValue(null);
+
+    render(<App />);
+
+    expect(screen.getByTestId("mock-loading-explorer")).toBeInTheDocument();
+    expect(screen.queryByTestId("mock-explorer-container")).not.toBeInTheDocument();
+  });
+
+  test("should render explorer container when explorer is ready", () => {
+    mockUseKnockoutExplorer.mockReturnValue(mockExplorer);
+
+    render(<App />);
+
+    expect(screen.getByTestId("mock-explorer-container")).toBeInTheDocument();
+    expect(screen.queryByTestId("mock-loading-explorer")).not.toBeInTheDocument();
+  });
+
+  test("should start metric scenario on mount", () => {
+    render(<App />);
+
+    expect(mockStartScenario).toHaveBeenCalledWith("ApplicationLoad");
+    expect(mockStartScenario).toHaveBeenCalledTimes(1);
+  });
+
+  test("should complete metric phase when explorer is initialized", async () => {
+    const { rerender } = render(<App />);
+
+    expect(mockCompletePhase).not.toHaveBeenCalled();
+
+    mockUseKnockoutExplorer.mockReturnValue(mockExplorer);
+    rerender(<App />);
+
+    await waitFor(() => {
+      expect(mockCompletePhase).toHaveBeenCalledWith("ApplicationLoad", "ExplorerInitialized");
+    });
+  });
+
+  test("should load fabric theme when platform is Fabric", () => {
+    const fabricConfig = { platform: Platform.Fabric };
+    mockUseConfig.mockReturnValue(fabricConfig);
+    mockUseKnockoutExplorer.mockReturnValue(mockExplorer);
+
+    render(<App />);
+
+    expect(mockLoadTheme).toHaveBeenCalledWith({ name: "fabric-theme" });
+  });
+
+  test("should not load fabric theme when platform is not Fabric", () => {
+    const portalConfig = { platform: Platform.Portal };
+    mockUseConfig.mockReturnValue(portalConfig);
+
+    render(<App />);
+
+    expect(mockLoadTheme).not.toHaveBeenCalled();
+  });
+
+  test("should always call updateStyles", () => {
+    render(<App />);
+
+    expect(mockUpdateStyles).toHaveBeenCalled();
+  });
+
+  test("should render container copy panel when container copy is enabled and API is SQL", () => {
+    mockUserContext.features = { enableContainerCopy: true };
+    mockUserContext.apiType = "SQL";
+    
+    mockUseKnockoutExplorer.mockReturnValue(mockExplorer);
+
+    render(<App />);
+
+    expect(screen.getByTestId("mock-container-copy-panel")).toBeInTheDocument();
+    expect(screen.queryByTestId("mock-explorer-container")).not.toBeInTheDocument();
+  });
+
+  test("should render explorer container when container copy is disabled", () => {
+    mockUserContext.features = { enableContainerCopy: false };
+    mockUserContext.apiType = "SQL";
+    
+    mockUseKnockoutExplorer.mockReturnValue(mockExplorer);
+
+    render(<App />);
+
+    expect(screen.getByTestId("mock-explorer-container")).toBeInTheDocument();
+    expect(screen.queryByTestId("mock-container-copy-panel")).not.toBeInTheDocument();
+  });
+
+  test("should render explorer container when API is not SQL", () => {
+    mockUserContext.features = { enableContainerCopy: true };
+    mockUserContext.apiType = "MongoDB";
+    
+    mockUseKnockoutExplorer.mockReturnValue(mockExplorer);
+
+    render(<App />);
+
+    expect(screen.getByTestId("mock-explorer-container")).toBeInTheDocument();
+    expect(screen.queryByTestId("mock-container-copy-panel")).not.toBeInTheDocument();
+  });
+
+  test("should have correct DOM structure", () => {
+    mockUseKnockoutExplorer.mockReturnValue(mockExplorer);
+
+    const { container } = render(<App />);
+
+    const mainDiv = container.querySelector("#Main");
+    expect(mainDiv).toBeInTheDocument();
+    expect(mainDiv).toHaveClass("mock-app-root-class");
+
+    expect(screen.getByTestId("mock-keyboard-shortcut-root")).toBeInTheDocument();
+
+    const flexContainer = container.querySelector(".flexContainer");
+    expect(flexContainer).toBeInTheDocument();
+    expect(flexContainer).toHaveAttribute("aria-hidden", "false");
+  });
+
+  test("should handle config changes for Fabric platform", () => {
+    const { rerender } = render(<App />);
+
+    const fabricConfig = { platform: Platform.Fabric };
+    mockUseConfig.mockReturnValue(fabricConfig);
+
+    rerender(<App />);
+
+    expect(mockLoadTheme).toHaveBeenCalledWith({ name: "fabric-theme" });
+  });
+
+  test("should pass explorer to child components", () => {
+    mockUseKnockoutExplorer.mockReturnValue(mockExplorer);
+
+    render(<App />);
+
+    expect(screen.getByText("Explorer Container - with explorer")).toBeInTheDocument();
+  });
+
+  test("should handle null config gracefully", () => {
+    mockUseConfig.mockReturnValue(null);
+    mockUseKnockoutExplorer.mockReturnValue(mockExplorer);
+
+    expect(() => render(<App />)).not.toThrow();
+
+    expect(mockLoadTheme).not.toHaveBeenCalled();
+    expect(mockUpdateStyles).toHaveBeenCalled();
+  });
+});

src/RootComponents/App.tsx

@@ -0,0 +1,73 @@
+import { loadTheme, makeStyles } from "@fluentui/react";
+import React from "react";
+import * as StyleConstants from "../Common/StyleConstants";
+import { Platform } from "../ConfigContext";
+import ContainerCopyPanel from "../Explorer/ContainerCopy/ContainerCopyPanel";
+import { useConfig } from "../hooks/useConfig";
+import { useKnockoutExplorer } from "../hooks/useKnockoutExplorer";
+import { KeyboardShortcutRoot } from "../KeyboardShortcuts";
+import MetricScenario from "../Metrics/MetricEvents";
+import { useMetricScenario } from "../Metrics/MetricScenarioProvider";
+import { ApplicationMetricPhase } from "../Metrics/ScenarioConfig";
+import { appThemeFabric } from "../Platform/Fabric/FabricTheme";
+import { userContext } from "../UserContext";
+import ExplorerContainer from "./ExplorerContainer";
+import LoadingExplorer from "./LoadingExplorer";
+
+const useStyles = makeStyles({
+  root: {
+    height: "100vh",
+    width: "100vw",
+    backgroundColor: "var(--colorNeutralBackground1)",
+    color: "var(--colorNeutralForeground1)",
+  },
+});
+
+const App = (): JSX.Element => {
+  const config = useConfig();
+  const styles = useStyles();
+  // Load Fabric theme and styles only once when platform is Fabric
+  React.useEffect(() => {
+    if (config?.platform === Platform.Fabric) {
+      loadTheme(appThemeFabric);
+      import("../../less/documentDBFabric.less");
+    }
+    StyleConstants.updateStyles();
+  }, [config?.platform]);
+
+  const explorer = useKnockoutExplorer(config?.platform);
+
+  // Scenario-based health tracking: start ApplicationLoad and complete phases.
+  const { startScenario, completePhase } = useMetricScenario();
+  React.useEffect(() => {
+    startScenario(MetricScenario.ApplicationLoad);
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  React.useEffect(() => {
+    if (explorer) {
+      completePhase(MetricScenario.ApplicationLoad, ApplicationMetricPhase.ExplorerInitialized);
+    }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [explorer]);
+
+  if (!explorer) {
+    return <LoadingExplorer />;
+  }
+
+  return (
+    <div id="Main" className={styles.root}>
+      <KeyboardShortcutRoot>
+        <div className="flexContainer" aria-hidden="false">
+          {userContext.features.enableContainerCopy && userContext.apiType === "SQL" ? (
+            <ContainerCopyPanel explorer={explorer} />
+          ) : (
+            <ExplorerContainer explorer={explorer} />
+          )}
+        </div>
+      </KeyboardShortcutRoot>
+    </div>
+  );
+};
+
+export default App;

src/RootComponents/ExplorerContainer.test.tsx

@@ -0,0 +1,183 @@
+import "@testing-library/jest-dom";
+import { render, screen } from "@testing-library/react";
+import React from "react";
+import Explorer from "../Explorer/Explorer";
+import { useCarousel } from "../hooks/useCarousel";
+import { useInteractive } from "../Metrics/useMetricPhases";
+import ExplorerContainer from "./ExplorerContainer";
+
+jest.mock("../Explorer/Controls/Dialog", () => ({
+  Dialog: () => <div data-testid="mock-dialog">Dialog</div>,
+}));
+
+jest.mock("../Explorer/Menus/CommandBar/CommandBarComponentAdapter", () => ({
+  CommandBar: ({ container }: { container: Explorer }) => (
+    <div data-testid="mock-command-bar">CommandBar - {container ? "with explorer" : "no explorer"}</div>
+  ),
+}));
+
+jest.mock("../Explorer/Menus/NotificationConsole/NotificationConsoleComponent", () => ({
+  NotificationConsole: () => <div data-testid="mock-notification-console">NotificationConsole</div>,
+}));
+
+jest.mock("../Explorer/Panes/PanelContainerComponent", () => ({
+  SidePanel: () => <div data-testid="mock-side-panel">SidePanel</div>,
+}));
+
+jest.mock("../Explorer/QueryCopilot/CopilotCarousel", () => ({
+  QueryCopilotCarousel: ({ isOpen, explorer }: { isOpen: boolean; explorer: Explorer }) => (
+    <div data-testid="mock-copilot-carousel">
+      CopilotCarousel - {isOpen ? "open" : "closed"} - {explorer ? "with explorer" : "no explorer"}
+    </div>
+  ),
+}));
+
+jest.mock("../Explorer/Quickstart/QuickstartCarousel", () => ({
+  QuickstartCarousel: ({ isOpen }: { isOpen: boolean }) => (
+    <div data-testid="mock-quickstart-carousel">QuickstartCarousel - {isOpen ? "open" : "closed"}</div>
+  ),
+}));
+
+jest.mock("../Explorer/Quickstart/Tutorials/MongoQuickstartTutorial", () => ({
+  MongoQuickstartTutorial: () => <div data-testid="mock-mongo-tutorial">MongoQuickstartTutorial</div>,
+}));
+
+jest.mock("../Explorer/Quickstart/Tutorials/SQLQuickstartTutorial", () => ({
+  SQLQuickstartTutorial: () => <div data-testid="mock-sql-tutorial">SQLQuickstartTutorial</div>,
+}));
+
+jest.mock("../Explorer/Sidebar", () => ({
+  SidebarContainer: ({ explorer }: { explorer: Explorer }) => (
+    <div data-testid="mock-sidebar-container">SidebarContainer - {explorer ? "with explorer" : "no explorer"}</div>
+  ),
+}));
+
+jest.mock("../hooks/useCarousel", () => ({
+  useCarousel: jest.fn((selector) => {
+    if (selector.toString().includes("shouldOpen")) {
+      return true;
+    }
+    if (selector.toString().includes("showCopilotCarousel")) {
+      return false;
+    }
+    return false;
+  }),
+}));
+
+jest.mock("../Metrics/useMetricPhases", () => ({
+  useInteractive: jest.fn(),
+}));
+
+jest.mock("../Metrics/MetricEvents", () => ({
+  __esModule: true,
+  default: {
+    ApplicationLoad: "ApplicationLoad",
+  },
+}));
+
+describe("ExplorerContainer", () => {
+  let mockExplorer: Explorer;
+
+  beforeEach(() => {
+    mockExplorer = {
+      id: "test-explorer",
+      name: "Test Explorer",
+    } as unknown as Explorer;
+
+    jest.clearAllMocks();
+  });
+
+  test("should render explorer container with all components", () => {
+    const { container } = render(<ExplorerContainer explorer={mockExplorer} />);
+
+    const mainContainer = container.querySelector('[data-test="DataExplorerRoot"]');
+    expect(mainContainer).toBeInTheDocument();
+    expect(mainContainer).toHaveClass("flexContainer");
+
+    expect(screen.getByTestId("mock-command-bar")).toBeInTheDocument();
+    expect(screen.getByTestId("mock-sidebar-container")).toBeInTheDocument();
+    expect(screen.getByTestId("mock-notification-console")).toBeInTheDocument();
+    expect(screen.getByTestId("mock-side-panel")).toBeInTheDocument();
+    expect(screen.getByTestId("mock-dialog")).toBeInTheDocument();
+    expect(screen.getByTestId("mock-quickstart-carousel")).toBeInTheDocument();
+    expect(screen.getByTestId("mock-sql-tutorial")).toBeInTheDocument();
+    expect(screen.getByTestId("mock-mongo-tutorial")).toBeInTheDocument();
+    expect(screen.getByTestId("mock-copilot-carousel")).toBeInTheDocument();
+  });
+
+  test("should pass explorer to components that need it", () => {
+    render(<ExplorerContainer explorer={mockExplorer} />);
+
+    expect(screen.getByText("CommandBar - with explorer")).toBeInTheDocument();
+    expect(screen.getByText("SidebarContainer - with explorer")).toBeInTheDocument();
+    expect(screen.getByText("CopilotCarousel - closed - with explorer")).toBeInTheDocument();
+  });
+
+  test("should have correct DOM structure", () => {
+    const { container } = render(<ExplorerContainer explorer={mockExplorer} />);
+
+    const mainContainer = container.querySelector('[data-test="DataExplorerRoot"]');
+    expect(mainContainer).toBeInTheDocument();
+    expect(mainContainer).toHaveAttribute("aria-hidden", "false");
+
+    const divExplorer = container.querySelector("#divExplorer");
+    expect(divExplorer).toBeInTheDocument();
+    expect(divExplorer).toHaveClass("flexContainer", "hideOverflows");
+
+    const freeTierBubble = container.querySelector("#freeTierTeachingBubble");
+    expect(freeTierBubble).toBeInTheDocument();
+
+    const notificationContainer = container.querySelector("#explorerNotificationConsole");
+    expect(notificationContainer).toBeInTheDocument();
+    expect(notificationContainer).toHaveClass("dataExplorerErrorConsoleContainer");
+    expect(notificationContainer).toHaveAttribute("role", "contentinfo");
+    expect(notificationContainer).toHaveAttribute("aria-label", "Notification console");
+  });
+
+  test("should apply correct inline styles", () => {
+    const { container } = render(<ExplorerContainer explorer={mockExplorer} />);
+
+    const mainContainer = container.querySelector('[data-test="DataExplorerRoot"]');
+    expect(mainContainer).toHaveStyle({
+      flex: "1",
+      display: "flex",
+      flexDirection: "column",
+      backgroundColor: "var(--colorNeutralBackground1)",
+      color: "var(--colorNeutralForeground1)",
+    });
+
+    const divExplorer = container.querySelector("#divExplorer");
+    expect(divExplorer).toHaveStyle({
+      flex: "1",
+      display: "flex",
+      flexDirection: "column",
+    });
+  });
+
+  test("should handle carousel states correctly", () => {
+    const mockUseCarousel = jest.mocked(useCarousel);
+
+    mockUseCarousel.mockImplementation((selector: { toString: () => string | string[] }) => {
+      if (selector.toString().includes("shouldOpen")) {
+        return false;
+      }
+      if (selector.toString().includes("showCopilotCarousel")) {
+        return true;
+      }
+      return false;
+    });
+
+    render(<ExplorerContainer explorer={mockExplorer} />);
+
+    expect(screen.getByText("QuickstartCarousel - closed")).toBeInTheDocument();
+    expect(screen.getByText("CopilotCarousel - open - with explorer")).toBeInTheDocument();
+  });
+
+  test("should call useInteractive hook with correct metric", () => {
+    const mockUseInteractive = jest.mocked(useInteractive);
+
+    render(<ExplorerContainer explorer={mockExplorer} />);
+
+    expect(mockUseInteractive).toHaveBeenCalledWith("ApplicationLoad");
+  });
+});

src/RootComponents/ExplorerContainer.tsx

@@ -0,0 +1,71 @@
+import React from "react";
+import { Dialog } from "../Explorer/Controls/Dialog";
+import Explorer from "../Explorer/Explorer";
+import { CommandBar } from "../Explorer/Menus/CommandBar/CommandBarComponentAdapter";
+import { NotificationConsole } from "../Explorer/Menus/NotificationConsole/NotificationConsoleComponent";
+import { SidePanel } from "../Explorer/Panes/PanelContainerComponent";
+import { QueryCopilotCarousel } from "../Explorer/QueryCopilot/CopilotCarousel";
+import { QuickstartCarousel } from "../Explorer/Quickstart/QuickstartCarousel";
+import { MongoQuickstartTutorial } from "../Explorer/Quickstart/Tutorials/MongoQuickstartTutorial";
+import { SQLQuickstartTutorial } from "../Explorer/Quickstart/Tutorials/SQLQuickstartTutorial";
+import { SidebarContainer } from "../Explorer/Sidebar";
+import { useCarousel } from "../hooks/useCarousel";
+import MetricScenario from "../Metrics/MetricEvents";
+import { useInteractive } from "../Metrics/useMetricPhases";
+
+const ExplorerContainer: React.FC<{ explorer: Explorer }> = ({ explorer }) => {
+  const isCarouselOpen = useCarousel((state) => state.shouldOpen);
+  const isCopilotCarouselOpen = useCarousel((state) => state.showCopilotCarousel);
+  useInteractive(MetricScenario.ApplicationLoad);
+
+  return (
+    <div
+      className="flexContainer"
+      style={{
+        flex: 1,
+        display: "flex",
+        flexDirection: "column",
+        backgroundColor: "var(--colorNeutralBackground1)",
+        color: "var(--colorNeutralForeground1)",
+      }}
+      aria-hidden="false"
+      data-test="DataExplorerRoot"
+    >
+      <div
+        id="divExplorer"
+        className="flexContainer hideOverflows"
+        style={{
+          flex: 1,
+          display: "flex",
+          flexDirection: "column",
+          backgroundColor: "var(--colorNeutralBackground1)",
+          color: "var(--colorNeutralForeground1)",
+        }}
+      >
+        <div id="freeTierTeachingBubble"> </div>
+        <CommandBar container={explorer} />
+        <SidebarContainer explorer={explorer} />
+        <div
+          className="dataExplorerErrorConsoleContainer"
+          role="contentinfo"
+          aria-label="Notification console"
+          id="explorerNotificationConsole"
+          style={{
+            backgroundColor: "var(--colorNeutralBackground1)",
+            color: "var(--colorNeutralForeground1)",
+          }}
+        >
+          <NotificationConsole />
+        </div>
+      </div>
+      <SidePanel />
+      <Dialog />
+      {<QuickstartCarousel isOpen={isCarouselOpen} />}
+      {<SQLQuickstartTutorial />}
+      {<MongoQuickstartTutorial />}
+      {<QueryCopilotCarousel isOpen={isCopilotCarouselOpen} explorer={explorer} />}
+    </div>
+  );
+};
+
+export default ExplorerContainer;

src/RootComponents/LoadingExplorer.test.tsx

@@ -0,0 +1,71 @@
+import "@testing-library/jest-dom";
+import { render, screen } from "@testing-library/react";
+import React from "react";
+import LoadingExplorer from "./LoadingExplorer";
+
+jest.mock("../../images/HdeConnectCosmosDB.svg", () => "test-hde-connect-image.svg");
+
+jest.mock("@fluentui/react-components", () => ({
+  makeStyles: jest.fn(() => () => ({
+    root: "mock-root-class",
+  })),
+}));
+
+describe("LoadingExplorer", () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  test("should render loading explorer component", () => {
+    render(<LoadingExplorer />);
+
+    const container = screen.getByRole("alert");
+    expect(container).toBeInTheDocument();
+    expect(container).toHaveTextContent("Connecting...");
+  });
+
+  test("should display welcome title", () => {
+    render(<LoadingExplorer />);
+
+    const title = screen.getByText("Welcome to Azure Cosmos DB");
+    expect(title).toBeInTheDocument();
+    expect(title).toHaveAttribute("id", "explorerLoadingStatusTitle");
+  });
+
+  test("should display connecting status text", () => {
+    render(<LoadingExplorer />);
+
+    const statusText = screen.getByText("Connecting...");
+    expect(statusText).toBeInTheDocument();
+    expect(statusText).toHaveAttribute("id", "explorerLoadingStatusText");
+    expect(statusText).toHaveAttribute("role", "alert");
+  });
+
+  test("should render Azure Cosmos DB image", () => {
+    render(<LoadingExplorer />);
+
+    const image = screen.getByAltText("Azure Cosmos DB");
+    expect(image).toBeInTheDocument();
+    expect(image).toHaveAttribute("src", "test-hde-connect-image.svg");
+  });
+
+  test("should have correct class structure", () => {
+    render(<LoadingExplorer />);
+
+    const splashContainer = document.querySelector(".splashLoaderContainer");
+    expect(splashContainer).toBeInTheDocument();
+
+    const contentContainer = document.querySelector(".splashLoaderContentContainer");
+    expect(contentContainer).toBeInTheDocument();
+
+    const connectContent = document.querySelector(".connectExplorerContent");
+    expect(connectContent).toBeInTheDocument();
+  });
+
+  test("should apply CSS classes correctly", () => {
+    const { container } = render(<LoadingExplorer />);
+
+    const rootDiv = container.firstChild as HTMLElement;
+    expect(rootDiv).toHaveClass("mock-root-class");
+  });
+});

src/RootComponents/LoadingExplorer.tsx

@@ -0,0 +1,36 @@
+import { makeStyles } from "@fluentui/react-components";
+import React from "react";
+import hdeConnectImage from "../../images/HdeConnectCosmosDB.svg";
+
+const useStyles = makeStyles({
+  root: {
+    height: "100vh",
+    width: "100vw",
+    backgroundColor: "var(--colorNeutralBackground1)",
+    color: "var(--colorNeutralForeground1)",
+  },
+});
+
+function LoadingExplorer(): JSX.Element {
+  const styles = useStyles();
+
+  return (
+    <div className={styles.root}>
+      <div className="splashLoaderContainer">
+        <div className="splashLoaderContentContainer">
+          <p className="connectExplorerContent">
+            <img src={hdeConnectImage} alt="Azure Cosmos DB" />
+          </p>
+          <p className="splashLoaderTitle" id="explorerLoadingStatusTitle">
+            Welcome to Azure Cosmos DB
+          </p>
+          <p className="splashLoaderText" id="explorerLoadingStatusText" role="alert">
+            Connecting...
+          </p>
+        </div>
+      </div>
+    </div>
+  );
+}
+
+export default LoadingExplorer;

src/RootComponents/Root.test.tsx

@@ -0,0 +1,107 @@
+import "@testing-library/jest-dom";
+import { render, screen } from "@testing-library/react";
+import React from "react";
+import Root from "./Root";
+
+jest.mock("../Explorer/ErrorBoundary", () => ({
+  ErrorBoundary: ({ children }: { children: React.ReactNode }) => (
+    <div data-testid="mock-error-boundary">{children}</div>
+  ),
+}));
+
+jest.mock("@fluentui/react-components", () => ({
+  FluentProvider: ({ children, theme }: { children: React.ReactNode; theme: { colorNeutralBackground1: string } }) => (
+    <div
+      data-testid="mock-fluent-provider"
+      data-theme={theme.colorNeutralBackground1 === "dark" ? "webDarkTheme" : "webLightTheme"}
+    >
+      {children}
+    </div>
+  ),
+  webLightTheme: { colorNeutralBackground1: "light" },
+  webDarkTheme: { colorNeutralBackground1: "dark" },
+}));
+
+jest.mock("./App", () => ({
+  __esModule: true,
+  default: () => <div data-testid="mock-app">App</div>,
+}));
+
+const createMockStore = (isDarkMode: boolean = false) => ({
+  getState: jest.fn(() => ({ isDarkMode })),
+  subscribe: jest.fn(() => jest.fn()),
+});
+
+const mockThemeStore = createMockStore(false);
+
+jest.mock("../hooks/useTheme", () => ({
+  get useThemeStore() {
+    return mockThemeStore;
+  },
+}));
+
+describe("Root", () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  test("should render Root component with all child components", () => {
+    render(<Root />);
+
+    expect(screen.getByTestId("mock-error-boundary")).toBeInTheDocument();
+    expect(screen.getByTestId("mock-fluent-provider")).toBeInTheDocument();
+    expect(screen.getByTestId("mock-app")).toBeInTheDocument();
+  });
+
+  test("should have correct component hierarchy", () => {
+    render(<Root />);
+
+    const errorBoundary = screen.getByTestId("mock-error-boundary");
+    const fluentProvider = screen.getByTestId("mock-fluent-provider");
+    const app = screen.getByTestId("mock-app");
+
+    expect(errorBoundary).toContainElement(fluentProvider);
+    expect(fluentProvider).toContainElement(app);
+  });
+
+  test("should subscribe to theme changes on mount", () => {
+    render(<Root />);
+
+    expect(mockThemeStore.subscribe).toHaveBeenCalled();
+    expect(mockThemeStore.subscribe).toHaveBeenCalledWith(expect.any(Function));
+  });
+
+  test("should get initial theme state", () => {
+    render(<Root />);
+
+    expect(mockThemeStore.getState).toHaveBeenCalled();
+  });
+
+  test("should handle component unmounting", () => {
+    const mockUnsubscribe = jest.fn();
+    mockThemeStore.subscribe.mockReturnValue(mockUnsubscribe);
+
+    const { unmount } = render(<Root />);
+
+    unmount();
+
+    expect(mockUnsubscribe).toHaveBeenCalled();
+  });
+
+  test("should call getState to initialize theme", () => {
+    render(<Root />);
+
+    expect(mockThemeStore.getState).toHaveBeenCalledTimes(1);
+  });
+
+  test("should handle theme subscription properly", () => {
+    render(<Root />);
+
+    expect(mockThemeStore.subscribe).toHaveBeenCalledTimes(1);
+    expect(mockThemeStore.getState).toHaveBeenCalled();
+  });
+
+  test("should render without errors", () => {
+    expect(() => render(<Root />)).not.toThrow();
+  });
+});

src/RootComponents/Root.tsx

@@ -0,0 +1,28 @@
+import { FluentProvider, webDarkTheme, webLightTheme } from "@fluentui/react-components";
+import React from "react";
+import { ErrorBoundary } from "../Explorer/ErrorBoundary";
+import { useThemeStore } from "../hooks/useTheme";
+import App from "./App";
+
+const Root: React.FC = () => {
+  // Use React state to track isDarkMode and subscribe to changes
+  const [isDarkMode, setIsDarkMode] = React.useState(useThemeStore.getState().isDarkMode);
+  const currentTheme = isDarkMode ? webDarkTheme : webLightTheme;
+
+  // Subscribe to theme changes
+  React.useEffect(() => {
+    return useThemeStore.subscribe((state) => {
+      setIsDarkMode(state.isDarkMode);
+    });
+  }, []);
+
+  return (
+    <ErrorBoundary>
+      <FluentProvider theme={currentTheme}>
+        <App />
+      </FluentProvider>
+    </ErrorBoundary>
+  );
+};
+
+export default Root;

test/fx.ts

@@ -470,15 +470,6 @@ export class DataExplorer {
     return this.frame.getByTestId("notification-console/header-status");
   }
 
-  async getDropdownItemByName(name: string, ariaLabel?: string): Promise<Locator> {
-    const dropdownItemsWrapper = this.frame.locator("div.ms-Dropdown-items");
-    if (ariaLabel) {
-      expect(await dropdownItemsWrapper.getAttribute("aria-label")).toEqual(ariaLabel);
-    }
-    const containerDropdownItems = dropdownItemsWrapper.locator("button.ms-Dropdown-item[role='option']");
-    return containerDropdownItems.filter({ hasText: name });
-  }
-
   /** Waits for the Data Explorer app to load */
   static async waitForExplorer(page: Page) {
     const iframeElement = await page.getByTestId("DataExplorerFrame").elementHandle();

test/sql/query.spec.ts

@@ -9,7 +9,7 @@ let queryTab: QueryTab = null!;
 let queryEditor: Editor = null!;
 
 test.beforeAll("Create Test Database", async () => {
-  context = await createTestSQLContainer({ includeTestData: true });
+  context = await createTestSQLContainer(true);
 });
 
 test.beforeEach("Open new query tab", async ({ page }) => {

test/sql/scaleAndSettings/changePartitionKey.spec.ts

@@ -1,98 +0,0 @@
-import { expect, Page, test } from "@playwright/test";
-import { DataExplorer, TestAccount } from "../../fx";
-import { createTestSQLContainer, TestContainerContext } from "../../testData";
-
-test.describe("Change Partition Key", () => {
-  let pageInstance: Page;
-  let context: TestContainerContext = null!;
-  let explorer: DataExplorer = null!;
-  const newPartitionKeyPath = "/newPartitionKey";
-  const newContainerId = "testcontainer_1";
-
-  test.beforeAll("Create Test Database", async () => {
-    context = await createTestSQLContainer();
-  });
-
-  test.beforeEach("Open container settings", async ({ page }) => {
-    pageInstance = page;
-    explorer = await DataExplorer.open(page, TestAccount.SQL);
-
-    // Click Scale & Settings and open Partition Key tab
-    await explorer.openScaleAndSettings(context);
-    const PartitionKeyTab = explorer.frame.getByTestId("settings-tab-header/PartitionKeyTab");
-    await PartitionKeyTab.click();
-  });
-
-  test.afterAll("Delete Test Database", async () => {
-    await context?.dispose();
-  });
-
-  test("Change partition key path", async () => {
-    await expect(explorer.frame.getByText("/partitionKey")).toBeVisible();
-    await expect(explorer.frame.getByText("Change partition key")).toBeVisible();
-    await expect(explorer.frame.getByText(/To safeguard the integrity of/)).toBeVisible();
-    await expect(explorer.frame.getByText(/To change the partition key/)).toBeVisible();
-
-    const changePartitionKeyButton = explorer.frame.getByTestId("change-partition-key-button");
-    expect(changePartitionKeyButton).toBeVisible();
-    await changePartitionKeyButton.click();
-
-    // Fill out new partition key form in the panel
-    const changePkPanel = explorer.frame.getByTestId(`Panel:Change partition key`);
-    await expect(changePkPanel.getByText(context.database.id)).toBeVisible();
-    await expect(explorer.frame.getByRole("heading", { name: "Change partition key" })).toBeVisible();
-    await expect(explorer.frame.getByText(/When changing a container/)).toBeVisible();
-
-    // Try to switch to new container
-    await expect(changePkPanel.getByText("New container")).toBeVisible();
-    await expect(changePkPanel.getByText("Existing container")).toBeVisible();
-    await expect(changePkPanel.getByTestId("new-container-id-input")).toBeVisible();
-
-    changePkPanel.getByTestId("new-container-id-input").fill(newContainerId);
-    await expect(changePkPanel.getByTestId("new-container-partition-key-input")).toBeVisible();
-    changePkPanel.getByTestId("new-container-partition-key-input").fill(newPartitionKeyPath);
-
-    await expect(changePkPanel.getByTestId("add-sub-partition-key-button")).toBeVisible();
-    changePkPanel.getByTestId("add-sub-partition-key-button").click();
-    await expect(changePkPanel.getByTestId("new-container-sub-partition-key-input-0")).toBeVisible();
-    await expect(changePkPanel.getByTestId("remove-sub-partition-key-button-0")).toBeVisible();
-    await expect(changePkPanel.getByTestId("hierarchical-partitioning-info-text")).toBeVisible();
-    changePkPanel.getByTestId("new-container-sub-partition-key-input-0").fill("/customerId");
-
-    await changePkPanel.getByTestId("Panel/OkButton").click();
-
-    await pageInstance.waitForLoadState("networkidle");
-    await expect(changePkPanel).not.toBeVisible({ timeout: 60 * 1000 });
-
-    // Verify partition key change job
-    const jobText = explorer.frame.getByText(/Partition key change job/);
-    await expect(jobText).toBeVisible();
-    await expect(explorer.frame.locator(".ms-ProgressIndicator-itemName")).toContainText("Portal_testcontainer_1");
-
-    const jobRow = explorer.frame.locator(".ms-ProgressIndicator-itemDescription");
-    await expect(jobRow.getByText("Completed")).toBeVisible({ timeout: 30 * 1000 });
-
-    const newContainerNode = await explorer.waitForContainerNode(context.database.id, newContainerId);
-    expect(newContainerNode).not.toBeNull();
-
-    // Now try to switch to existing container
-    await changePartitionKeyButton.click();
-    await changePkPanel.getByText("Existing container").click();
-    await changePkPanel.getByLabel("Use existing container").check();
-    await changePkPanel.getByText("Choose an existing container").click();
-
-    const containerDropdownItem = await explorer.getDropdownItemByName(newContainerId, "Existing Containers");
-    await containerDropdownItem.click();
-
-    await changePkPanel.getByTestId("Panel/OkButton").click();
-    await explorer.frame.getByRole("button", { name: "Cancel" }).click();
-
-    // Dismiss overlay if it appears
-    const overlayFrame = explorer.frame.locator("#webpack-dev-server-client-overlay").first();
-    if (await overlayFrame.count()) {
-      await overlayFrame.contentFrame().getByLabel("Dismiss").click();
-    }
-    const cancelledJobRow = explorer.frame.getByTestId("Tab:tab0");
-    await expect(cancelledJobRow.getByText("Cancelled")).toBeVisible({ timeout: 30 * 1000 });
-  });
-});

test/sql/scaleAndSettings/scale.spec.ts

@@ -14,7 +14,7 @@ test.describe("Autoscale and Manual throughput", () => {
   let explorer: DataExplorer = null!;
 
   test.beforeAll("Create Test Database", async () => {
-    context = await createTestSQLContainer({ includeTestData: true });
+    context = await createTestSQLContainer(true);
   });
 
   test.beforeEach("Open container settings", async ({ page }) => {

test/sql/scaleAndSettings/settings.spec.ts

@@ -7,7 +7,7 @@ test.describe("Settings under Scale & Settings", () => {
   let explorer: DataExplorer = null!;
 
   test.beforeAll("Create Test Database", async () => {
-    context = await createTestSQLContainer({ includeTestData: true });
+    context = await createTestSQLContainer(true);
   });
 
   test.beforeEach("Open Settings tab under Scale & Settings", async ({ page }) => {

test/testData.ts

@@ -74,18 +74,8 @@ export class TestContainerContext {
   }
 }
 
-type createTestSqlContainerConfig = {
-  includeTestData?: boolean;
-  partitionKey?: string;
-  databaseName?: string;
-};
-
-export async function createTestSQLContainer({
-  includeTestData = false,
-  partitionKey = "/partitionKey",
-  databaseName = "",
-}: createTestSqlContainerConfig = {}) {
-  const databaseId = databaseName ? databaseName : generateUniqueName("db");
+export async function createTestSQLContainer(includeTestData?: boolean) {
+  const databaseId = generateUniqueName("db");
   const containerId = "testcontainer"; // A unique container name isn't needed because the database is unique
   const credentials = getAzureCLICredentials();
   const adaptedCredentials = new AzureIdentityCredentialAdapter(credentials);
@@ -114,7 +104,7 @@ export async function createTestSQLContainer({
   try {
     const { container } = await database.containers.createIfNotExists({
       id: containerId,
-      partitionKey,
+      partitionKey: "/partitionKey",
     });
     if (includeTestData) {
       const batchCount = TestData.length / 100;