Refactor: Extract root components architecture with comprehensive tests

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/Main.tsx

@@ -2,18 +2,9 @@
 import "./ReactDevTools";
 
 // CSS Dependencies
-import { initializeIcons, loadTheme, useTheme } from "@fluentui/react";
+import { initializeIcons } 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 "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";
@@ -42,175 +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 } from "./Metrics/MetricScenarioProvider";
-import { MetricScenarioProvider, useMetricScenario } from "./Metrics/MetricScenarioProvider";
+import Root from "./RootComponents/Root";
-import { ApplicationMetricPhase } from "./Metrics/ScenarioConfig";
-import { useInteractive } from "./Metrics/useMetricPhases";
-import { appThemeFabric } from "./Platform/Fabric/FabricTheme";
 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} />
-          ) : (
-            <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(
@@ -220,24 +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/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;