Added comprehensive unit test coverage for Container Copy jobs (#2275)

* copy job uts

* unit test coverage

* lint fix

* normalize account dropdown id

src/Common/LoadingOverlay.test.tsx

@@ -0,0 +1,52 @@
+import { render } from "@testing-library/react";
+import React from "react";
+import LoadingOverlay from "./LoadingOverlay";
+
+describe("LoadingOverlay", () => {
+  const defaultProps = {
+    isLoading: true,
+    label: "Loading...",
+  };
+
+  it("should render loading overlay when isLoading is true", () => {
+    const { container } = render(<LoadingOverlay {...defaultProps} />);
+    expect(container.firstChild).toMatchSnapshot();
+  });
+
+  it("should render loading overlay with custom label", () => {
+    const customProps = {
+      isLoading: true,
+      label: "Processing your request...",
+    };
+    const { container } = render(<LoadingOverlay {...customProps} />);
+    expect(container.firstChild).toMatchSnapshot();
+  });
+
+  it("should render loading overlay with empty label", () => {
+    const emptyLabelProps = {
+      isLoading: true,
+      label: "",
+    };
+    const { container } = render(<LoadingOverlay {...emptyLabelProps} />);
+    expect(container.firstChild).toMatchSnapshot();
+  });
+
+  it("should return null when isLoading is false", () => {
+    const notLoadingProps = {
+      isLoading: false,
+      label: "Loading...",
+    };
+    const { container } = render(<LoadingOverlay {...notLoadingProps} />);
+    expect(container.firstChild).toBeNull();
+  });
+
+  it("should handle long labels properly", () => {
+    const longLabelProps = {
+      isLoading: true,
+      label:
+        "This is a very long loading message that might span multiple lines and should still render correctly in the loading overlay component",
+    };
+    const { container } = render(<LoadingOverlay {...longLabelProps} />);
+    expect(container.firstChild).toMatchSnapshot();
+  });
+});

src/Common/__snapshots__/LoadingOverlay.test.tsx.snap

@@ -0,0 +1,73 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`LoadingOverlay should handle long labels properly 1`] = `
+<div
+  class="ms-Overlay root-109"
+>
+  <div
+    class="ms-Spinner root-111"
+  >
+    <div
+      class="ms-Spinner-circle ms-Spinner--large circle-112"
+    />
+    <div
+      class="ms-Spinner-label label-113"
+    >
+      This is a very long loading message that might span multiple lines and should still render correctly in the loading overlay component
+    </div>
+  </div>
+</div>
+`;
+
+exports[`LoadingOverlay should render loading overlay when isLoading is true 1`] = `
+<div
+  class="ms-Overlay root-109"
+>
+  <div
+    class="ms-Spinner root-111"
+  >
+    <div
+      class="ms-Spinner-circle ms-Spinner--large circle-112"
+    />
+    <div
+      class="ms-Spinner-label label-113"
+    >
+      Loading...
+    </div>
+  </div>
+</div>
+`;
+
+exports[`LoadingOverlay should render loading overlay with custom label 1`] = `
+<div
+  class="ms-Overlay root-109"
+>
+  <div
+    class="ms-Spinner root-111"
+  >
+    <div
+      class="ms-Spinner-circle ms-Spinner--large circle-112"
+    />
+    <div
+      class="ms-Spinner-label label-113"
+    >
+      Processing your request...
+    </div>
+  </div>
+</div>
+`;
+
+exports[`LoadingOverlay should render loading overlay with empty label 1`] = `
+<div
+  class="ms-Overlay root-109"
+>
+  <div
+    class="ms-Spinner root-111"
+  >
+    <div
+      class="ms-Spinner-circle ms-Spinner--large circle-112"
+    />
+    
+  </div>
+</div>
+`;