test(tabs): add unit tests

tests/Tabs/Tabs.test.svelte

@@ -0,0 +1,29 @@
+<script lang="ts">
+  import { Tabs, Tab, TabContent } from "carbon-components-svelte";
+
+  export let selected = 0;
+  export let type: "default" | "container" = "default";
+  export let autoWidth = false;
+  export let iconDescription = "Show menu options";
+  export let triggerHref = "#";
+</script>
+
+<Tabs
+  {selected}
+  {type}
+  {autoWidth}
+  {iconDescription}
+  {triggerHref}
+  on:change={({ detail }) => {
+    console.log("change event", detail);
+  }}
+>
+  <Tab label="Tab 1" />
+  <Tab label="Tab 2" disabled />
+  <Tab label="Tab 3" />
+  <svelte:fragment slot="content">
+    <TabContent>Content 1</TabContent>
+    <TabContent>Content 2</TabContent>
+    <TabContent>Content 3</TabContent>
+  </svelte:fragment>
+</Tabs>

tests/Tabs/Tabs.test.ts

@@ -0,0 +1,129 @@
+import { render, screen } from "@testing-library/svelte";
+import { user } from "../setup-tests";
+import Tabs from "./Tabs.test.svelte";
+
+describe("Tabs", () => {
+  let consoleLog: ReturnType<typeof vi.spyOn>;
+
+  beforeEach(() => {
+    consoleLog = vi.spyOn(console, "log");
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it("should render with default props", () => {
+    render(Tabs);
+
+    expect(screen.getByRole("tab", { name: "Tab 1" })).toBeInTheDocument();
+    expect(screen.getByRole("tab", { name: "Tab 2" })).toBeInTheDocument();
+    expect(screen.getByRole("tab", { name: "Tab 3" })).toBeInTheDocument();
+    expect(screen.getByText("Content 1")).toBeVisible();
+    expect(screen.getByText("Content 2")).not.toBeVisible();
+    expect(screen.getByText("Content 3")).not.toBeVisible();
+  });
+
+  it("should select initial tab based on selected prop", () => {
+    render(Tabs, { props: { selected: 2 } });
+
+    const tab3 = screen.getByRole("tab", { name: "Tab 3" });
+    expect(tab3).toHaveAttribute("aria-selected", "true");
+    expect(screen.getByText("Content 3")).toBeVisible();
+    expect(screen.getByText("Content 1")).not.toBeVisible();
+    expect(screen.getByText("Content 2")).not.toBeVisible();
+  });
+
+  it("should change tab on click", async () => {
+    render(Tabs);
+
+    const tab3 = screen.getByRole("tab", { name: "Tab 3" });
+    await user.click(tab3);
+
+    expect(tab3.getAttribute("aria-selected")).toBe("true");
+    expect(screen.getByText("Content 3")).toBeVisible();
+    expect(consoleLog).toHaveBeenCalledWith("change event", 2);
+  });
+
+  it("should not select disabled tabs", async () => {
+    render(Tabs);
+
+    const tab2 = screen.getByRole("tab", { name: "Tab 2" });
+    expect(tab2).toHaveAttribute("aria-disabled", "true");
+    await user.click(tab2);
+
+    expect(tab2).toHaveAttribute("aria-selected", "false");
+    expect(screen.getByText("Content 1")).toBeVisible();
+  });
+
+  it("should support keyboard navigation", async () => {
+    render(Tabs);
+
+    const tab1 = screen.getByRole("tab", { name: "Tab 1" });
+    await user.click(tab1);
+
+    await user.keyboard("{ArrowRight}");
+    expect(screen.getByRole("tab", { name: "Tab 3" })).toHaveFocus();
+    expect(consoleLog).toHaveBeenCalledWith("change event", 2);
+
+    await user.keyboard("{ArrowLeft}");
+    expect(tab1).toHaveFocus();
+    expect(consoleLog).toHaveBeenCalledWith("change event", 0);
+  });
+
+  it("should render container type tabs", () => {
+    const { container } = render(Tabs, {
+      props: { type: "container" },
+    });
+
+    expect(container.querySelector(".bx--tabs--container")).not.toBeNull();
+  });
+
+  it("should support auto width", () => {
+    const { container } = render(Tabs, {
+      props: { autoWidth: true },
+    });
+
+    const tabs = container.querySelectorAll(".bx--tabs__nav-item");
+    tabs.forEach((tab) => {
+      expect(tab).not.toHaveStyle({ width: "10rem" });
+    });
+  });
+
+  it("should show dropdown on trigger click", async () => {
+    const { container } = render(Tabs);
+
+    const trigger = container.querySelector(".bx--tabs-trigger");
+    if (!trigger) throw new Error("Trigger element not found");
+
+    await user.click(trigger);
+    expect(container.querySelector(".bx--tabs__nav--hidden")).toBeNull();
+  });
+
+  it("should update trigger text when tab changes", async () => {
+    const { container } = render(Tabs);
+
+    const tab3 = screen.getByText("Tab 3");
+    await user.click(tab3);
+
+    const triggerText = container.querySelector(".bx--tabs-trigger-text");
+    expect(triggerText).toHaveTextContent("Tab 3");
+  });
+
+  it("should support custom trigger href", () => {
+    const { container } = render(Tabs, {
+      props: { triggerHref: "#custom" },
+    });
+
+    const triggerLink = container.querySelector(".bx--tabs-trigger-text");
+    expect(triggerLink).toHaveAttribute("href", "#custom");
+  });
+
+  it("should support custom icon description", () => {
+    render(Tabs, {
+      props: { iconDescription: "Custom description" },
+    });
+
+    expect(screen.getByTitle("Custom description")).toBeInTheDocument();
+  });
+});