test: add some tests

tests/app/page.spec.ts

@@ -0,0 +1,6 @@
+import { expect, test } from "@playwright/test";
+
+test("VRT", async ({ page }) => {
+  await page.goto("/");
+  await expect(page).toHaveScreenshot();
+});

tests/components/sidebar/tool-groups.spec.ts

@@ -0,0 +1,35 @@
+import { expect, Page, test } from "@playwright/test";
+
+function navExpandedButton(page: Page) {
+  const nav = page.getByRole("navigation");
+  return nav.getByRole("button", { expanded: true });
+}
+
+test.describe("initial open/close states of accordion", () => {
+  test("closed when go to /", async ({ page }) => {
+    const button = navExpandedButton(page);
+
+    await page.goto("/");
+    await expect(button).not.toBeVisible();
+  });
+
+  test("closed when go to group pages", async ({ page }) => {
+    const button = navExpandedButton(page);
+
+    await page.goto("/converters");
+    await expect(button).not.toBeVisible();
+
+    await page.goto("/formatters");
+    await expect(button).not.toBeVisible();
+  });
+
+  test("opened when go to tool pages", async ({ page }) => {
+    const button = navExpandedButton(page);
+
+    await page.goto("/converters/number-base");
+    await expect(button).toBeVisible();
+
+    await page.goto("/formatters/json");
+    await expect(button).toBeVisible();
+  });
+});