diff --git a/src/libs/__test__/formatter.spec.ts b/src/libs/__test__/formatter.spec.ts
new file mode 100644
index 0000000..0932aa5
--- /dev/null
+++ b/src/libs/__test__/formatter.spec.ts
@@ -0,0 +1,7 @@
+import { test, expect } from "vitest"
+import { convertUnixTimeStampToReadableTime } from "../formatter"
+
+test("test", () => {
+  const time = convertUnixTimeStampToReadableTime(1709112255)
+  expect(time).toBe("2024-02-28 17:24")
+})
diff --git a/src/libs/__test__/math.spec.ts b/src/libs/__test__/math.spec.ts
new file mode 100644
index 0000000..492dcd7
--- /dev/null
+++ b/src/libs/__test__/math.spec.ts
@@ -0,0 +1,11 @@
+import { generateRandomInteger } from "../math"
+
+for (let i = 0; i < 5; i++) {
+  test("generate random integer", () => {
+    expect(generateRandomInteger(5, 1)).toBeLessThanOrEqual(5)
+    expect(generateRandomInteger(5, 1)).toBeGreaterThanOrEqual(1)
+
+    expect(generateRandomInteger(7, 2)).toBeLessThanOrEqual(7)
+    expect(generateRandomInteger(5, 2)).toBeGreaterThanOrEqual(2)
+  })
+}
diff --git a/src/stores/__test__/settings.spec.ts b/src/stores/__test__/settings.spec.ts
new file mode 100644
index 0000000..4a8ea6a
--- /dev/null
+++ b/src/stores/__test__/settings.spec.ts
@@ -0,0 +1,17 @@
+import { useSettingsStore } from "../settings"
+
+describe("Settings Store", () => {
+  beforeEach(() => {
+    // creates a fresh pinia and makes it active
+    // so it's automatically picked up by any useStore() call
+    // without having to pass it to it: `useStore(pinia)`
+    setActivePinia(createPinia())
+  })
+
+  it("reset setting", () => {
+    const store = useSettingsStore()
+    store.settings.displayingItemId.value = false
+    store.settingOperations.reset()
+    expect(store.settings.displayingItemId.value).toBeTruthy()
+  })
+})