#155

frontend/src/lib/utils.test.ts

@@ -0,0 +1,28 @@
+import { describe, expect, it } from 'vitest'
+
+import { cn, originalCreatedAtString, toDate } from '@/lib/utils'
+
+describe ('utils', () => {
+  it ('converts strings to dates and leaves date instances intact', () => {
+    const date = new Date ('2026-01-02T03:04:05Z')
+
+    expect (toDate ('2026-01-02T03:04:05Z')).toBeInstanceOf (Date)
+    expect (toDate (date)).toBe (date)
+  })
+
+  it ('merges conditional Tailwind classes', () => {
+    const hidden = false
+
+    expect (cn ('p-2', hidden && 'hidden', 'p-4')).toBe ('p-4')
+  })
+
+  it ('renders unknown original creation time ranges', () => {
+    expect (originalCreatedAtString (null, null)).toBe ('年月日不詳')
+    expect (
+        originalCreatedAtString (
+            '2026-01-01T00:00:00+09:00',
+            '2026-01-02T00:00:00+09:00',
+        ),
+    ).toContain ('時刻不詳')
+  })
+})