testing 101

Signed-off-by: Kenneth Obsequio <k80308392@gmail.com>

tests/utils/datetime.test.js

@@ -0,0 +1,74 @@
+'use strict';
+
+const { fmtDate, fmtDateTime, fmtTime } = require('../../utils/datetime.util');
+
+const ISO = '2026-06-20T14:30:00.000Z'; // Saturday, June 20, 2026, 2:30 PM UTC
+
+// ── fmtDate ───────────────────────────────────────────────────────────────────
+
+describe('fmtDate()', () => {
+  test('null → returns —', () => {
+    expect(fmtDate(null)).toBe('—');
+  });
+
+  test('empty string → returns —', () => {
+    expect(fmtDate('')).toBe('—');
+  });
+
+  test('formats year correctly', () => {
+    expect(fmtDate(ISO)).toContain('2026');
+  });
+
+  test('formats month correctly (June)', () => {
+    expect(fmtDate(ISO)).toContain('June');
+  });
+
+  test('formats day correctly (20)', () => {
+    expect(fmtDate(ISO)).toContain('20');
+  });
+
+  test('accepts Date object as well as ISO string', () => {
+    const d = new Date(ISO);
+    expect(fmtDate(d)).toContain('2026');
+  });
+});
+
+// ── fmtDateTime ───────────────────────────────────────────────────────────────
+
+describe('fmtDateTime()', () => {
+  test('null → returns —', () => {
+    expect(fmtDateTime(null)).toBe('—');
+  });
+
+  test('contains date portion', () => {
+    expect(fmtDateTime(ISO)).toContain('2026');
+    expect(fmtDateTime(ISO)).toContain('June');
+  });
+
+  test('contains time portion (2:30 PM UTC)', () => {
+    const out = fmtDateTime(ISO);
+    expect(out).toMatch(/2:30/);
+    expect(out).toContain('UTC');
+  });
+});
+
+// ── fmtTime ───────────────────────────────────────────────────────────────────
+
+describe('fmtTime()', () => {
+  test('null → returns —', () => {
+    expect(fmtTime(null)).toBe('—');
+  });
+
+  test('outputs time with AM/PM', () => {
+    expect(fmtTime(ISO)).toMatch(/\d+:\d{2}\s*(AM|PM)/);
+  });
+
+  test('contains timezone label (UTC)', () => {
+    expect(fmtTime(ISO)).toContain('UTC');
+  });
+
+  test('locale option changes output', () => {
+    const en = fmtTime(ISO, { locale: 'en-US' });
+    expect(en).toBeTruthy();
+  });
+});