feat: Admin Area General Settings and Categories 1.05

tests/frontend/admin-general-pure.spec.ts

@@ -1,6 +1,8 @@
 import {
+  datetimeMessage,
   deriveEventState,
   endAfterStartValidator,
+  isoDatetimeValidator,
   normalizePageTitle,
   pageTitleError,
   pageTitleMessage,
@@ -161,3 +163,43 @@ describe('pageTitleMessage', () => {
     expect(pageTitleMessage('a'.repeat(121), { maxlength: { requiredLength: 120 } })).toBe(maxLengthMsg);
   });
 });
+
+describe('isoDatetimeValidator', () => {
+  it('returns null for an empty value (unconfigured is allowed)', () => {
+    expect(isoDatetimeValidator({ value: '' })).toBeNull();
+    expect(isoDatetimeValidator({ value: null })).toBeNull();
+    expect(isoDatetimeValidator({ value: undefined })).toBeNull();
+  });
+
+  it('returns null for a valid ISO-8601 datetime', () => {
+    expect(isoDatetimeValidator({ value: '2026-08-15T10:30:00.000Z' })).toBeNull();
+  });
+
+  it('returns { invalidDatetime: true } for a non-datetime string', () => {
+    expect(isoDatetimeValidator({ value: 'not-a-date' })).toEqual({ invalidDatetime: true });
+    expect(isoDatetimeValidator({ value: 'also-not-a-date' })).toEqual({ invalidDatetime: true });
+  });
+});
+
+describe('datetimeMessage', () => {
+  it('returns the per-field error when controlErrors carries invalidDatetime', () => {
+    expect(datetimeMessage('Event start', 'not-a-date', { invalidDatetime: true }))
+      .toBe('Event start must be a valid ISO-8601 datetime.');
+    expect(datetimeMessage('Event end', 'garbage', { invalidDatetime: true }))
+      .toBe('Event end must be a valid ISO-8601 datetime.');
+  });
+
+  it('falls back to detecting an unparseable value when controlErrors are absent', () => {
+    expect(datetimeMessage('Event start', 'not-a-date', null))
+      .toBe('Event start must be a valid ISO-8601 datetime.');
+  });
+
+  it('returns null for an empty value', () => {
+    expect(datetimeMessage('Event start', '', null)).toBeNull();
+    expect(datetimeMessage('Event start', '', { invalidDatetime: false as any })).toBeNull();
+  });
+
+  it('returns null for a valid ISO-8601 datetime', () => {
+    expect(datetimeMessage('Event start', '2026-08-15T10:30:00.000Z', null)).toBeNull();
+  });
+});