add unit tests

tests/components/DatePicker.test.tsx

@@ -0,0 +1,62 @@
+import { fireEvent, render, screen } from '@testing-library/react';
+import { describe, expect, it, vi } from 'vitest';
+import { DatePicker } from '../../src/components/DatePicker';
+
+describe('DatePicker', () => {
+    it('supports datetime-local type and change callback', () => {
+        const onChange = vi.fn();
+        render(<DatePicker label="Schedule" type="datetime-local" value="" onChange={onChange} />);
+
+        const input = screen.getByLabelText('Schedule') as HTMLInputElement;
+        expect(input.type).toBe('datetime-local');
+
+        fireEvent.change(input, { target: { value: '2031-05-20T14:30' } });
+        expect(onChange).toHaveBeenCalledTimes(1);
+    });
+
+    it('supports date type and disabled state', () => {
+        render(
+            <DatePicker
+                label="Publish date"
+                type="date"
+                value="2031-05-20"
+                onChange={() => {}}
+                disabled
+            />,
+        );
+
+        const input = screen.getByLabelText('Publish date') as HTMLInputElement;
+        expect(input.type).toBe('date');
+        expect(input).toBeDisabled();
+    });
+
+    it('renders right icon and error message', () => {
+        const { container } = render(
+            <DatePicker
+                label="Schedule"
+                type="datetime-local"
+                value=""
+                onChange={() => {}}
+                rightIcon={<span data-testid="right-icon">R</span>}
+                error="Invalid date"
+                inputClassName="custom-input"
+            />,
+        );
+
+        const input = container.querySelector('input');
+        expect(input).toBeInstanceOf(HTMLInputElement);
+        expect(screen.getByTestId('right-icon')).toBeInTheDocument();
+        expect(input).toHaveClass('pr-10');
+        expect(input).toHaveClass('custom-input');
+        expect(screen.getByText('Invalid date')).toBeInTheDocument();
+    });
+
+    it('supports inline layout', () => {
+        const { container } = render(
+            <DatePicker label="Start time" type="time" value="09:00" onChange={() => {}} layout="inline" />,
+        );
+
+        expect(container.querySelector('label')).toHaveClass('inline-flex');
+        expect(container.querySelector('label > div')).not.toHaveClass('mt-1');
+    });
+});