Fix: menu_order validation to allow zero and negative values

packages/fields/src/actions/reorder-page.tsx

@@ -35,8 +35,7 @@ interface Action< Item > {
 function isItemValid( item: BasePost ): boolean {
 	return (
 		typeof item.menu_order === 'number' &&
-		Number.isInteger( item.menu_order ) &&
-		item.menu_order > 0
+		Number.isInteger( item.menu_order )
 	);
 }
 

test/e2e/specs/site-editor/pages.spec.js

@@ -321,4 +321,76 @@ test.describe( 'Pages', () => {
 				.getByText( 'Change template' )
 		).toBeDisabled();
 	} );
+
+	// Regression test for https://github.com/WordPress/gutenberg/issues/73820
+	test( 'should allow setting page order to zero and negative values', async ( {
+		admin,
+		page,
+		requestUtils,
+	} ) => {
+		// Create a published page for testing
+		await requestUtils.createPage( {
+			title: 'Order Test Page',
+			status: 'publish',
+		} );
+
+		await admin.visitSiteEditor();
+		await page.getByRole( 'button', { name: 'Pages' } ).click();
+
+		// Switch to table layout to access actions
+		await page.getByRole( 'button', { name: 'Layout' } ).click();
+		await page.getByRole( 'menuitemradio', { name: 'Table' } ).click();
+
+		// Open actions menu for the test page
+		let row = page.getByRole( 'row', { name: /Order Test Page/ } );
+		await row.getByRole( 'button', { name: 'Actions' } ).click();
+
+		// Click on Order action
+		await page.getByRole( 'menuitem', { name: 'Order' } ).click();
+
+		// Get the order input and save button
+		let orderInput = page.getByRole( 'spinbutton', { name: 'Order' } );
+		const saveButton = page.getByRole( 'button', { name: 'Save' } );
+
+		// Test that 0 is valid
+		await orderInput.fill( '0' );
+		await expect( saveButton ).toBeEnabled();
+
+		// Test that negative values are valid
+		await orderInput.fill( '-1' );
+		await expect( saveButton ).toBeEnabled();
+
+		await orderInput.fill( '-100' );
+		await expect( saveButton ).toBeEnabled();
+
+		// Test that positive values are still valid
+		await orderInput.fill( '5' );
+		await expect( saveButton ).toBeEnabled();
+
+		// Save with a negative value to verify it persists
+		await orderInput.fill( '-5' );
+		await saveButton.click();
+
+		// Verify success notice
+		await expect(
+			page.locator(
+				'role=button[name="Dismiss this notice"i] >> text="Order updated."'
+			)
+		).toBeVisible();
+
+		// Reload the page to verify the value persisted
+		await admin.visitSiteEditor();
+		await page.getByRole( 'button', { name: 'Pages' } ).click();
+		await page.getByRole( 'button', { name: 'Layout' } ).click();
+		await page.getByRole( 'menuitemradio', { name: 'Table' } ).click();
+
+		// Open Order action again for the same page
+		row = page.getByRole( 'row', { name: /Order Test Page/ } );
+		await row.getByRole( 'button', { name: 'Actions' } ).click();
+		await page.getByRole( 'menuitem', { name: 'Order' } ).click();
+
+		// Verify the negative value was persisted
+		orderInput = page.getByRole( 'spinbutton', { name: 'Order' } );
+		await expect( orderInput ).toHaveValue( '-5' );
+	} );
 } );