Add testing to the "don’t generate invalid <link rel="canonical"/> with missing href" solution

packages/starlight/__tests__/basics/omit-canonical.test.ts

@@ -0,0 +1,32 @@
+import { expect, test, vi } from 'vitest';
+import { getRouteDataTestContext } from '../test-utils';
+import { generateRouteData } from '../../utils/routing/data';
+import { routes } from '../../utils/routing';
+
+vi.mock('astro:content', async () =>
+	(await import('../test-utils')).mockedAstroContent({
+		docs: [
+			['index.mdx', { title: 'Home Page' }],
+			[
+				'environmental-impact.md',
+				{
+					title: 'Eco-friendly docs',
+					description:
+						'Learn how Starlight can help you build greener documentation sites and reduce your carbon footprint.',
+				},
+			],
+		],
+	})
+);
+
+test('omits link canonical tag when site is not set', () => {
+	const route = routes[0]!;
+	const { head } = generateRouteData({
+		props: { ...route, headings: [] },
+		context: getRouteDataTestContext(undefined, false),
+	});
+
+	const canonicalExists = head.some((tag) => tag.tag === 'link' && tag.attrs?.rel === 'canonical');
+
+	expect(canonicalExists).toBe(false);
+});

packages/starlight/__tests__/head/head.test.ts

@@ -188,7 +188,15 @@ test('places the default favicon below any user provided icons', () => {
 	expect(defaultFaviconIndex).toBeGreaterThan(userFaviconIndex);
 });
 
-function getTestHead(heads: HeadConfig = [], route = routes[0]!): HeadConfig {
+test('omits meta og:url tag when site is not set', () => {
+	const head = getTestHead(undefined, undefined, false);
+
+	const ogUrlExists = head.some((tag) => tag.tag === 'meta' && tag.attrs?.property === 'og:url');
+
+	expect(ogUrlExists).toBe(false);
+});
+
+function getTestHead(heads: HeadConfig = [], route = routes[0]!, setSite?: boolean): HeadConfig {
 	return generateRouteData({
 		props: {
 			...route,
@@ -201,6 +209,9 @@ function getTestHead(heads: HeadConfig = [], route = routes[0]!): HeadConfig {
 				},
 			},
 		},
-		context: getRouteDataTestContext(),
+		context:
+			setSite === undefined
+				? getRouteDataTestContext()
+				: getRouteDataTestContext(undefined, setSite),
 	}).head;
 }

packages/starlight/__tests__/test-utils.ts

@@ -102,11 +102,15 @@ export async function mockedCollectionConfig(docsUserSchema?: Parameters<typeof
 	};
 }
 
-export function getRouteDataTestContext(pathname?: string): RouteDataContext {
+export function getRouteDataTestContext(
+	pathname?: string,
+	setSite: boolean = true
+): RouteDataContext {
 	const site = new URL('https://example.com');
+
 	return {
 		generator: 'Astro',
-		site,
 		url: pathname ? new URL(pathname, site) : site,
+		site: setSite ? site : undefined,
 	};
 }