1 files changed, 60 insertions, 0 deletions
diff --git a/packages/integrations/mdx/test/mdx-frontmatter-injection.test.js b/packages/integrations/mdx/test/mdx-frontmatter-injection.test.js
new file mode 100644
index 000000000..5c8b69d07
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+++ b/packages/integrations/mdx/test/mdx-frontmatter-injection.test.js
@@ -0,0 +1,60 @@
+import * as assert from 'node:assert/strict';
+import { before, describe, it } from 'node:test';
+import { parseHTML } from 'linkedom';
+import { loadFixture } from '../../../astro/test/test-utils.js';
+
+const FIXTURE_ROOT = new URL('./fixtures/mdx-frontmatter-injection/', import.meta.url);
+
+describe('MDX frontmatter injection', () => {
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: FIXTURE_ROOT,
+		});
+		await fixture.build();
+	});
+
+	it('remark supports custom vfile data - get title', async () => {
+		const frontmatterByPage = JSON.parse(await fixture.readFile('/glob.json'));
+		const titles = frontmatterByPage.map((frontmatter = {}) => frontmatter.title);
+		assert.equal(titles.includes('Page 1'), true);
+		assert.equal(titles.includes('Page 2'), true);
+	});
+
+	it('rehype supports custom vfile data - reading time', async () => {
+		const frontmatterByPage = JSON.parse(await fixture.readFile('/glob.json'));
+		const readingTimes = frontmatterByPage.map(
+			(frontmatter = {}) => frontmatter.injectedReadingTime,
+		);
+		assert.equal(readingTimes.length > 0, true);
+		for (let readingTime of readingTimes) {
+			assert.notEqual(readingTime, null);
+			assert.match(readingTime.text, /^\d+ min read/);
+		}
+	});
+
+	it('allow user frontmatter mutation', async () => {
+		const frontmatterByPage = JSON.parse(await fixture.readFile('/glob.json'));
+		const descriptions = frontmatterByPage.map((frontmatter = {}) => frontmatter.description);
+		assert.equal(
+			descriptions.includes('Processed by remarkDescription plugin: Page 1 description'),
+			true,
+		);
+		assert.equal(
+			descriptions.includes('Processed by remarkDescription plugin: Page 2 description'),
+			true,
+		);
+	});
+
+	it('passes injected frontmatter to layouts', async () => {
+		const html1 = await fixture.readFile('/page-1/index.html');
+		const html2 = await fixture.readFile('/page-2/index.html');
+
+		const title1 = parseHTML(html1).document.querySelector('title');
+		const title2 = parseHTML(html2).document.querySelector('title');
+
+		assert.equal(title1.innerHTML, 'Page 1');
+		assert.equal(title2.innerHTML, 'Page 2');
+	});
+});