Support rendering <Fragment> in MDX <Content /> component (#5522)

withastro · Dec 5, 2022 · efc4363 · efc4363
1 parent c1a944d
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Showing 12 changed files with 286 additions and 8 deletions.
diff --git a/.changeset/sweet-chairs-buy.md b/.changeset/sweet-chairs-buy.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/mdx': patch
+---
+
+Support use of `<Fragment>` in MDX files rendered with `<Content />` component
diff --git a/packages/astro/src/core/render/core.ts b/packages/astro/src/core/render/core.ts
@@ -113,6 +113,7 @@ export async function renderPage(mod: ComponentInstance, ctx: RenderContext, env
 	}
 
 	// HACK: expose `Fragment` for all MDX components
+	// TODO: Remove in Astro v2 — redundant as of @astrojs/mdx@>0.12.0
 	if (typeof mod.default === 'function' && mod.default.name.startsWith('MDX')) {
 		Object.assign(pageProps, {
 			components: Object.assign((pageProps?.components as any) ?? {}, { Fragment }),

diff --git a/packages/integrations/mdx/src/index.ts b/packages/integrations/mdx/src/index.ts
@@ -132,11 +132,18 @@ export default function mdx(mdxOptions: MdxOptions = {}): AstroIntegration {
 								transform(code, id) {
 									if (!id.endsWith('.mdx')) return;
 
-									// Ensures styles and scripts are injected into a `<head>`
-									// When a layout is not applied
-									code += `\nMDXContent[Symbol.for('astro.needsHeadRendering')] = !Boolean(frontmatter.layout);`;
-
-									const [, moduleExports] = parseESM(code);
+									const [moduleImports, moduleExports] = parseESM(code);
+
+									// Fragment import should already be injected, but check just to be safe.
+									const importsFromJSXRuntime = moduleImports
+										.filter(({ n }) => n === 'astro/jsx-runtime')
+										.map(({ ss, se }) => code.substring(ss, se));
+									const hasFragmentImport = importsFromJSXRuntime.some((statement) =>
+										/[\s,{](Fragment,|Fragment\s*})/.test(statement)
+									);
+									if (!hasFragmentImport) {
+										code = 'import { Fragment } from "astro/jsx-runtime"\n' + code;
+									}
 
 									const { fileUrl, fileId } = getFileInfo(id, config);
 									if (!moduleExports.includes('url')) {
@@ -156,9 +163,19 @@ export default function mdx(mdxOptions: MdxOptions = {}): AstroIntegration {
 										)}) };`;
 									}
 									if (!moduleExports.includes('Content')) {
-										code += `\nexport const Content = MDXContent;`;
+										// Make `Content` the default export so we can wrap `MDXContent` and pass in `Fragment`
+										code = code.replace('export default MDXContent;', '');
+										code += `\nexport const Content = (props = {}) => MDXContent({
+											...props,
+											components: { Fragment, ...props.components },
+										});
+										export default Content;`;
 									}
 
+									// Ensures styles and scripts are injected into a `<head>`
+									// When a layout is not applied
+									code += `\nContent[Symbol.for('astro.needsHeadRendering')] = !Boolean(frontmatter.layout);`;
+
 									if (command === 'dev') {
 										// TODO: decline HMR updates until we have a stable approach
 										code += `\nif (import.meta.hot) {

diff --git a/...es/integrations/mdx/test/fixtures/mdx-component/src/components/WithFragment.mdx b/...es/integrations/mdx/test/fixtures/mdx-component/src/components/WithFragment.mdx
@@ -0,0 +1,3 @@
+# MDX containing `<Fragment />`
+
+<p><Fragment>bar</Fragment></p>
diff --git a/packages/integrations/mdx/test/fixtures/mdx-component/src/pages/glob.astro b/packages/integrations/mdx/test/fixtures/mdx-component/src/pages/glob.astro
@@ -1,11 +1,20 @@
 ---
+import { parse } from 'node:path';
 const components = await Astro.glob('../components/*.mdx');
 ---
 
 <div data-default-export>
-	{components.map(Component => <Component.default />)}
+	{components.map(Component => (
+		<div data-file={parse(Component.file).base}>
+			<Component.default />
+		</div>
+	))}
 </div>
 
 <div data-content-export>
-	{components.map(({ Content }) => <Content />)}
+	{components.map(({ Content, file }) => (
+		<div data-file={parse(file).base}>
+			<Content />
+		</div>
+	))}
 </div>
diff --git a/packages/integrations/mdx/test/fixtures/mdx-component/src/pages/w-fragment.astro b/packages/integrations/mdx/test/fixtures/mdx-component/src/pages/w-fragment.astro
@@ -0,0 +1,5 @@
+---
+import WithFragment from '../components/WithFragment.mdx';
+---
+
+<WithFragment />
diff --git a/packages/integrations/mdx/test/fixtures/mdx-slots/src/components/Slotted.astro b/packages/integrations/mdx/test/fixtures/mdx-slots/src/components/Slotted.astro
@@ -0,0 +1,4 @@
+<div class="slotted">
+	<div data-default-slot><slot /></div>
+	<div data-named-slot><slot name="named" /></div>
+</div>
diff --git a/packages/integrations/mdx/test/fixtures/mdx-slots/src/components/Test.mdx b/packages/integrations/mdx/test/fixtures/mdx-slots/src/components/Test.mdx
@@ -0,0 +1,15 @@
+import Slotted from './Slotted.astro'
+
+# Hello slotted component!
+
+<Slotted>
+
+Default content.
+
+<Fragment slot="named">
+
+Content for named slot.
+
+</Fragment>
+
+</Slotted>
diff --git a/packages/integrations/mdx/test/fixtures/mdx-slots/src/pages/glob.astro b/packages/integrations/mdx/test/fixtures/mdx-slots/src/pages/glob.astro
@@ -0,0 +1,11 @@
+---
+const components = await Astro.glob('../components/*.mdx');
+---
+
+<div data-default-export>
+	{components.map(Component => <Component.default />)}
+</div>
+
+<div data-content-export>
+	{components.map(({ Content }) => <Content />)}
+</div>
diff --git a/packages/integrations/mdx/test/fixtures/mdx-slots/src/pages/index.astro b/packages/integrations/mdx/test/fixtures/mdx-slots/src/pages/index.astro
@@ -0,0 +1,5 @@
+---
+import Test from '../components/Test.mdx';
+---
+
+<Test />
diff --git a/packages/integrations/mdx/test/mdx-component.test.js b/packages/integrations/mdx/test/mdx-component.test.js
@@ -51,6 +51,41 @@ describe('MDX Component', () => {
 			expect(h1.textContent).to.equal('Hello component!');
 			expect(foo.textContent).to.equal('bar');
 		});
+
+		describe('with <Fragment>', () => {
+			it('supports top-level imports', async () => {
+				const html = await fixture.readFile('/w-fragment/index.html');
+				const { document } = parseHTML(html);
+
+				const h1 = document.querySelector('h1');
+				const p = document.querySelector('p');
+
+				expect(h1.textContent).to.equal('MDX containing <Fragment />');
+				expect(p.textContent).to.equal('bar');
+			});
+
+			it('supports glob imports - <Component.default />', async () => {
+				const html = await fixture.readFile('/glob/index.html');
+				const { document } = parseHTML(html);
+
+				const h = document.querySelector('[data-default-export] [data-file="WithFragment.mdx"] h1');
+				const p = document.querySelector('[data-default-export] [data-file="WithFragment.mdx"] p');
+
+				expect(h.textContent).to.equal('MDX containing <Fragment />');
+				expect(p.textContent).to.equal('bar');
+			});
+
+			it('supports glob imports - <Content />', async () => {
+				const html = await fixture.readFile('/glob/index.html');
+				const { document } = parseHTML(html);
+
+				const h = document.querySelector('[data-content-export] [data-file="WithFragment.mdx"] h1');
+				const p = document.querySelector('[data-content-export] [data-file="WithFragment.mdx"] p');
+
+				expect(h.textContent).to.equal('MDX containing <Fragment />');
+				expect(p.textContent).to.equal('bar');
+			});
+		});
 	});
 
 	describe('dev', () => {
@@ -108,5 +143,49 @@ describe('MDX Component', () => {
 			expect(h1.textContent).to.equal('Hello component!');
 			expect(foo.textContent).to.equal('bar');
 		});
+
+		describe('with <Fragment>', () => {
+			it('supports top-level imports', async () => {
+				const res = await fixture.fetch('/w-fragment');
+				expect(res.status).to.equal(200);
+
+				const html = await res.text();
+				const { document } = parseHTML(html);
+
+				const h1 = document.querySelector('h1');
+				const p = document.querySelector('p');
+
+				expect(h1.textContent).to.equal('MDX containing <Fragment />');
+				expect(p.textContent).to.equal('bar');
+			});
+
+			it('supports glob imports - <Component.default />', async () => {
+				const res = await fixture.fetch('/glob');
+				expect(res.status).to.equal(200);
+
+				const html = await res.text();
+				const { document } = parseHTML(html);
+
+				const h = document.querySelector('[data-default-export] [data-file="WithFragment.mdx"] h1');
+				const p = document.querySelector('[data-default-export] [data-file="WithFragment.mdx"] p');
+
+				expect(h.textContent).to.equal('MDX containing <Fragment />');
+				expect(p.textContent).to.equal('bar');
+			});
+
+			it('supports glob imports - <Content />', async () => {
+				const res = await fixture.fetch('/glob');
+				expect(res.status).to.equal(200);
+
+				const html = await res.text();
+				const { document } = parseHTML(html);
+
+				const h = document.querySelector('[data-content-export] [data-file="WithFragment.mdx"] h1');
+				const p = document.querySelector('[data-content-export] [data-file="WithFragment.mdx"] p');
+
+				expect(h.textContent).to.equal('MDX containing <Fragment />');
+				expect(p.textContent).to.equal('bar');
+			});
+		});
 	});
 });
diff --git a/packages/integrations/mdx/test/mdx-slots.js b/packages/integrations/mdx/test/mdx-slots.js
@@ -0,0 +1,124 @@
+import mdx from '@astrojs/mdx';
+
+import { expect } from 'chai';
+import { parseHTML } from 'linkedom';
+import { loadFixture } from '../../../astro/test/test-utils.js';
+
+describe('MDX slots', () => {
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: new URL('./fixtures/mdx-slots/', import.meta.url),
+			integrations: [mdx()],
+		});
+	});
+
+	describe('build', () => {
+		before(async () => {
+			await fixture.build();
+		});
+
+		it('supports top-level imports', async () => {
+			const html = await fixture.readFile('/index.html');
+			const { document } = parseHTML(html);
+
+			const h1 = document.querySelector('h1');
+			const defaultSlot = document.querySelector('[data-default-slot]');
+			const namedSlot = document.querySelector('[data-named-slot]');
+
+			expect(h1.textContent).to.equal('Hello slotted component!');
+			expect(defaultSlot.textContent).to.equal('Default content.');
+			expect(namedSlot.textContent).to.equal('Content for named slot.');
+		});
+
+		it('supports glob imports - <Component.default />', async () => {
+			const html = await fixture.readFile('/glob/index.html');
+			const { document } = parseHTML(html);
+
+			const h1 = document.querySelector('[data-default-export] h1');
+			const defaultSlot = document.querySelector('[data-default-export] [data-default-slot]');
+			const namedSlot = document.querySelector('[data-default-export] [data-named-slot]');
+
+			expect(h1.textContent).to.equal('Hello slotted component!');
+			expect(defaultSlot.textContent).to.equal('Default content.');
+			expect(namedSlot.textContent).to.equal('Content for named slot.');
+		});
+
+		it('supports glob imports - <Content />', async () => {
+			const html = await fixture.readFile('/glob/index.html');
+			const { document } = parseHTML(html);
+
+			const h1 = document.querySelector('[data-content-export] h1');
+			const defaultSlot = document.querySelector('[data-content-export] [data-default-slot]');
+			const namedSlot = document.querySelector('[data-content-export] [data-named-slot]');
+
+			expect(h1.textContent).to.equal('Hello slotted component!');
+			expect(defaultSlot.textContent).to.equal('Default content.');
+			expect(namedSlot.textContent).to.equal('Content for named slot.');
+		});
+	});
+
+	describe('dev', () => {
+		let devServer;
+
+		before(async () => {
+			devServer = await fixture.startDevServer();
+		});
+
+		after(async () => {
+			await devServer.stop();
+		});
+
+		it('supports top-level imports', async () => {
+			const res = await fixture.fetch('/');
+
+			expect(res.status).to.equal(200);
+
+			const html = await res.text();
+			const { document } = parseHTML(html);
+
+			const h1 = document.querySelector('h1');
+			const defaultSlot = document.querySelector('[data-default-slot]');
+			const namedSlot = document.querySelector('[data-named-slot]');
+
+			expect(h1.textContent).to.equal('Hello slotted component!');
+			expect(defaultSlot.textContent).to.equal('Default content.');
+			expect(namedSlot.textContent).to.equal('Content for named slot.');
+		});
+
+		it('supports glob imports - <Component.default />', async () => {
+			const res = await fixture.fetch('/glob');
+
+			expect(res.status).to.equal(200);
+
+			const html = await res.text();
+			const { document } = parseHTML(html);
+
+			const h1 = document.querySelector('[data-default-export] h1');
+			const defaultSlot = document.querySelector('[data-default-export] [data-default-slot]');
+			const namedSlot = document.querySelector('[data-default-export] [data-named-slot]');
+
+			expect(h1.textContent).to.equal('Hello slotted component!');
+			expect(defaultSlot.textContent).to.equal('Default content.');
+			expect(namedSlot.textContent).to.equal('Content for named slot.');
+		});
+
+		it('supports glob imports - <Content />', async () => {
+			const res = await fixture.fetch('/glob');
+
+			expect(res.status).to.equal(200);
+
+			const html = await res.text();
+			const { document } = parseHTML(html);
+
+			const h1 = document.querySelector('[data-content-export] h1');
+			const defaultSlot = document.querySelector('[data-content-export] [data-default-slot]');
+			const namedSlot = document.querySelector('[data-content-export] [data-named-slot]');
+
+			expect(h1.textContent).to.equal('Hello slotted component!');
+			expect(defaultSlot.textContent).to.equal('Default content.');
+			expect(namedSlot.textContent).to.equal('Content for named slot.');
+		});
+	});
+});