Fix markdown page HMR (#8418)

Co-authored-by: Nate Moore <natemoo-re@users.noreply.github.com>

3 files changed, 12 insertions, 3 deletions

diff --git a/.changeset/twelve-cars-tell.md b/.changeset/twelve-cars-tell.md
new file mode 100644
index 000000000..a1812d637
--- /dev/null
+++ b/.changeset/twelve-cars-tell.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fix markdown page HMR
diff --git a/packages/astro/src/vite-plugin-markdown/index.ts b/packages/astro/src/vite-plugin-markdown/index.ts
index cc86d1fc1..deaccebef 100644
--- a/packages/astro/src/vite-plugin-markdown/index.ts
+++ b/packages/astro/src/vite-plugin-markdown/index.ts
@@ -107,7 +107,7 @@ export default function markdown({ settings, logger }: AstroPluginOptions): Plug
 				}
 
 				const code = escapeViteEnvReferences(`
-				import { unescapeHTML, spreadAttributes, createComponent, render, renderComponent } from ${JSON.stringify(
+				import { unescapeHTML, spreadAttributes, createComponent, render, renderComponent, maybeRenderHead } from ${JSON.stringify(
 					astroServerRuntimeModulePath
 				)};
 				import { AstroError, AstroErrorData } from ${JSON.stringify(astroErrorModulePath)};
@@ -180,10 +180,9 @@ export default function markdown({ settings, logger }: AstroPluginOptions): Plug
 							}, {
 								'default': () => render\`\${unescapeHTML(html)}\`
 							})}\`;`
-							: `render\`\${unescapeHTML(html)}\`;`
+							: `render\`\${maybeRenderHead(result)}\${unescapeHTML(html)}\`;`
 					}
 				});
-				Content[Symbol.for('astro.needsHeadRendering')] = ${layout ? 'false' : 'true'};
 				export default Content;
 				`);
 
diff --git a/packages/astro/test/astro-pages.test.js b/packages/astro/test/astro-pages.test.js
index 70f391be7..3d17b521d 100644
--- a/packages/astro/test/astro-pages.test.js
+++ b/packages/astro/test/astro-pages.test.js
@@ -49,5 +49,10 @@ describe('Pages', () => {
 
 			expect($('#testing').length).to.be.greaterThan(0);
 		});
+
+		it('should have Vite client in dev', async () => {
+			const html = await fixture.fetch('/').then((res) => res.text());
+			expect(html).to.include('/@vite/client', 'Markdown page does not have Vite client for HMR');
+		});
 	});
 });