From 7acf762c120a38a3cef4af597c116f0c37147311 Mon Sep 17 00:00:00 2001
From: Yoshiaki Togami <62130798+togami2864@users.noreply.github.com>
Date: Wed, 10 Nov 2021 02:46:01 +0900
Subject: [PATCH] Fix/check content type (#1754)

* test: add test case

* fix: add type guard insted of content.trim().length > 0

* test: fix test
---
 packages/astro/components/Markdown.astro                    | 2 +-
 packages/astro/test/astro-markdown.test.js                  | 6 ++++++
 .../fixtures/astro-markdown/src/pages/no-elements.astro     | 5 +++++
 3 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 packages/astro/test/fixtures/astro-markdown/src/pages/no-elements.astro

diff --git a/packages/astro/components/Markdown.astro b/packages/astro/components/Markdown.astro
index 862b3a2d4aa8..350b9c317986 100644
--- a/packages/astro/components/Markdown.astro
+++ b/packages/astro/components/Markdown.astro
@@ -20,7 +20,7 @@ const { privateRenderMarkdownDoNotUse: renderMarkdown } = (Astro as any);
 if (!content) {
   const { privateRenderSlotDoNotUse: renderSlot } = (Astro as any);
   content = await renderSlot('default');
-  if (content.trim().length > 0) {
+  if (content !== undefined && content !== null) {
     content = dedent(content);
   }
 }
diff --git a/packages/astro/test/astro-markdown.test.js b/packages/astro/test/astro-markdown.test.js
index de3a1f9962de..0d6aae978e56 100644
--- a/packages/astro/test/astro-markdown.test.js
+++ b/packages/astro/test/astro-markdown.test.js
@@ -140,4 +140,10 @@ describe('Astro Markdown', () => {
     // test Markdown rendered correctly via content prop
     expect($('h1').text()).to.equal('Foo');
   });
+
+  it("doesn't occurs TypeError when no elements", async () => {
+    const html = await fixture.readFile('/no-elements/index.html');
+    // render html without error
+    expect(html).to.be.ok;
+  });
 });
diff --git a/packages/astro/test/fixtures/astro-markdown/src/pages/no-elements.astro b/packages/astro/test/fixtures/astro-markdown/src/pages/no-elements.astro
new file mode 100644
index 000000000000..d865e9046661
--- /dev/null
+++ b/packages/astro/test/fixtures/astro-markdown/src/pages/no-elements.astro
@@ -0,0 +1,5 @@
+---
+import { Markdown } from 'astro/components';
+---
+
+<Markdown></Markdown>
\ No newline at end of file