From 2a56ee8ca3a21405cf0ec22d664b08d4e6cd2549 Mon Sep 17 00:00:00 2001
From: mck09 <mck097@gmail.com>
Date: Sun, 30 Aug 2026 13:14:50 +0200
Subject: [PATCH 1/2] fix: do not add a newline to an empty code block

Renderer.code appended a newline unconditionally, so a code block with no
content rendered as <pre><code>\n</code></pre> instead of
<pre><code></code></pre>.

This fixes CommonMark examples 126, 130, 144 and 237. The spec suite did not
catch it because htmlIsEqual leaves html-differ's ignoreWhitespaces at its
default of true, and whitespace inside pre/code is significant, so all four
were already reported as passing.
---
 src/Renderer.ts          |  3 ++-
 test/unit/marked.test.js | 21 +++++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/Renderer.ts b/src/Renderer.ts
index 890ac2c4ec..c0a308bc36 100644
--- a/src/Renderer.ts
+++ b/src/Renderer.ts
@@ -25,7 +25,8 @@ export class _Renderer<ParserOutput = string, RendererOutput = string> {
   code({ text, lang, escaped }: Tokens.Code): RendererOutput {
     const langString = (lang || '').match(other.notSpaceStart)?.[0];
 
-    const code = text.replace(other.endingNewline, '') + '\n';
+    // An empty code block has no content, so it must not gain a newline.
+    const code = text ? text.replace(other.endingNewline, '') + '\n' : '';
 
     if (!langString) {
       return '<pre><code>'
diff --git a/test/unit/marked.test.js b/test/unit/marked.test.js
index 5d1449b4aa..f1b4ab4c07 100644
--- a/test/unit/marked.test.js
+++ b/test/unit/marked.test.js
@@ -22,6 +22,27 @@ describe('marked unit', () => {
     });
   });
 
+  describe('empty code block', () => {
+    it('should not add a newline to an unclosed empty fence', () => {
+      assert.strictEqual(marked.parse('```\n'), '<pre><code></code></pre>\n');
+    });
+
+    it('should not add a newline to a closed empty fence', () => {
+      assert.strictEqual(marked.parse('```\n```\n'), '<pre><code></code></pre>\n');
+    });
+
+    it('should not add a newline to an empty fence with a language', () => {
+      assert.strictEqual(
+        marked.parse('````;\n````\n'),
+        '<pre><code class="language-;"></code></pre>\n',
+      );
+    });
+
+    it('should keep the content of a non-empty code block', () => {
+      assert.strictEqual(marked.parse('```\nx\n```\n'), '<pre><code>x\n</code></pre>\n');
+    });
+  });
+
   describe('changeDefaults', () => {
     it('should change global defaults', async() => {
       const { defaults, setOptions } = await import('../../lib/marked.esm.js');

From 474ae0556fa75a508ba16a3d79fca902333e56ba Mon Sep 17 00:00:00 2001
From: mck09 <mck097@gmail.com>
Date: Thu, 3 Sep 2026 04:41:48 +0200
Subject: [PATCH 2/2] test: move the empty code block tests to test/specs/new

Uses renderExact so the fixture compares exactly, which htmlIsEqual
does not, and keeps the assertions out of marked.test.js.
---
 test/specs/new/empty_code_block.html |  8 ++++++++
 test/specs/new/empty_code_block.md   | 20 ++++++++++++++++++++
 test/unit/marked.test.js             | 21 ---------------------
 3 files changed, 28 insertions(+), 21 deletions(-)
 create mode 100644 test/specs/new/empty_code_block.html
 create mode 100644 test/specs/new/empty_code_block.md

diff --git a/test/specs/new/empty_code_block.html b/test/specs/new/empty_code_block.html
new file mode 100644
index 0000000000..2dc57fc61e
--- /dev/null
+++ b/test/specs/new/empty_code_block.html
@@ -0,0 +1,8 @@
+<pre><code></code></pre>
+<p>sep</p>
+<pre><code class="language-;"></code></pre>
+<p>sep</p>
+<pre><code>x
+</code></pre>
+<p>sep</p>
+<pre><code></code></pre>
diff --git a/test/specs/new/empty_code_block.md b/test/specs/new/empty_code_block.md
new file mode 100644
index 0000000000..11b7d8b466
--- /dev/null
+++ b/test/specs/new/empty_code_block.md
@@ -0,0 +1,20 @@
+---
+renderExact: true
+---
+```
+```
+
+sep
+
+````;
+````
+
+sep
+
+```
+x
+```
+
+sep
+
+```
diff --git a/test/unit/marked.test.js b/test/unit/marked.test.js
index f1b4ab4c07..5d1449b4aa 100644
--- a/test/unit/marked.test.js
+++ b/test/unit/marked.test.js
@@ -22,27 +22,6 @@ describe('marked unit', () => {
     });
   });
 
-  describe('empty code block', () => {
-    it('should not add a newline to an unclosed empty fence', () => {
-      assert.strictEqual(marked.parse('```\n'), '<pre><code></code></pre>\n');
-    });
-
-    it('should not add a newline to a closed empty fence', () => {
-      assert.strictEqual(marked.parse('```\n```\n'), '<pre><code></code></pre>\n');
-    });
-
-    it('should not add a newline to an empty fence with a language', () => {
-      assert.strictEqual(
-        marked.parse('````;\n````\n'),
-        '<pre><code class="language-;"></code></pre>\n',
-      );
-    });
-
-    it('should keep the content of a non-empty code block', () => {
-      assert.strictEqual(marked.parse('```\nx\n```\n'), '<pre><code>x\n</code></pre>\n');
-    });
-  });
-
   describe('changeDefaults', () => {
     it('should change global defaults', async() => {
       const { defaults, setOptions } = await import('../../lib/marked.esm.js');