From 18b43eaf9deabb1060ddf8b4bcec252a10beba97 Mon Sep 17 00:00:00 2001
From: Ryan Chandler <ryangjchandler@gmail.com>
Date: Thu, 28 Aug 2025 17:46:33 +0100
Subject: [PATCH 1/2] Fallback to txt when grammar does not exist in CommonMark
 extension

---
 src/Adapters/CommonMark/CodeBlockRenderer.php  |  4 ++++
 ...ack_to_txt_if_the_grammar_doesnt_exist.snap |  2 ++
 .../Adapters/CommonMark/PhikiExtensionTest.php | 18 ++++++++++++++++++
 3 files changed, 24 insertions(+)
 create mode 100644 tests/.pest/snapshots/Adapters/CommonMark/PhikiExtensionTest/it_falls_back_to_txt_if_the_grammar_doesnt_exist.snap

diff --git a/src/Adapters/CommonMark/CodeBlockRenderer.php b/src/Adapters/CommonMark/CodeBlockRenderer.php
index 4ba1917..1f56fe3 100644
--- a/src/Adapters/CommonMark/CodeBlockRenderer.php
+++ b/src/Adapters/CommonMark/CodeBlockRenderer.php
@@ -46,6 +46,10 @@ protected function detectGrammar(FencedCode $node): Grammar|string
 
         preg_match('/[a-zA-Z]+/', $node->getInfoWords()[0], $matches);
 
+        if (! $this->phiki->environment->grammars->has($matches[0])) {
+            return 'txt';
+        }
+
         return $matches[0];
     }
 }
diff --git a/tests/.pest/snapshots/Adapters/CommonMark/PhikiExtensionTest/it_falls_back_to_txt_if_the_grammar_doesnt_exist.snap b/tests/.pest/snapshots/Adapters/CommonMark/PhikiExtensionTest/it_falls_back_to_txt_if_the_grammar_doesnt_exist.snap
new file mode 100644
index 0000000..0dd5421
--- /dev/null
+++ b/tests/.pest/snapshots/Adapters/CommonMark/PhikiExtensionTest/it_falls_back_to_txt_if_the_grammar_doesnt_exist.snap
@@ -0,0 +1,2 @@
+<pre class="phiki github-dark" style="background-color: #24292e;color: #e1e4e8;"><code><span class="line"><span class="token">class A {}
+</span></span></code></pre>
diff --git a/tests/Adapters/CommonMark/PhikiExtensionTest.php b/tests/Adapters/CommonMark/PhikiExtensionTest.php
index 1e6e8f3..b4aed43 100644
--- a/tests/Adapters/CommonMark/PhikiExtensionTest.php
+++ b/tests/Adapters/CommonMark/PhikiExtensionTest.php
@@ -65,3 +65,21 @@ class A {}
 
     expect($generated)->toMatchSnapshot();
 });
+
+it('falls back to txt if the grammar doesnt exist', function () {
+    $environment = new Environment;
+
+    $environment
+        ->addExtension(new CommonMarkCoreExtension)
+        ->addExtension(new PhikiExtension('github-dark'));
+
+    $markdown = new MarkdownConverter($environment);
+
+    $generated = $markdown->convert(<<<'MD'
+    ```nonexistentlang
+    class A {}
+    ```
+    MD);
+
+    expect($generated)->toMatchSnapshot();
+});

From 9600b05b34468f3b3beeb86e2b57f05073b2d38c Mon Sep 17 00:00:00 2001
From: Ryan Chandler <ryangjchandler@gmail.com>
Date: Thu, 28 Aug 2025 17:46:50 +0100
Subject: [PATCH 2/2] Use the Grammar enum instead of magic string

---
 src/Adapters/CommonMark/CodeBlockRenderer.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Adapters/CommonMark/CodeBlockRenderer.php b/src/Adapters/CommonMark/CodeBlockRenderer.php
index 1f56fe3..a177bde 100644
--- a/src/Adapters/CommonMark/CodeBlockRenderer.php
+++ b/src/Adapters/CommonMark/CodeBlockRenderer.php
@@ -41,13 +41,13 @@ public function render(Node $node, ChildNodeRendererInterface $childRenderer)
     protected function detectGrammar(FencedCode $node): Grammar|string
     {
         if (! isset($node->getInfoWords()[0]) || $node->getInfoWords()[0] === '') {
-            return 'txt';
+            return Grammar::Txt;
         }
 
         preg_match('/[a-zA-Z]+/', $node->getInfoWords()[0], $matches);
 
         if (! $this->phiki->environment->grammars->has($matches[0])) {
-            return 'txt';
+            return Grammar::Txt;
         }
 
         return $matches[0];