fix: Code block language parsing (#1362)

* fix: Code block language parsing

* Small change to code clarity

---------

Co-authored-by: matthewlipski <[email protected]>

Author: areknawo

packages/core/src/api/parsers/html/__snapshots__/parse-codeblocks.json

@@ -0,0 +1,62 @@
+[
+  {
+    "id": "1",
+    "type": "codeBlock",
+    "props": {
+      "language": "javascript"
+    },
+    "content": [
+      {
+        "type": "text",
+        "text": "console.log(\"Should default to JS\")",
+        "styles": {}
+      }
+    ],
+    "children": []
+  },
+  {
+    "id": "2",
+    "type": "codeBlock",
+    "props": {
+      "language": "typescript"
+    },
+    "content": [
+      {
+        "type": "text",
+        "text": "console.log(\"Should parse TS from data-language\")",
+        "styles": {}
+      }
+    ],
+    "children": []
+  },
+  {
+    "id": "3",
+    "type": "codeBlock",
+    "props": {
+      "language": "python"
+    },
+    "content": [
+      {
+        "type": "text",
+        "text": "print(\"Should parse Python from language- class\")",
+        "styles": {}
+      }
+    ],
+    "children": []
+  },
+  {
+    "id": "4",
+    "type": "codeBlock",
+    "props": {
+      "language": "typescript"
+    },
+    "content": [
+      {
+        "type": "text",
+        "text": "console.log(\"Should prioritize TS from data-language over language- class\")",
+        "styles": {}
+      }
+    ],
+    "children": []
+  }
+]

packages/core/src/api/parsers/html/parseHTML.test.ts

@@ -516,4 +516,13 @@ With Hard Break</p>
 
     await parseHTMLAndCompareSnapshots(html, "parse-google-docs-html");
   });
+
+  it("Parse codeblocks", async () => {
+    const html = `<pre><code>console.log("Should default to JS")</code></pre>
+    <pre><code data-language="typescript">console.log("Should parse TS from data-language")</code></pre>
+    <pre><code class="language-python">print("Should parse Python from language- class")</code></pre>
+    <pre><code class="language-ruby" data-language="typescript">console.log("Should prioritize TS from data-language over language- class")</code></pre>`;
+
+    await parseHTMLAndCompareSnapshots(html, "parse-codeblocks");
+  });
 });

packages/core/src/blocks/CodeBlockContent/CodeBlockContent.ts

@@ -77,9 +77,10 @@ const CodeBlockContent = createStronglyTypedTiptapNode({
             const languages = classNames
               .filter((className) => className.startsWith("language-"))
               .map((className) => className.replace("language-", ""));
-            const [classLanguage] = languages;
 
-            language = classLanguage.toLowerCase();
+            if (languages.length > 0) {
+              language = languages[0].toLowerCase();
+            }
           }
 
           if (!language) {