feat: improve type for code_language_callback

Author: G-Rath

markdownify/__init__.pyi

@@ -1,4 +1,5 @@
 from _typeshed import Incomplete
+from typing import Callable, Union
 
 ATX: str
 ATX_CLOSED: str
@@ -20,7 +21,7 @@ def markdownify(
     bs4_options: str = ...,
     bullets: str = ...,
     code_language: str = ...,
-    code_language_callback: Incomplete | None = ...,
+    code_language_callback: Callable[[Incomplete], Union[str, None]] | None = ...,
     convert: list[str] | None = ...,
     default_title: bool = ...,
     escape_asterisks: bool = ...,
@@ -48,7 +49,7 @@ class MarkdownConverter:
         bs4_options: str = ...,
         bullets: str = ...,
         code_language: str = ...,
-        code_language_callback: Incomplete | None = ...,
+        code_language_callback: Callable[[Incomplete], Union[str, None]] | None = ...,
         convert: list[str] | None = ...,
         default_title: bool = ...,
         escape_asterisks: bool = ...,

tests/types.py

@@ -55,4 +55,15 @@
 
 html = '<b>test</b>'
 soup = BeautifulSoup(html, 'html.parser')
-MarkdownConverter().convert_soup(soup) == '**test**'
+MarkdownConverter().convert_soup(soup) == '**test**'
+
+
+def callback(el: BeautifulSoup) -> str | None:
+    return el['class'][0] if el.has_attr('class') else None
+
+
+MarkdownConverter(code_language_callback=callback).convert("")
+MarkdownConverter(code_language_callback=lambda el: None).convert("")
+
+markdownify('<pre class="python">test\n    foo\nbar</pre>', code_language_callback=callback)
+markdownify('<pre class="python">test\n    foo\nbar</pre>', code_language_callback=lambda el: None)