added renderer selection (py-gfm as alternative)

src/markdown_utils.py

@@ -54,9 +54,32 @@ def _promote_headings(text: str) -> str:
     return "\n".join(promoted_lines)
 
 
-def convert_markdown(markdown_text: str, context: str, issues: list[ValidationIssue]) -> str | None:
-    try:
-        return md_lib.markdown(markdown_text, extensions=["extra"], output_format="html5")
-    except Exception as exc:  # pragma: no cover - depends on markdown internals
-        issues.append(ValidationIssue(f"Markdown conversion failed: {exc}", context=context))
-        return None
+def convert_markdown(
+    markdown_text: str,
+    context: str,
+    issues: list[ValidationIssue],
+    renderer: str = "default",
+) -> str | None:
+    if renderer == "default":
+        try:
+            return md_lib.markdown(markdown_text, extensions=["extra"], output_format="html5")
+        except Exception as exc:  # pragma: no cover - depends on markdown internals
+            issues.append(ValidationIssue(f"Markdown conversion failed: {exc}", context=context))
+            return None
+    if renderer == "py-gfm":
+        try:
+            import mdx_gfm
+        except Exception as exc:  # pragma: no cover - dependency missing
+            issues.append(ValidationIssue(f"py-gfm is not available: {exc}", context=context))
+            return None
+        extension_class = getattr(mdx_gfm, "GithubFlavoredMarkdownExtension", None)
+        if extension_class is None:
+            issues.append(ValidationIssue("py-gfm extension not found: GithubFlavoredMarkdownExtension", context=context))
+            return None
+        try:
+            return md_lib.markdown(markdown_text, extensions=[extension_class()], output_format="html5")
+        except Exception as exc:  # pragma: no cover - depends on markdown internals
+            issues.append(ValidationIssue(f"Markdown conversion failed: {exc}", context=context))
+            return None
+    issues.append(ValidationIssue(f"Unknown renderer: {renderer}", context=context))
+    return None