Permit another doctype opener that is output on earlier versions of Python.

albu-diku · albu-diku · commit 85f9adbafa64 · 2024-12-23T16:54:24.000+01:00
diff --git a/tests/support/htmlsupp.py b/tests/support/htmlsupp.py
@@ -27,6 +27,12 @@
 
 """Test support library for HTML."""
 
+_POSSIBLE_DOCTYPE_OPENERS =[
+    "<!DOCTYPE HTML",
+    "<!DOCTYPE html",
+    "<!doctype html",
+]
+
 
 class HtmlAssertMixin:
     """Custom assertions for HTML containing strings."""
@@ -58,7 +64,10 @@ def assertIsValidHtmlDocument(self, value, permit_no_close=False):
 
         error = None
         try:
-            has_doctype = value.startswith("<!DOCTYPE html") or value.startswith("<!doctype html")
+            for opener in _POSSIBLE_DOCTYPE_OPENERS:
+                has_doctype = value.startswith(opener)
+                if has_doctype:
+                    break
             assert has_doctype, "no valid document opener"
             end_html_tag_idx = value.rfind('</html>')
             if end_html_tag_idx == -1 and permit_no_close:
