MAINT: use findall instead of traverse

src/sphinx_book_theme/__init__.py

@@ -20,6 +20,7 @@
 )
 from .header_buttons.launch import add_launch_buttons
 from .header_buttons.source import add_source_buttons
+from ._compat import findall
 from ._transforms import HandleFootnoteTransform
 
 __version__ = "1.1.2"
@@ -53,7 +54,7 @@ def add_metadata_to_page(app, pagename, templatename, context, doctree):
     # Add a shortened page text to the context using the sections text
     if doctree:
         description = ""
-        for section in doctree.traverse(docutil_nodes.section):
+        for section in findall(doctree, docutil_nodes.section):
             description += section.astext().replace("\n", " ")
         description = description[:160]
         context["page_description"] = description

src/sphinx_book_theme/_compat.py

@@ -0,0 +1,9 @@
+from docutils.nodes import Element
+from typing import Iterator
+
+
+def findall(node: Element, *args, **kwargs) -> Iterator[Element]:
+    # findall replaces traverse in docutils v0.18
+    # note a difference is that findall is an iterator
+    impl = getattr(node, "findall", node.traverse)
+    return iter(impl(*args, **kwargs))

src/sphinx_book_theme/_transforms.py

@@ -4,6 +4,7 @@
 from sphinx import addnodes as sphinx_nodes
 from pydata_sphinx_theme.utils import get_theme_options_dict
 from .nodes import SideNoteNode
+from ._compat import findall
 
 
 class HandleFootnoteTransform(SphinxPostTransform):
@@ -19,10 +20,10 @@ def run(self, **kwargs: Any) -> None:
         # Cycle through footnote references, and move their content next to the
         # reference. This lets us display the reference in the margin,
         # or just below on narrow screens.
-        for ref_node in self.document.traverse(docutil_nodes.footnote_reference):
+        for ref_node in findall(self.document, docutil_nodes.footnote_reference):
             parent = None
             # Each footnote reference should have a single node it points to via `ids`
-            for foot_node in self.document.traverse(docutil_nodes.footnote):
+            for foot_node in findall(self.document, docutil_nodes.footnote):
                 # matching the footnote reference with footnote
                 if (
                     len(foot_node.attributes["backrefs"])