Handle comments and CDATA in HTML formatted text

src/prompt_toolkit/formatted_text/html.py

@@ -54,9 +54,9 @@ def get_current_style() -> str:
         def process_node(node: Any) -> None:
             "Process node recursively."
             for child in node.childNodes:
-                if child.nodeType == child.TEXT_NODE:
+                if child.nodeType in (child.TEXT_NODE, child.CDATA_SECTION_NODE):
                     result.append((get_current_style(), child.data))
-                else:
+                elif child.nodeType == child.ELEMENT_NODE:
                     add_to_name_stack = child.nodeName not in (
                         "#document",
                         "html-root",

tests/test_html_nodes.py

@@ -0,0 +1,50 @@
+from __future__ import annotations
+
+import io
+
+import pytest
+
+from prompt_toolkit import print_formatted_text
+from prompt_toolkit.formatted_text import HTML, to_formatted_text
+
+
+@pytest.mark.parametrize(
+    "markup, expected",
+    [
+        ("<!-- hidden -->", []),
+        ("before<!-- hidden -->after", [("", "before"), ("", "after")]),
+        (
+            "<b>before<!-- <i>hidden</i> -->after</b>",
+            [("class:b", "before"), ("class:b", "after")],
+        ),
+        (
+            '<style fg="ansired"><!-- hidden --><b>text</b></style>after',
+            [("class:b fg:ansired", "text"), ("", "after")],
+        ),
+        ("<?note hidden?>visible", [("", "visible")]),
+        (
+            "<b>before<?note hidden?>after</b>",
+            [("class:b", "before"), ("class:b", "after")],
+        ),
+        ("<![CDATA[a < b & c]]>", [("", "a < b & c")]),
+        (
+            '<b fg="ansired"><![CDATA[<i>literal</i>]]></b>after',
+            [("class:b fg:ansired", "<i>literal</i>"), ("", "after")],
+        ),
+        (
+            "<b>before<![CDATA[ & ]]><!-- hidden -->after</b>",
+            [("class:b", "before"), ("class:b", " & "), ("class:b", "after")],
+        ),
+    ],
+)
+def test_html_non_element_nodes(markup, expected):
+    assert to_formatted_text(HTML(markup)) == expected
+
+
+def test_print_html_with_comments_and_cdata():
+    output = io.StringIO()
+    print_formatted_text(
+        HTML("<b>Result: <!-- internal note --><![CDATA[x < 3]]></b>"),
+        file=output,
+    )
+    assert output.getvalue() == "Result: x < 3\r\n"