fix: resolve ty call-top-callable errors on union types

Use isinstance narrowing and cast to avoid callable() checks on union
types containing Mapping, which ty considers potentially callable.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: sciyoshi

prosemirror/model/fragment.py

@@ -92,7 +92,9 @@ def iteratee(
                 ].decode("utf-16-le")
             elif node.is_leaf:
                 if leaf_text:
-                    node_text = leaf_text(node) if callable(leaf_text) else leaf_text
+                    node_text = (
+                        leaf_text if isinstance(leaf_text, str) else leaf_text(node)
+                    )
                 elif (node_leaf_text := node.type.spec.get("leafText")) is not None:
                     node_text = node_leaf_text(node)
                 else:

prosemirror/model/from_dom.py

@@ -811,10 +811,10 @@ def add_element_by_rule(
 
             if isinstance(rule.content_element, str):
                 content_dom = dom_.cssselect(rule.content_element)[0]
-            elif callable(rule.content_element):
-                content_dom = rule.content_element(dom_)
-            elif rule.content_element is not None:
+            elif isinstance(rule.content_element, DOMNode):
                 content_dom = rule.content_element
+            elif rule.content_element is not None:
+                content_dom = rule.content_element(dom_)
 
             self.find_around(dom_, content_dom, True)
             self.add_all(content_dom, marks)

prosemirror/transform/transform.py

@@ -1,6 +1,6 @@
 import re
 from collections.abc import Callable
-from typing import Optional, TypedDict
+from typing import Optional, TypedDict, cast
 
 from prosemirror.model import (
     ContentMatch,
@@ -552,13 +552,18 @@ def set_block_type(
             raise ValueError(msg)
         map_from = len(self.steps)
 
+        get_attrs = cast(
+            "Callable[[Node], Attrs] | None", attrs if callable(attrs) else None
+        )
+        static_attrs = cast("Attrs | None", None if callable(attrs) else attrs)
+
         def iteratee(
             node: "Node",
             pos: int,
             parent: Optional["Node"],
             i: int,
         ) -> bool | None:
-            attrs_here = attrs(node) if callable(attrs) else attrs
+            attrs_here = get_attrs(node) if get_attrs else static_attrs
             if (
                 node.is_textblock
                 and not node.has_markup(type, attrs_here)