Revert "feat: Add UnionType support to query method"

Author: willmcgugan

src/textual/dom.py

@@ -24,13 +24,6 @@
     overload,
 )
 
-try:
-    from types import UnionType
-    from typing import get_args
-except ImportError:
-    UnionType = None  # Type will not exist in earlier versions
-    get_args = None  # Not needed for earlier versions
-
 import rich.repr
 from rich.highlighter import ReprHighlighter
 from rich.style import Style
@@ -102,9 +95,9 @@ def check_identifiers(description: str, *names: str) -> None:
         description: Description of where identifier is used for error message.
         *names: Identifiers to check.
     """
-    fullmatch = _re_identifier.fullmatch
+    match = _re_identifier.fullmatch
     for name in names:
-        if fullmatch(name) is None:
+        if match(name) is None:
             raise BadIdentifier(
                 f"{name!r} is an invalid {description}; "
                 "identifiers must contain only letters, numbers, underscores, or hyphens, and must not begin with a number."
@@ -1373,52 +1366,22 @@ def query(self, selector: str | None = None) -> DOMQuery[Widget]: ...
         @overload
         def query(self, selector: type[QueryType]) -> DOMQuery[QueryType]: ...
 
-        if UnionType is not None:
-
-            @overload
-            def query(self, selector: UnionType) -> DOMQuery[Widget]: ...
-
     def query(
-        self, selector: str | type[QueryType] | UnionType | None = None
+        self, selector: str | type[QueryType] | None = None
     ) -> DOMQuery[Widget] | DOMQuery[QueryType]:
-        """Query the DOM for children that match a selector or widget type, or a union of widget types.
+        """Query the DOM for children that match a selector or widget type.
 
         Args:
-            selector: A CSS selector, widget type, a union of widget types, or `None` for all nodes.
+            selector: A CSS selector, widget type, or `None` for all nodes.
 
         Returns:
             A query object.
-
-        Raises:
-            TypeError: If any type in a Union is not a Widget subclass.
         """
         from textual.css.query import DOMQuery, QueryType
         from textual.widget import Widget
 
         if isinstance(selector, str) or selector is None:
             return DOMQuery[Widget](self, filter=selector)
-        elif UnionType is not None and isinstance(selector, UnionType):
-            # Get all types from the union, including nested unions
-            def get_all_types(union_type):
-                types = set()
-                for t in get_args(union_type):
-                    if isinstance(t, UnionType):
-                        types.update(get_all_types(t))
-                    else:
-                        types.add(t)
-                return types
-
-            # Validate all types in the union are Widget subclasses
-            types_in_union = get_args(selector)
-            if not all(
-                isinstance(t, type) and issubclass(t, Widget) for t in types_in_union
-            ):
-                raise TypeError("All types in Union must be Widget subclasses")
-
-            # Convert Union type to comma-separated string of class names
-            type_names = [t.__name__ for t in types_in_union]
-            selector_str = ", ".join(type_names)
-            return DOMQuery[Widget](self, filter=selector_str)
         else:
             return DOMQuery[QueryType](self, filter=selector.__name__)
 

tests/test_dom.py

@@ -1,10 +1,7 @@
 import pytest
 
-from textual.app import App
 from textual.css.errors import StyleValueError
 from textual.dom import BadIdentifier, DOMNode
-from textual.widget import Widget
-from textual.widgets import Input, Select, Static
 
 
 def test_display_default():
@@ -283,78 +280,3 @@ def test_id_validation(identifier: str):
     """Regression tests for https://github.com/Textualize/textual/issues/3954."""
     with pytest.raises(BadIdentifier):
         DOMNode(id=identifier)
-
-
-class SimpleApp(App):
-    def compose(self):
-        yield Input(id="input1")
-        yield Select([], id="select1")
-        yield Static("Hello", id="static1")
-        yield Input(id="input2")
-
-
-async def test_query_union_type():
-    # Test with a UnionType
-    simple_app = SimpleApp()
-    async with simple_app.run_test():
-        results = simple_app.query(Input | Select)
-        assert len(results) == 3
-        assert {w.id for w in results} == {"input1", "select1", "input2"}
-
-        # Test with a single type
-        results2 = simple_app.query(Input)
-        assert len(results2) == 2
-        assert {w.id for w in results2} == {"input1", "input2"}
-
-        # Test with string selector
-        results3 = simple_app.query("#input1")
-        assert len(results3) == 1
-        assert results3[0].id == "input1"
-
-
-async def test_query_nested_unions():
-    """Test handling of nested unions."""
-
-    simple_app = SimpleApp()
-    async with simple_app.run_test():
-        # Create nested union types
-        InputOrSelect = Input | Select
-        InputSelectOrStatic = InputOrSelect | Static
-
-        # Test nested union query
-        results = simple_app.query(InputSelectOrStatic)
-
-        # Verify that we find all our explicitly defined widgets
-        widget_ids = {w.id for w in results if w.id is not None}
-        expected_ids = {"input1", "select1", "static1", "input2"}
-        assert expected_ids.issubset(widget_ids), "Not all expected widgets were found"
-
-        # Verify we get the right types of widgets
-        assert all(
-            isinstance(w, (Input, Select, Static)) for w in results
-        ), "Found unexpected widget types"
-
-        # Verify each expected widget appears exactly once
-        for expected_id in expected_ids:
-            matching_widgets = [w for w in results if w.id == expected_id]
-            assert (
-                len(matching_widgets) == 1
-            ), f"Widget with id {expected_id} should appear exactly once"
-
-
-async def test_query_empty_union():
-    """Test querying with empty or invalid unions."""
-
-    class AnotherWidget(Widget):
-        pass
-
-    simple_app = SimpleApp()
-    async with simple_app.run_test():
-
-        # Test with a type that exists but has no matches
-        results = simple_app.query(AnotherWidget)
-        assert len(results) == 0
-
-        # Test with widget union that has no matches
-        results = simple_app.query(AnotherWidget | AnotherWidget)
-        assert len(results) == 0