Fix typing component generation & explicitize_args

CHANGELOG.md

@@ -8,6 +8,7 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 - [#3278](https://github.com/plotly/dash/pull/3278) Fix loading selector with children starting at the same digit. Fix [#3276](https://github.com/plotly/dash/issues/3276)
 - [#3280](https://github.com/plotly/dash/pull/3280) Remove flask typing import not available in earlier versions.
 - [#3284](https://github.com/plotly/dash/pull/3284) Fix component as props having the same key when used in the same container.
+- [#3287](https://github.com/plotly/dash/pull/3287) Fix typing component generation & explicitize_args.
 
 ## [3.0.3] - 2025-04-14
 

dash/development/_py_components_generation.py

@@ -22,13 +22,21 @@
 import_string = """# AUTO GENERATED FILE - DO NOT EDIT
 
 import typing  # noqa: F401
-import numbers # noqa: F401
 from typing_extensions import TypedDict, NotRequired, Literal # noqa: F401
-from dash.development.base_component import Component
-try:
-    from dash.development.base_component import ComponentType # noqa: F401
-except ImportError:
-    ComponentType = typing.TypeVar("ComponentType", bound=Component)
+from dash.development.base_component import Component, _explicitize_args
+{custom_imports}
+ComponentType = typing.Union[
+    str,
+    int,
+    float,
+    Component,
+    None,
+    typing.Sequence[typing.Union[str, int, float, Component, None]],
+]
+
+NumberType = typing.Union[
+    typing.SupportsFloat, typing.SupportsInt, typing.SupportsComplex
+]
 
 
 """
@@ -80,7 +88,6 @@ def generate_class_string(
     _namespace = '{namespace}'
     _type = '{typename}'
 {shapes}
-    _explicitize_dash_init = True
 
     def __init__(
         self,
@@ -98,6 +105,8 @@ def __init__(
         args = {args}
         {required_validation}
         super({typename}, self).__init__({argtext})
+
+setattr({typename}, "__init__", _explicitize_args({typename}.__init__))
 '''
 
     filtered_props = (
@@ -239,7 +248,6 @@ def generate_class_file(
     Returns
     -------
     """
-    imports = import_string
 
     class_string = generate_class_string(
         typename,
@@ -255,8 +263,11 @@ def generate_class_file(
     custom_imp = custom_imp.get(typename) or custom_imp.get("*")
 
     if custom_imp:
-        imports += "\n".join(custom_imp)
-        imports += "\n\n"
+        imports = import_string.format(
+            custom_imports="\n" + "\n".join(custom_imp) + "\n\n"
+        )
+    else:
+        imports = import_string.format(custom_imports="")
 
     file_name = f"{typename:s}.py"
 
@@ -321,6 +332,9 @@ def generate_class(
         "TypedDict": TypedDict,
         "NotRequired": NotRequired,
         "Literal": Literal,
+        "NumberType": typing.Union[
+            typing.SupportsFloat, typing.SupportsComplex, typing.SupportsInt
+        ],
     }
     # pylint: disable=exec-used
     exec(string, scope)

dash/development/_py_prop_typing.py

@@ -183,16 +183,10 @@ def get_prop_typing(
     "exact": generate_shape,
     "string": generate_type("str"),
     "bool": generate_type("bool"),
-    "number": generate_type(
-        "typing.Union[typing.SupportsFloat, typing.SupportsInt, typing.SupportsComplex]"
-    ),
-    "node": generate_type(
-        "typing.Union[str, int, float, ComponentType,"
-        " typing.Sequence[typing.Union"
-        "[str, int, float, ComponentType]]]"
-    ),
+    "number": generate_type("NumberType"),
+    "node": generate_type("ComponentType"),
     "func": generate_any,
-    "element": generate_type("ComponentType"),
+    "element": generate_type("Component"),
     "union": generate_union,
     "any": generate_any,
     "custom": generate_any,

dash/development/base_component.py

@@ -57,6 +57,9 @@ def __new__(mcs, name, bases, attributes):
             # We only want to patch the new generated component without
             # the `@_explicitize_args` decorator for mypy support
             # See issue: https://github.com/plotly/dash/issues/3226
+            # Only for component that were generated by 3.0.3
+            # Better to setattr on the component afterwards to ensure
+            # backward compatibility.
             attributes["__init__"] = _explicitize_args(attributes["__init__"])
 
         _component = abc.ABCMeta.__new__(mcs, name, bases, attributes)
@@ -441,7 +444,15 @@ def _validate_deprecation(self):
             warnings.warn(DeprecationWarning(textwrap.dedent(deprecation_message)))
 
 
-ComponentType = typing.TypeVar("ComponentType", bound=Component)
+# Renderable node type.
+ComponentType = typing.Union[
+    str,
+    int,
+    float,
+    Component,
+    None,
+    typing.Sequence[typing.Union[str, int, float, Component, None]],
+]
 
 ComponentTemplate = typing.TypeVar("ComponentTemplate")
 

requirements/ci.txt

@@ -19,3 +19,4 @@ xlrd>=2.0.1
 pytest-rerunfailures
 jupyterlab<4.0.0
 pyright==1.1.398;python_version>="3.7"
+mypy==1.15.0;python_version>="3.12"

tests/integration/test_typing.py

@@ -11,11 +11,55 @@
 t = TypeScriptComponent({0})
 """
 
+basic_app_template = """
+from dash import Dash, html, dcc, callback, Input, Output
 
-def run_pyright(codefile: str):
+app = Dash()
+
+{0}
+app.layout = {1}
+
+@callback(Output("out", "children"), Input("btn", "n_clicks"))
+def on_click() -> html.Div:
+    return {2}
+"""
+
+valid_layout = """html.Div([
+    html.H2('Valid'),
+    'String in middle',
+    123,
+    404.4,
+    dcc.Input(value='', id='in')
+])
+"""
+valid_layout_list = """[
+    html.H2('Valid'),
+    'String in middle',
+    123,
+    404.4,
+    dcc.Input(value='', id='in')
+]
+"""
+valid_layout_function = """
+def layout() -> html.Div:
+    return html.Div(["hello layout"])
+
+"""
+
+invalid_layout = """html.Div([
+    {"invalid": "dictionary in children"}
+])
+"""
+# There is not invalid layout for function & list as explicitly typed as Any to avoid special cases.
+
+valid_callback = "html.Div('Valid')"
+invalid_callback = "[]"
+
+
+def run_module(codefile: str, module: str, extra: str = ""):
 
     cmd = shlex.split(
-        f"pyright {codefile}",
+        f"{sys.executable} -m {module} {codefile}{extra}",
         posix=sys.platform != "win32",
         comments=True,
     )
@@ -32,17 +76,51 @@ def run_pyright(codefile: str):
     return out.decode(), err.decode(), proc.poll()
 
 
-def assert_pyright_output(
-    codefile: str, expected_outputs=tuple(), expected_errors=tuple(), expected_status=0
+def assert_output(
+    codefile: str,
+    code: str,
+    expected_outputs=tuple(),
+    expected_errors=tuple(),
+    expected_status=0,
+    module="pyright",
 ):
-    output, error, status = run_pyright(codefile)
+    output, error, status = run_module(codefile, module)
     assert (
         status == expected_status
-    ), f"Status: {status}\nOutput: {output}\nError: {error}"
+    ), f"Status: {status}\nOutput: {output}\nError: {error}\nCode: {code}"
     for ex_out in expected_outputs:
-        assert ex_out in output, f"Invalid output:\n {output}"
-    for ex_err in expected_errors:
-        assert ex_err in error
+        assert ex_out in output, f"Invalid output:\n {output}\n\nCode: {code}"
+
+
+def format_template_and_save(template, filename, *args):
+    formatted = template.format(*args)
+    with open(filename, "w") as f:
+        f.write(formatted)
+    return formatted
+
+
+def expect(status=None, outputs=None, modular=False):
+    data = {}
+    if status is not None:
+        data["expected_status"] = status
+    if outputs is not None:
+        data["expected_outputs"] = outputs
+    if modular:
+        # The expectations are per module.
+        data["modular"] = modular
+    return data
+
+
+@pytest.fixture()
+def change_dir():
+    original_dir = os.getcwd()
+
+    def change(dirname):
+        os.chdir(dirname)
+
+    yield change
+
+    os.chdir(original_dir)
 
 
 @pytest.mark.parametrize(
@@ -205,7 +283,7 @@ def assert_pyright_output(
                 "expected_status": 1,
                 "expected_outputs": [
                     'Argument of type "tuple[Literal[1], Literal[2]]" cannot be assigned '
-                    'to parameter "a_tuple" of type "Tuple[SupportsFloat | SupportsInt | SupportsComplex, str] | None'
+                    'to parameter "a_tuple" of type "Tuple[NumberType, str] | None'
                 ],
             },
         ),
@@ -247,9 +325,35 @@ def assert_pyright_output(
         ),
     ],
 )
-def test_component_typing(arguments, assertions, tmp_path):
+def test_typi001_component_typing(arguments, assertions, tmp_path):
     codefile = os.path.join(tmp_path, "code.py")
-    with open(codefile, "w") as f:
-        f.write(component_template.format(arguments))
+    code = format_template_and_save(component_template, codefile, arguments)
+    assert_output(codefile, code, module="pyright", **assertions)
+
+
+typing_modules = ["pyright"]
+
+if sys.version_info.minor >= 10:
+    typing_modules.append("mypy")
 
-    assert_pyright_output(codefile, **assertions)
+
+@pytest.mark.parametrize("typing_module", typing_modules)
+@pytest.mark.parametrize(
+    "prelayout, layout, callback_return, assertions",
+    [
+        ("", valid_layout, valid_callback, expect(status=0)),
+        ("", valid_layout_list, valid_callback, expect(status=0)),
+        (valid_layout_function, "layout", valid_callback, expect(status=0)),
+        ("", valid_layout, invalid_callback, expect(status=1)),
+        ("", invalid_layout, valid_callback, expect(status=1)),
+    ],
+)
+def test_typi002_typing_compliance(
+    typing_module, prelayout, layout, callback_return, assertions, tmp_path, change_dir
+):
+    codefile = os.path.join(tmp_path, "code.py")
+    os.chdir(tmp_path)
+    code = format_template_and_save(
+        basic_app_template, codefile, prelayout, layout, callback_return
+    )
+    assert_output(codefile, code, module=typing_module, **assertions)

tests/unit/development/metadata_test.py

@@ -1,13 +1,21 @@
 # AUTO GENERATED FILE - DO NOT EDIT
 
 import typing  # noqa: F401
-import numbers # noqa: F401
 from typing_extensions import TypedDict, NotRequired, Literal # noqa: F401
-from dash.development.base_component import Component
-try:
-    from dash.development.base_component import ComponentType # noqa: F401
-except ImportError:
-    ComponentType = typing.TypeVar("ComponentType", bound=Component)
+from dash.development.base_component import Component, _explicitize_args
+
+ComponentType = typing.Union[
+    str,
+    int,
+    float,
+    Component,
+    None,
+    typing.Sequence[typing.Union[str, int, float, Component, None]],
+]
+
+NumberType = typing.Union[
+    typing.SupportsFloat, typing.SupportsInt, typing.SupportsComplex
+]
 
 
 class Table(Component):
@@ -109,7 +117,7 @@ class Table(Component):
         "OptionalObjectWithExactAndNestedDescription",
             {
             "color": NotRequired[str],
-            "fontSize": NotRequired[typing.Union[typing.SupportsFloat, typing.SupportsInt, typing.SupportsComplex]],
+            "fontSize": NotRequired[NumberType],
             "figure": NotRequired["OptionalObjectWithExactAndNestedDescriptionFigure"]
         }
     )
@@ -126,30 +134,29 @@ class Table(Component):
         "OptionalObjectWithShapeAndNestedDescription",
             {
             "color": NotRequired[str],
-            "fontSize": NotRequired[typing.Union[typing.SupportsFloat, typing.SupportsInt, typing.SupportsComplex]],
+            "fontSize": NotRequired[NumberType],
             "figure": NotRequired["OptionalObjectWithShapeAndNestedDescriptionFigure"]
         }
     )
 
-    _explicitize_dash_init = True
 
     def __init__(
         self,
-        children: typing.Optional[typing.Union[str, int, float, ComponentType, typing.Sequence[typing.Union[str, int, float, ComponentType]]]] = None,
+        children: typing.Optional[ComponentType] = None,
         optionalArray: typing.Optional[typing.Sequence] = None,
         optionalBool: typing.Optional[bool] = None,
         optionalFunc: typing.Optional[typing.Any] = None,
-        optionalNumber: typing.Optional[typing.Union[typing.SupportsFloat, typing.SupportsInt, typing.SupportsComplex]] = None,
+        optionalNumber: typing.Optional[NumberType] = None,
         optionalObject: typing.Optional[dict] = None,
         optionalString: typing.Optional[str] = None,
         optionalSymbol: typing.Optional[typing.Any] = None,
-        optionalNode: typing.Optional[typing.Union[str, int, float, ComponentType, typing.Sequence[typing.Union[str, int, float, ComponentType]]]] = None,
-        optionalElement: typing.Optional[ComponentType] = None,
+        optionalNode: typing.Optional[ComponentType] = None,
+        optionalElement: typing.Optional[Component] = None,
         optionalMessage: typing.Optional[typing.Any] = None,
         optionalEnum: typing.Optional[Literal["News", "Photos"]] = None,
-        optionalUnion: typing.Optional[typing.Union[str, typing.Union[typing.SupportsFloat, typing.SupportsInt, typing.SupportsComplex], typing.Any]] = None,
-        optionalArrayOf: typing.Optional[typing.Sequence[typing.Union[typing.SupportsFloat, typing.SupportsInt, typing.SupportsComplex]]] = None,
-        optionalObjectOf: typing.Optional[typing.Dict[typing.Union[str, float, int], typing.Union[typing.SupportsFloat, typing.SupportsInt, typing.SupportsComplex]]] = None,
+        optionalUnion: typing.Optional[typing.Union[str, NumberType, typing.Any]] = None,
+        optionalArrayOf: typing.Optional[typing.Sequence[NumberType]] = None,
+        optionalObjectOf: typing.Optional[typing.Dict[typing.Union[str, float, int], NumberType]] = None,
         optionalObjectWithExactAndNestedDescription: typing.Optional["OptionalObjectWithExactAndNestedDescription"] = None,
         optionalObjectWithShapeAndNestedDescription: typing.Optional["OptionalObjectWithShapeAndNestedDescription"] = None,
         optionalAny: typing.Optional[typing.Any] = None,
@@ -168,3 +175,5 @@ def __init__(
         args = {k: _locals[k] for k in _explicit_args if k != 'children'}
 
         super(Table, self).__init__(children=children, **args)
+
+setattr(Table, "__init__", _explicitize_args(Table.__init__))

tests/unit/development/test_generate_class_file.py

@@ -33,7 +33,7 @@ def expected_class_string():
 
 @pytest.fixture
 def component_class_string(make_component_dir):
-    return import_string + generate_class_string(
+    return import_string.format(custom_imports="") + generate_class_string(
         typename="Table",
         props=make_component_dir["props"],
         description=make_component_dir["description"],