Require marshmallow 4.0

Author: lafrech

.github/workflows/build-release.yml

@@ -13,10 +13,8 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - { name: "3.10", python: "3.10", tox: py310-marshmallow3 }
-          - { name: "3.14", python: "3.14", tox: py314-marshmallow3 }
-          - { name: "3.10", python: "3.10", tox: py310-marshmallow4 }
-          - { name: "3.14", python: "3.14", tox: py314-marshmallow4 }
+          - { name: "3.10", python: "3.10", tox: py310-marshmallow }
+          - { name: "3.14", python: "3.14", tox: py314-marshmallow }
           - { name: "lowest", python: "3.10", tox: py310-lowest }
           - { name: "dev", python: "3.14", tox: py314-marshmallowdev }
     steps:

pyproject.toml

@@ -42,7 +42,7 @@ keywords = [
 ]
 requires-python = ">=3.10"
 dependencies = [
-    "marshmallow>=3.13.0,<5.0.0",
+    "marshmallow>=4.0.0,<5.0.0",
     "packaging>=17.0",
     # depend on typing-extensions conditionally for annotations
     'typing_extensions>=4.0; python_version<"3.10"',

src/webargs/fields.py

@@ -1,7 +1,6 @@
 """Field classes.
 
-Includes all fields from `marshmallow.fields` in addition to a custom
-`Nested` field and `DelimitedList`.
+Includes all fields from `marshmallow.fields` in addition to `DelimitedList`.
 
 All fields can optionally take a special `location` keyword argument, which
 tells webargs where to parse the request argument from.
@@ -26,30 +25,6 @@
 __all__ = ["DelimitedList", "DelimitedTuple"] + ma.fields.__all__
 
 
-# TODO: remove custom `Nested` in the next major release
-#
-# the `Nested` class is only needed on versions of marshmallow prior to v3.15.0
-# in that version, `ma.fields.Nested` gained the ability to consume dict inputs
-# prior to that, this subclass adds this capability
-#
-# if we drop support for ma.__version_info__ < (3, 15) we can do this
-class Nested(ma.fields.Nested):  # type: ignore[no-redef]
-    """Same as `marshmallow.fields.Nested`, except can be passed a dictionary
-    as the first argument, which will be converted to a `marshmallow.Schema`.
-
-    .. note::
-
-        The schema class here will always be `marshmallow.Schema`, regardless
-        of whether a custom schema class is set on the parser. Pass an explicit schema
-        class if necessary.
-    """
-
-    def __init__(self, nested, *args, **kwargs):
-        if isinstance(nested, dict):
-            nested = ma.Schema.from_dict(nested)
-        super().__init__(nested, *args, **kwargs)
-
-
 class DelimitedFieldMixin:
     """
     This is a mixin class for subclasses of ma.fields.List and ma.fields.Tuple

tests/test_core.py

@@ -1,6 +1,5 @@
 import collections
 import datetime
-import importlib.metadata
 import typing
 from unittest import mock
 
@@ -16,15 +15,12 @@
     pre_load,
     validates_schema,
 )
-from packaging.version import Version
 from werkzeug.datastructures import MultiDict as WerkMultiDict
 
 from webargs import ValidationError, fields
 from webargs.core import Parser, get_mimetype, is_json
 from webargs.multidictproxy import MultiDictProxy
 
-MARSHMALLOW_VERSION = Version(importlib.metadata.version("marshmallow"))
-
 
 class MockHTTPError(Exception):
     def __init__(self, status_code, headers):
@@ -557,27 +553,6 @@ def test_required_with_custom_error(parser, web_request):
     assert "We need foo" in excinfo.value.messages["json"]["foo"]
 
 
-@pytest.mark.filterwarnings("ignore:Returning `False` from a validator is deprecated")
-@pytest.mark.skipif(
-    MARSHMALLOW_VERSION.major >= 4,
-    reason="marshmallow 4+ does not support validators returning False",
-)
-def test_required_with_custom_error_and_validation_error(parser, web_request):
-    web_request.json = {"foo": ""}
-    args = {
-        "foo": fields.Str(
-            required="We need foo",
-            validate=lambda s: len(s) > 1,
-            error_messages={"validator_failed": "foo required length is 3"},
-        )
-    }
-    with pytest.raises(ValidationError) as excinfo:
-        # Test that `validate` receives dictionary of args
-        parser.parse(args, web_request)
-
-    assert "foo required length is 3" in excinfo.value.args[0]["foo"]
-
-
 def test_full_input_validator_receives_nonascii_input(web_request):
     def validate(val):
         return False

tox.ini

@@ -1,16 +1,15 @@
 [tox]
 envlist=
     lint
-    py{310,311,312,313,314}-marshmallow{3,4}
+    py{310,311,312,313,314}-marshmallow
     py314-marshmallowdev
     py310-lowest
     docs
 
 [testenv]
 extras = tests
 deps =
-    marshmallow3: marshmallow>=3.0.0,<4.0.0
-    marshmallow4: marshmallow>=4.0.0,<5.0.0
+    marshmallow: marshmallow>=4.0.0,<5.0.0
     marshmallowdev: https://github.com/marshmallow-code/marshmallow/archive/dev.tar.gz
     lowest: flask==3.1.0
     lowest: Django==5.2.0