Fix compatibility with marshmallow>=3.13.0

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## 9.4.0 (unreleased)
+
+Bug fixes:
+
+- Fix compatibility with marshmallow>=3.13.0 
+  so that no DeprecationWarnings are raised ([#224](https://github.com/sloria/environs/issues/224)).
+
 ## 9.3.2 (2021-03-28)
 
 Bug fixes:

azure-pipelines.yml

@@ -31,6 +31,7 @@ jobs:
     parameters:
       toxenvs:
         - lint
+        - py36-marshmallowlowest
         - py36-marshmallow3
         - py37-marshmallow3
         - py38-marshmallow3

environs/__init__.py

@@ -55,6 +55,9 @@ class ParserConflictError(ValueError):
     """Raised when adding a custom parser that conflicts with a built-in parser method."""
 
 
+_SUPPORTS_LOAD_DEFAULT = ma.__version_info__ >= (3, 13)
+
+
 def _field2method(
     field_or_factory: FieldOrFactory, method_name: str, *, preprocess: typing.Optional[typing.Callable] = None
 ) -> ParserMethod:
@@ -63,16 +66,43 @@ def method(
         name: str,
         default: typing.Any = ma.missing,
         subcast: typing.Optional[Subcast] = None,
+        *,
+        # Subset of relevant marshmallow.Field kwargs
+        load_default: typing.Any = ma.missing,
+        missing: typing.Any = ma.missing,
+        validate: typing.Optional[
+            typing.Union[
+                typing.Callable[[typing.Any], typing.Any],
+                typing.Iterable[typing.Callable[[typing.Any], typing.Any]],
+            ]
+        ] = None,
+        required: bool = False,
+        allow_none: typing.Optional[bool] = None,
+        error_messages: typing.Optional[typing.Dict[str, str]] = None,
+        metadata: typing.Optional[typing.Mapping[str, typing.Any]] = None,
         **kwargs,
     ) -> typing.Optional[_T]:
         if self._sealed:
             raise EnvSealedError("Env has already been sealed. New values cannot be parsed.")
-        missing = kwargs.pop("missing", None) or default
+        field_kwargs = dict(
+            validate=validate,
+            required=required,
+            allow_none=allow_none,
+            error_messages=error_messages,
+            metadata=metadata,
+        )
+        if _SUPPORTS_LOAD_DEFAULT:
+            field_kwargs["load_default"] = load_default or default
+        else:
+            field_kwargs["missing"] = missing or default
         if isinstance(field_or_factory, type) and issubclass(field_or_factory, ma.fields.Field):
-            field = field_or_factory(missing=missing, **kwargs)
+            # TODO: Remove `type: ignore` after https://github.com/python/mypy/issues/9676 is fixed
+            field = field_or_factory(**field_kwargs)  # type: ignore
         else:
-            field = field_or_factory(subcast=subcast, missing=missing, **kwargs)
-        parsed_key, value, proxied_key = self._get_from_environ(name, field.missing)
+            field = field_or_factory(subcast=subcast, **field_kwargs)
+        parsed_key, value, proxied_key = self._get_from_environ(
+            name, field.load_default if _SUPPORTS_LOAD_DEFAULT else field.missing
+        )
         self._fields[parsed_key] = field
         source_key = proxied_key or parsed_key
         if value is ma.missing:
@@ -110,7 +140,7 @@ def method(
         if self._sealed:
             raise EnvSealedError("Env has already been sealed. New values cannot be parsed.")
         parsed_key, raw_value, proxied_key = self._get_from_environ(name, default)
-        self._fields[parsed_key] = ma.fields.Field(**kwargs)
+        self._fields[parsed_key] = ma.fields.Field()
         source_key = proxied_key or parsed_key
         if raw_value is ma.missing:
             if self.eager:

setup.py

@@ -1,7 +1,7 @@
 import re
 from setuptools import setup
 
-INSTALL_REQUIRES = ["marshmallow>=2.7.0", "python-dotenv"]
+INSTALL_REQUIRES = ["marshmallow>=3.0.0", "python-dotenv"]
 DJANGO_REQUIRES = ["dj-database-url", "dj-email-url", "django-cache-url"]
 EXTRAS_REQUIRE = {
     "django": DJANGO_REQUIRES,

tests/test_environs.py

@@ -11,6 +11,7 @@
 import dj_email_url
 import django_cache_url
 import pytest
+import marshmallow as ma
 from marshmallow import fields, validate
 
 import environs
@@ -155,7 +156,10 @@ def test_missing_raises_error(self, env):
         assert exc.value.args[0] == 'Environment variable "FOO" not set'
 
     def test_default_set(self, env):
-        assert env.str("FOO", missing="foo") == "foo"
+        if ma.__version_info__ >= (3, 13):
+            assert env.str("FOO", load_default="foo") == "foo"
+        else:
+            assert env.str("FOO", missing="foo") == "foo"
         # Passed positionally
         assert env.str("FOO", "foo") == "foo"
 

tox.ini

@@ -1,13 +1,14 @@
 [tox]
 envlist=
     lint
-    py{36,37,38,39}-marshmallow3
+    py{36,37,38,39}-marshmallow{3,lowest}
     py39-marshmallowdev
 
 [testenv]
 extras = tests
 deps =
-    marshmallow3: marshmallow>=3.0.0a1,<4.0.0
+    marshmallowlowest: marshmallow==3.0.0
+    marshmallow3: marshmallow>=3.0.0,<4.0.0
     marshmallowdev: https://github.com/marshmallow-code/marshmallow/archive/dev.tar.gz
 commands = pytest {posargs}