Build(deps): Update marshmallow requirement from <4,>=3.0.0 to >=3.0.0,<5 (#55)

Updates the requirements on
[marshmallow](https://github.com/marshmallow-code/marshmallow) to permit
the latest version.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a
href="https://github.com/marshmallow-code/marshmallow/blob/dev/CHANGELOG.rst">marshmallow's
changelog</a>.</em></p>
<blockquote>
<p>4.0.0 (2025-04-16)</p>
<hr />
<p>See :ref:<code>upgrading_4_0</code> for a guide on updating your
code.</p>
<p>Features:</p>
<ul>
<li>Typing: Add types to all <code>Field
&lt;marshmallow.fields.Field&gt;</code> constructor kwargs
(:issue:<code>2285</code>).
Thanks :user:<code>navignaw</code> for the suggestion.</li>
<li><code>DateTime &lt;marshmallow.fields.DateTime&gt;</code>,
<code>Date &lt;marshmallow.fields.Date&gt;</code>, <code>Time
&lt;marshmallow.fields.Time&gt;</code>,
<code>TimeDelta &lt;marshmallow.fields.TimeDelta&gt;</code>, and
<code>Enum &lt;marshmallow.fields.Enum&gt;</code>
accept their internal value types as valid input
(:issue:<code>1415</code>).
Thanks :user:<code>bitdancer</code> for the suggestion.</li>
<li><code>@validates &lt;marshmallow.validates&gt;</code> accepts
multiple field names (:issue:<code>1960</code>).
<em>Backwards-incompatible</em>: Decorated methods now receive
<code>data_key</code> as a keyword argument.
Thanks :user:<code>dpriskorn</code> for the suggestion and
:user:<code>dharani7998</code> for the PR.</li>
</ul>
<p>Other changes:</p>
<ul>
<li>
<p>Typing: <code>Field &lt;marshmallow.fields.Field&gt;</code> is now a
generic type with a type argument for the internal value type.</p>
</li>
<li>
<p><code>marshmallow.fields.UUID</code> no longer subclasses
<code>marshmallow.fields.String</code>.</p>
</li>
<li>
<p><code>marshmallow.Schema.load</code> no longer silently fails to call
schema validators when a generator is passed (:issue:<code>1898</code>).
The typing of <code>data</code> is also updated to be more accurate.
Thanks :user:<code>ziplokk1</code> for reporting.</p>
</li>
<li>
<p><em>Backwards-incompatible</em>: Use
<code>datetime.date.fromisoformat</code>,
<code>datetime.time.fromisoformat</code>, and
<code>datetime.datetime.fromisoformat</code> from the standard library
to deserialize dates, times and datetimes (:pr:<code>2078</code>).
As a consequence of this change:</p>
<ul>
<li>Time with time offsets are now supported.</li>
<li>YYYY-MM-DD is now accepted as a datetime and deserialized as naive
00:00 AM.</li>
<li><code>from_iso_date</code>, <code>from_iso_time</code> and
<code>from_iso_datetime</code> are removed from
<code>marshmallow.utils</code>.</li>
</ul>
</li>
<li>
<p>Remove <code>isoformat</code>, <code>to_iso_time</code> and
<code>to_iso_datetime</code> from <code>marshmallow.utils</code>
(:pr:<code>2766</code>).</p>
</li>
<li>
<p>Remove <code>from_rfc</code>, and <code>rfcformat</code> from
<code>marshmallow.utils</code> (:pr:<code>2767</code>).</p>
</li>
<li>
<p>Remove <code>is_keyed_tuple</code> from
<code>marshmallow.utils</code> (:pr:<code>2768</code>).</p>
</li>
<li>
<p>Remove <code>get_fixed_timezone</code> from
<code>marshmallow.utils</code> (:pr:<code>2773</code>).</p>
</li>
<li>
<p><em>Backwards-incompatible</em>:
<code>marshmallow.fields.Boolean</code> no longer serializes non-boolean
values (:pr:<code>2725</code>).</p>
</li>
<li>
<p><em>Backwards-incompatible</em>: Rename <code>schema</code> parameter
to <code>parent</code> in
<code>marshmallow.fields.Field._bind_to_schema</code>
(:issue:<code>1360</code>).</p>
</li>
<li>
<p><em>Backwards-incompatible</em>: Rename <code>pass_many</code>
parameter to <code>pass_collection</code> in pre/post processing methods
(:issue:<code>1369</code>).</p>
</li>
<li>
<p><em>Backwards-incompatible</em>:
<code>marshmallow.fields.TimeDelta</code> no longer truncates float
values when
deserializing (:pr:<code>2654</code>). This allows microseconds to be
preserved, e.g.</p>
</li>
</ul>
<p>.. code-block:: python</p>
<pre><code>from marshmallow import fields
<p>field = fields.TimeDelta()</p>
<h1>Before</h1>
<p>field.deserialize(12.9)
datetime.timedelta(seconds=12)</p>
<h1>datetime.timedelta(seconds=12)</h1>
<p></code></pre></p>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a
href="https://github.com/marshmallow-code/marshmallow/commit/84b15960272c16525c945ae99749e505310612a9"><code>84b1596</code></a>
Bump version and update changelog</li>
<li><a
href="https://github.com/marshmallow-code/marshmallow/commit/a715b9e4bde6c46769e8819faa21649ebec937b6"><code>a715b9e</code></a>
Bump sphinx-issues from 5.0.0 to 5.0.1 (<a
href="https://redirect.github.com/marshmallow-code/marshmallow/issues/2819">#2819</a>)</li>
<li><a
href="https://github.com/marshmallow-code/marshmallow/commit/5c136b11f90f130d321ee2985bb7aaa764258fb9"><code>5c136b1</code></a>
[pre-commit.ci] pre-commit autoupdate (<a
href="https://redirect.github.com/marshmallow-code/marshmallow/issues/2817">#2817</a>)</li>
<li><a
href="https://github.com/marshmallow-code/marshmallow/commit/df1daf03fa79aae61f8aaa85de2a16f1ff63a0de"><code>df1daf0</code></a>
Bump sphinxext-opengraph from 0.9.1 to 0.10.0 (<a
href="https://redirect.github.com/marshmallow-code/marshmallow/issues/2818">#2818</a>)</li>
<li><a
href="https://github.com/marshmallow-code/marshmallow/commit/2fc8207da9cf0cf1d9b9b4ab76d4d0478b588325"><code>2fc8207</code></a>
<a href="https://github.com/validates"><code>@​validates</code></a>
accepts multiple field names (<a
href="https://redirect.github.com/marshmallow-code/marshmallow/issues/1965">#1965</a>)</li>
<li><a
href="https://github.com/marshmallow-code/marshmallow/commit/b7026f3b2622cffc981588b647526fa9525f063d"><code>b7026f3</code></a>
Bump sphinx from 8.1.3 to 8.2.3</li>
<li><a
href="https://github.com/marshmallow-code/marshmallow/commit/c495e525aeff224bf14c2996f5aecf84e4a1ed5b"><code>c495e52</code></a>
[pre-commit.ci] pre-commit autoupdate</li>
<li><a
href="https://github.com/marshmallow-code/marshmallow/commit/f0c6afb430a6d032300658c898752d6c7732b188"><code>f0c6afb</code></a>
Add missing fields to <strong>all</strong> (<a
href="https://redirect.github.com/marshmallow-code/marshmallow/issues/2809">#2809</a>)</li>
<li><a
href="https://github.com/marshmallow-code/marshmallow/commit/ef06fbe2e51ab6f1626c758098d4fc6ecdd8368a"><code>ef06fbe</code></a>
[pre-commit.ci] pre-commit autoupdate (<a
href="https://redirect.github.com/marshmallow-code/marshmallow/issues/2808">#2808</a>)</li>
<li><a
href="https://github.com/marshmallow-code/marshmallow/commit/ffedbfee649d96fad7393a9cdf5ceb5118965631"><code>ffedbfe</code></a>
Merge branch '3.x-line' into dev</li>
<li>Additional commits viewable in <a
href="https://github.com/marshmallow-code/marshmallow/compare/3.0.0...4.0.0">compare
view</a></li>
</ul>
</details>
<br />

You can trigger a rebase of this PR by commenting `@dependabot rebase`.

[//]: # (dependabot-automerge-start)
[//]: # (dependabot-automerge-end)

---

<details>
<summary>Dependabot commands and options</summary>
<br />

You can trigger Dependabot actions by commenting on this PR:
- `@dependabot rebase` will rebase this PR
- `@dependabot recreate` will recreate this PR, overwriting any edits
that have been made to it
- `@dependabot merge` will merge this PR after your CI passes on it
- `@dependabot squash and merge` will squash and merge this PR after
your CI passes on it
- `@dependabot cancel merge` will cancel a previously requested merge
and block automerging
- `@dependabot reopen` will reopen this PR if it is closed
- `@dependabot close` will close this PR and stop Dependabot recreating
it. You can achieve the same result by closing it manually
- `@dependabot show <dependency name> ignore conditions` will show all
of the ignore conditions of the specified dependency
- `@dependabot ignore this major version` will close this PR and stop
Dependabot creating any more for this major version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this minor version` will close this PR and stop
Dependabot creating any more for this minor version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this dependency` will close this PR and stop
Dependabot creating any more for this dependency (unless you reopen the
PR or upgrade to it yourself)

</details>

> **Note**
> Automatic rebases have been disabled on this pull request as it has
been open for over 30 days.

Author: llucax

pyproject.toml

@@ -85,7 +85,7 @@ dev-pytest = [
 ]
 
 marshmallow = [
-  "marshmallow >= 3.0.0, < 4",
+  "marshmallow >= 3.0.0, < 5",
   "marshmallow-dataclass >= 8.0.0, < 9",
 ]
 

src/frequenz/quantities/experimental/marshmallow.py

@@ -14,9 +14,11 @@
     even in minor or patch releases.
 """
 
+from contextvars import ContextVar
 from typing import Any, Type
 
-from marshmallow import Schema, ValidationError, fields
+from marshmallow import Schema, ValidationError
+from marshmallow.fields import Field
 
 from .._apparent_power import ApparentPower
 from .._current import Current
@@ -29,8 +31,20 @@
 from .._temperature import Temperature
 from .._voltage import Voltage
 
+serialize_as_string_default: ContextVar[bool] = ContextVar(
+    "serialize_as_string_default", default=False
+)
+"""Context variable to control the default serialization format for quantities.
 
-class _QuantityField(fields.Field):
+If True, quantities are serialized as strings with units.
+If False, quantities are serialized as floats.
+
+This can be overridden on a per-field basis using the `serialize_as_string`
+metadata attribute.
+"""
+
+
+class _QuantityField(Field[Quantity]):
     """Custom field for Quantity objects supporting per-field serialization configuration.
 
     This class handles serialization and deserialization of ALL Quantity
@@ -57,24 +71,34 @@ class _QuantityField(fields.Field):
     field_type: Type[Quantity] | None = None
     """The specific Quantity subclass."""
 
+    def __init__(self, *args: Any, **kwargs: Any) -> None:
+        """Initialize the field."""
+        self.serialize_as_string_override = kwargs.pop("serialize_as_string", None)
+        super().__init__(*args, **kwargs)
+
     def _serialize(
-        self, value: Quantity, attr: str | None, obj: Any, **kwargs: Any
+        self, value: Quantity | None, attr: str | None, obj: Any, **kwargs: Any
     ) -> Any:
         """Serialize the Quantity object based on per-field configuration."""
         if self.field_type is None or not issubclass(self.field_type, Quantity):
             raise TypeError(
                 "field_type must be set to a Quantity subclass in the subclass."
             )
+        if value is None:
+            return None
 
-        assert self.parent is not None
+        if not isinstance(value, Quantity):
+            raise TypeError(
+                f"Expected a Quantity object, but got {type(value).__name__}."
+            )
 
         # Determine the serialization format
-        default = (
-            False
-            if self.parent.context is None
-            else self.parent.context.get("serialize_as_string_default", False)
+        default = serialize_as_string_default.get()
+        serialize_as_string = (
+            self.serialize_as_string_override
+            if self.serialize_as_string_override is not None
+            else default
         )
-        serialize_as_string = self.metadata.get("serialize_as_string", default)
 
         if serialize_as_string:
             # Use the Quantity's native string representation (includes unit)
@@ -177,7 +201,7 @@ class VoltageField(_QuantityField):
     field_type = Voltage
 
 
-QUANTITY_FIELD_CLASSES: dict[type[Quantity], type[fields.Field]] = {
+QUANTITY_FIELD_CLASSES: dict[type[Quantity], type[Field[Any]]] = {
     ApparentPower: ApparentPowerField,
     Current: CurrentField,
     Energy: EnergyField,
@@ -208,8 +232,10 @@ class QuantitySchema(Schema):
     from marshmallow_dataclass import class_schema
     from marshmallow.validate import Range
     from frequenz.quantities import Percentage
-    from frequenz.quantities.experimental.marshmallow import QuantitySchema
-    from typing import cast
+    from frequenz.quantities.experimental.marshmallow import (
+        QuantitySchema,
+        serialize_as_string_default,
+    )
 
     @dataclass
     class Config:
@@ -245,29 +271,24 @@ class Config:
             },
         )
 
-        @classmethod
-        def load(cls, config: dict[str, Any]) -> "Config":
-            schema = class_schema(cls, base_schema=QuantitySchema)(
-                serialize_as_string_default=True # type: ignore[call-arg]
-            )
-            return cast(Config, schema.load(config))
+    config_obj = Config()
+    Schema = class_schema(Config, base_schema=QuantitySchema)
+    schema = Schema()
+
+    # Default serialization (as float)
+    result = schema.dump(config_obj)
+    assert result["percentage_serialized_as_schema_default"] == 25.0
+
+    # Override default serialization to string
+    serialize_as_string_default.set(True)
+    result = schema.dump(config_obj)
+    assert result["percentage_serialized_as_schema_default"] == "25.0 %"
+    serialize_as_string_default.set(False) # Reset context
+
+    # Per-field configuration always takes precedence
+    assert result["percentage_always_as_string"] == "25.0 %"
+    assert result["percentage_always_as_float"] == 25.0
     ```
     """
 
-    TYPE_MAPPING: dict[type[Quantity], type[fields.Field]] = QUANTITY_FIELD_CLASSES
-
-    def __init__(
-        self, *args: Any, serialize_as_string_default: bool = False, **kwargs: Any
-    ) -> None:
-        """
-        Initialize the schema with a default serialization format.
-
-        Args:
-            *args: Additional positional arguments.
-            serialize_as_string_default: Default serialization format for quantities.
-                If True, quantities are serialized as strings with units.
-                If False, quantities are serialized as floats.
-            **kwargs: Additional keyword arguments.
-        """
-        super().__init__(*args, **kwargs)
-        self.context["serialize_as_string_default"] = serialize_as_string_default
+    TYPE_MAPPING: dict[type, type[Field[Any]]] = QUANTITY_FIELD_CLASSES

tests/experimental/test_marshmallow.py

@@ -18,7 +18,10 @@
     Temperature,
     Voltage,
 )
-from frequenz.quantities.experimental.marshmallow import QuantitySchema
+from frequenz.quantities.experimental.marshmallow import (
+    QuantitySchema,
+    serialize_as_string_default,
+)
 
 
 @dataclass
@@ -74,19 +77,19 @@ class Config:
         default_factory=lambda: Voltage.from_kilovolts(200.0),
         metadata={
             "metadata": {
-                "description": "A voltage field that is always serialized as a string",
-                "serialize_as_string": True,
+                "description": "A voltage field that is always serialized as a string"
             },
+            "serialize_as_string": True,
         },
     )
 
     temp_never_string: Temperature = field(
         default_factory=lambda: Temperature.from_celsius(100.0),
         metadata={
             "metadata": {
-                "description": "A temperature field that is never serialized as a string",
-                "serialize_as_string": False,
+                "description": "A temperature field that is never serialized as a string"
             },
+            "serialize_as_string": False,
         },
     )
 
@@ -96,11 +99,10 @@ def load(cls, config: dict[str, Any]) -> Self:
         schema = class_schema(cls, base_schema=QuantitySchema)()
         return cast(Self, schema.load(config))
 
-    def dump(self, serialize_as_string_default: bool = False) -> dict[str, Any]:
+    def dump(self, use_string: bool = False) -> dict[str, Any]:
         """Dump the configuration."""
-        schema = class_schema(Config, base_schema=QuantitySchema)(
-            serialize_as_string_default=serialize_as_string_default  # type: ignore[call-arg]
-        )
+        schema = class_schema(Config, base_schema=QuantitySchema)()
+        serialize_as_string_default.set(use_string)
         return cast(dict[str, Any], schema.dump(self))
 
 
@@ -208,7 +210,7 @@ def test_config_schema_dump_default_float() -> None:
         temp_never_string=Temperature.from_celsius(10.0),
     )
 
-    dumped = config.dump(serialize_as_string_default=False)
+    dumped = config.dump(use_string=False)
 
     assert dumped == {
         "my_percent_field": 50.0,
@@ -233,7 +235,7 @@ def test_config_schema_dump_default_string() -> None:
         temp_never_string=Temperature.from_celsius(10.0),
     )
 
-    dumped = config.dump(serialize_as_string_default=True)
+    dumped = config.dump(use_string=True)
 
     assert dumped == {
         "my_percent_field": "50 %",