Add mypy tests for basic use cases of public functions

.github/workflows/nightly.yml

@@ -54,4 +54,20 @@ jobs:
     - name: Run pyright basic on src
       run: pyright --lib tests/annotations/ src/
     - name: (pyright) verify type completeness
-      run: pyright --ignoreexternal --verifytypes hydra_zen
+      run: pyright --ignoreexternal --verifytypes hydra_zen
+
+  run-mypy:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Python 3.8
+      uses: actions/setup-python@v3
+      with:
+        python-version: 3.8
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install mypy
+        pip install -e .
+    - name: Run mypy on test script
+      run: mypy --warn-unused-ignores tests/annotations/mypy_checks.py

.github/workflows/tox_run.yml

@@ -182,4 +182,20 @@ jobs:
     - name: Run pyright basic on src
       run: pyright --lib tests/annotations/ src/
     - name: (pyright) verify type completeness
-      run: pyright --ignoreexternal --verifytypes hydra_zen
+      run: pyright --ignoreexternal --verifytypes hydra_zen
+
+  run-mypy:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Python 3.8
+      uses: actions/setup-python@v3
+      with:
+        python-version: 3.8
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install mypy
+        pip install -e .
+    - name: Run mypy on test script
+      run: mypy --warn-unused-ignores tests/annotations/mypy_checks.py

docs/source/changes.rst

@@ -135,13 +135,13 @@ If you depended on the previous default behavior, you can recreate it by using t
 Improvements
 ------------
 - Adds auto-config support for `dataclasses.dataclass` (as highlighted above). (See :pull:`301`)
+- We now verify that basic use cases of our config-creation and instantiation functions type-check correctly via mypy. Previously, we had only assured type-checking behavior via pyright
 - Adds support for using `builds(<target>, populate_full_signature=True)` where `<target>` is a dataclass type that has a field with a default factory. (See :pull:`299`)
 - Adds auto-config support for `pydantic.Field`, improving hydra-zen's ability to automatically construct configs that describe pydantic models and dataclasses. (See :pull:`303`) 
 - :func:`~hydra_zen.builds` no longer has restrictions on inheritance patterns involving `PartialBuilds`-type configs. (See :pull:`290`)
 - Two new utility functions were added to the public API: :func:`~hydra_zen.is_partial_builds` and :func:`~hydra_zen.uses_zen_processing`
 - The :ref:`automatic type refinement <type-support>` performed by :func:`~hydra_zen.builds` now has enhanced support for ``typing.Annotated``, ``typing.NewType``, and ``typing.TypeVarTuple``. (See :pull:`283`)
 
-
 **Support for New Hydra/OmegaConf Features**
 
 - OmegaConf ``v2.2.1`` added native support for :py:class:`pathlib.Path`. hydra-zen :ref:`already provides support for these <additional-types>`, but will now defer to OmegaConf's native support when possible. (See :pull:`276`)

src/hydra_zen/structured_configs/_implementations.py

@@ -34,7 +34,7 @@
 )
 
 from omegaconf import DictConfig, ListConfig
-from typing_extensions import Final, Literal, ParamSpec, TypeAlias
+from typing_extensions import Final, Literal, ParamSpec, TypeAlias, dataclass_transform
 
 from hydra_zen._compatibility import (
     HYDRA_SUPPORTED_PRIMITIVES,
@@ -176,24 +176,7 @@ def mutable_value(x: _T, *, zen_convert: Optional[ZenConvert] = None) -> _T:
     return field(default_factory=lambda: cast(x))
 
 
-# Alternate form, from PEP proposal:
-# https://github.com/microsoft/pyright/blob/master/specs/dataclass_transforms.md
-#
-# This enables static checkers to work with third-party decorators that create
-# dataclass-like objects
-def __dataclass_transform__(
-    *,
-    eq_default: bool = True,
-    order_default: bool = False,
-    kw_only_default: bool = False,
-    field_descriptors: Tuple[Union[type, Callable[..., Any]], ...] = (()),
-) -> Callable[[_T], _T]:
-    # If used within a stub file, the following implementation can be
-    # replaced with "...".
-    return lambda a: a
-
-
-@__dataclass_transform__()
+@dataclass_transform()
 def hydrated_dataclass(
     target: Callable[..., Any],
     *pos_args: SupportedPrimitive,

tests/annotations/mypy_checks.py

@@ -0,0 +1,68 @@
+# Copyright (c) 2022 Massachusetts Institute of Technology
+# SPDX-License-Identifier: MIT
+from typing import Type
+
+from typing_extensions import assert_type
+
+from hydra_zen import builds, instantiate, make_custom_builds_fn
+
+
+def check_builds() -> None:
+    class A:
+        ...
+
+    def f(x: int) -> str:
+        ...
+
+    assert_type(instantiate(builds(A)), A)
+    assert_type(instantiate(builds(A, populate_full_signature=True)), A)
+    assert_type(instantiate(builds(A, zen_partial=True))(), A)
+
+    assert_type(instantiate(builds(f)), str)
+    assert_type(instantiate(builds(f, populate_full_signature=True)), str)
+    assert_type(instantiate(builds(f, zen_partial=True))(), str)
+
+    builds(f, populate_full_signature=True)(y=2)  # type: ignore [call-arg]
+
+
+def check_make_custom_builds() -> None:
+    class A:
+        ...
+
+    def f(x: int) -> str:
+        ...
+
+    builds_ = make_custom_builds_fn()
+    partial_builds = make_custom_builds_fn(zen_partial=True)
+    full_builds = make_custom_builds_fn(populate_full_signature=True)
+
+    assert_type(instantiate(builds_(A)), A)
+    assert_type(instantiate(full_builds(A)), A)
+    assert_type(instantiate(partial_builds(A))(), A)
+
+    assert_type(instantiate(builds_(f)), str)
+    assert_type(instantiate(full_builds(f)), str)
+    assert_type(instantiate(partial_builds(f))(), str)
+
+    full_builds(f)(y=2)  # type: ignore [call-arg]
+
+
+# def check_just() -> None:
+#     from hydra_zen import just
+
+#     class A:
+#         ...
+
+#     # fails due to: https://github.com/python/mypy/issues/13623
+#     assert_type(instantiate(just(A)), Type[A])
+
+
+## hydrated_dataclass not yet supported: https://github.com/python/mypy/issues/12840
+# def check_hydrated_dataclass() -> None:
+#     from hydra_zen import hydrated_dataclass
+
+#     @hydrated_dataclass(dict)
+#     class A:
+#         x: int
+
+#     assert_type(A(1).x, int)