Enable custom default config for dataset tests (#3578)

test/datasets_utils.py

@@ -117,19 +117,45 @@ def requires_lazy_imports(*modules):
 def test_all_configs(test):
     """Decorator to run test against all configurations.
 
-    Add this as decorator to an arbitrary test to run it against all configurations. The current configuration is
-    provided as the first parameter:
+    Add this as decorator to an arbitrary test to run it against all configurations. This includes
+    :attr:`DatasetTestCase.DEFAULT_CONFIG` and :attr:`DatasetTestCase.ADDITIONAL_CONFIGS`.
+
+    The current configuration is provided as the first parameter for the test:
 
     .. code-block::
 
-        @test_all_configs
+        @test_all_configs()
         def test_foo(self, config):
             pass
+
+    .. note::
+
+        This will try to remove duplicate configurations. During this process it will not not preserve a potential
+        ordering of the configurations or an inner ordering of a configuration.
     """
 
+    def maybe_remove_duplicates(configs):
+        try:
+            return [dict(config_) for config_ in set(tuple(sorted(config.items())) for config in configs)]
+        except TypeError:
+            # A TypeError will be raised if a value of any config is not hashable, e.g. a list. In that case duplicate
+            # removal would be a lot more elaborate and we simply bail out.
+            return configs
+
     @functools.wraps(test)
     def wrapper(self):
-        for config in self.CONFIGS or (self._DEFAULT_CONFIG,):
+        configs = []
+        if self.DEFAULT_CONFIG is not None:
+            configs.append(self.DEFAULT_CONFIG)
+        if self.ADDITIONAL_CONFIGS is not None:
+            configs.extend(self.ADDITIONAL_CONFIGS)
+
+        if not configs:
+            configs = [self._KWARG_DEFAULTS.copy()]
+        else:
+            configs = maybe_remove_duplicates(configs)
+
+        for config in configs:
             with self.subTest(**config):
                 test(self, config)
 
@@ -166,9 +192,13 @@ class DatasetTestCase(unittest.TestCase):
 
     Optionally, you can overwrite the following class attributes:
 
-        - CONFIGS (Sequence[Dict[str, Any]]): Additional configs that should be tested. Each dictonary can contain an
-            arbitrary combination of dataset parameters that are **not** ``transform``, ``target_transform``,
-            ``transforms``, or ``download``. The first element will be used as default configuration.
+        - DEFAULT_CONFIG (Dict[str, Any]): Config that will be used by default. If omitted, this defaults to all
+            keyword arguments of the dataset minus ``transform``, ``target_transform``, ``transforms``, and
+            ``download``. Overwrite this if you want to use a default value for a parameter for which the dataset does
+            not provide one.
+        - ADDITIONAL_CONFIGS (Sequence[Dict[str, Any]]): Additional configs that should be tested. Each dictionary can
+            contain an arbitrary combination of dataset parameters that are **not** ``transform``, ``target_transform``,
+            ``transforms``, or ``download``.
         - REQUIRED_PACKAGES (Iterable[str]): Additional dependencies to use the dataset. If these packages are not
             available, the tests are skipped.
 
@@ -218,22 +248,31 @@ class DatasetTestCase(unittest.TestCase):
     DATASET_CLASS = None
     FEATURE_TYPES = None
 
-    CONFIGS = None
+    DEFAULT_CONFIG = None
+    ADDITIONAL_CONFIGS = None
     REQUIRED_PACKAGES = None
 
-    _DEFAULT_CONFIG = None
-
+    # These keyword arguments are checked by test_transforms in case they are available in DATASET_CLASS.
     _TRANSFORM_KWARGS = {
         "transform",
         "target_transform",
         "transforms",
     }
+    # These keyword arguments get a 'special' treatment and should not be set in DEFAULT_CONFIG or ADDITIONAL_CONFIGS.
     _SPECIAL_KWARGS = {
         *_TRANSFORM_KWARGS,
         "download",
     }
+
+    # These fields are populated during setupClass() within _populate_private_class_attributes()
+
+    # This will be a dictionary containing all keyword arguments with their respective default values extracted from
+    # the dataset constructor.
+    _KWARG_DEFAULTS = None
+    # This will be a set of all _SPECIAL_KWARGS that the dataset constructor takes.
     _HAS_SPECIAL_KWARG = None
 
+    # These functions are disabled during dataset creation in create_dataset().
     _CHECK_FUNCTIONS = {
         "check_md5",
         "check_integrity",
@@ -256,7 +295,8 @@ class DatasetTestCase(unittest.TestCase):
         Args:
             tmpdir (str): Path to a temporary directory. For most cases this acts as root directory for the dataset
                 to be created and in turn also for the fake data injected here.
-            config (Dict[str, Any]): Configuration that will be used to create the dataset.
+            config (Dict[str, Any]): Configuration that will be passed to the dataset constructor. It provides at least
+                fields for all dataset parameters with default values.
 
         Returns:
             (Tuple[str]): ``tmpdir`` which corresponds to ``root`` for most datasets.
@@ -273,7 +313,8 @@ class DatasetTestCase(unittest.TestCase):
         Args:
             tmpdir (str): Path to a temporary directory. For most cases this acts as root directory for the dataset
                 to be created and in turn also for the fake data injected here.
-            config (Dict[str, Any]): Configuration that will be used to create the dataset.
+            config (Dict[str, Any]): Configuration that will be passed to the dataset constructor. It provides at least
+                fields for all dataset parameters with default values.
 
         Needs to return one of the following:
 
@@ -293,9 +334,16 @@ class DatasetTestCase(unittest.TestCase):
     ) -> Iterator[Tuple[torchvision.datasets.VisionDataset, Dict[str, Any]]]:
         r"""Create the dataset in a temporary directory.
 
+        The configuration passed to the dataset is populated to contain at least all parameters with default values.
+        For this the following order of precedence is used:
+
+        1. Parameters in :attr:`kwargs`.
+        2. Configuration in :attr:`config`.
+        3. Configuration in :attr:`~DatasetTestCase.DEFAULT_CONFIG`.
+        4. Default parameters of the dataset.
+
         Args:
-            config (Optional[Dict[str, Any]]): Configuration that will be used to create the dataset. If omitted, the
-                default configuration is used.
+            config (Optional[Dict[str, Any]]): Configuration that will be used to create the dataset.
             inject_fake_data (bool): If ``True`` (default) inject the fake data with :meth:`.inject_fake_data` before
                 creating the dataset.
             patch_checks (Optional[bool]): If ``True`` disable integrity check logic while creating the dataset. If
@@ -308,30 +356,33 @@ class DatasetTestCase(unittest.TestCase):
             info (Dict[str, Any]): Additional information about the injected fake data. See :meth:`.inject_fake_data`
                 for details.
         """
-        default_config = self._DEFAULT_CONFIG.copy()
-        if config is not None:
-            default_config.update(config)
-        config = default_config
-
         if patch_checks is None:
             patch_checks = inject_fake_data
 
         special_kwargs, other_kwargs = self._split_kwargs(kwargs)
+
+        complete_config = self._KWARG_DEFAULTS.copy()
+        if self.DEFAULT_CONFIG:
+            complete_config.update(self.DEFAULT_CONFIG)
+        if config:
+            complete_config.update(config)
+        if other_kwargs:
+            complete_config.update(other_kwargs)
+
         if "download" in self._HAS_SPECIAL_KWARG and special_kwargs.get("download", False):
             # override download param to False param if its default is truthy
             special_kwargs["download"] = False
-        config.update(other_kwargs)
 
         patchers = self._patch_download_extract()
         if patch_checks:
             patchers.update(self._patch_checks())
 
         with get_tmp_dir() as tmpdir:
-            args = self.dataset_args(tmpdir, config)
-            info = self._inject_fake_data(tmpdir, config) if inject_fake_data else None
+            args = self.dataset_args(tmpdir, complete_config)
+            info = self._inject_fake_data(tmpdir, complete_config) if inject_fake_data else None
 
             with self._maybe_apply_patches(patchers), disable_console_output():
-                dataset = self.DATASET_CLASS(*args, **config, **special_kwargs)
+                dataset = self.DATASET_CLASS(*args, **complete_config, **special_kwargs)
 
             yield dataset, info
 
@@ -357,26 +408,69 @@ class DatasetTestCase(unittest.TestCase):
 
     @classmethod
     def _populate_private_class_attributes(cls):
-        argspec = inspect.getfullargspec(cls.DATASET_CLASS.__init__)
+        defaults = []
+        for cls_ in cls.DATASET_CLASS.__mro__:
+            if cls_ is torchvision.datasets.VisionDataset:
+                break
 
-        cls._DEFAULT_CONFIG = {
-            kwarg: default
-            for kwarg, default in zip(argspec.args[-len(argspec.defaults):], argspec.defaults)
-            if kwarg not in cls._SPECIAL_KWARGS
-        }
+            argspec = inspect.getfullargspec(cls_.__init__)
 
-        cls._HAS_SPECIAL_KWARG = {name for name in cls._SPECIAL_KWARGS if name in argspec.args}
+            if not argspec.defaults:
+                continue
+
+            defaults.append(
+                {kwarg: default for kwarg, default in zip(argspec.args[-len(argspec.defaults):], argspec.defaults)}
+            )
+
+            if not argspec.varkw:
+                break
+
+        kwarg_defaults = dict()
+        for config in reversed(defaults):
+            kwarg_defaults.update(config)
+
+        has_special_kwargs = set()
+        for name in cls._SPECIAL_KWARGS:
+            if name not in kwarg_defaults:
+                continue
+
+            del kwarg_defaults[name]
+            has_special_kwargs.add(name)
+
+        cls._KWARG_DEFAULTS = kwarg_defaults
+        cls._HAS_SPECIAL_KWARG = has_special_kwargs
 
     @classmethod
     def _process_optional_public_class_attributes(cls):
-        if cls.REQUIRED_PACKAGES is not None:
-            try:
+        def check_config(config, name):
+            special_kwargs = tuple(f"'{name}'" for name in cls._SPECIAL_KWARGS if name in config)
+            if special_kwargs:
+                raise UsageError(
+                    f"{name} contains a value for the parameter(s) {', '.join(special_kwargs)}. "
+                    f"These are handled separately by the test case and should not be set here. "
+                    f"If you need to test some custom behavior regarding these parameters, "
+                    f"you need to write a custom test (*not* test case), e.g. test_custom_transform()."
+                )
+
+        if cls.DEFAULT_CONFIG is not None:
+            check_config(cls.DEFAULT_CONFIG, "DEFAULT_CONFIG")
+
+        if cls.ADDITIONAL_CONFIGS is not None:
+            for idx, config in enumerate(cls.ADDITIONAL_CONFIGS):
+                check_config(config, f"CONFIGS[{idx}]")
+
+        if cls.REQUIRED_PACKAGES:
+            missing_pkgs = []
             for pkg in cls.REQUIRED_PACKAGES:
+                try:
                     importlib.import_module(pkg)
-            except ImportError as error:
+                except ImportError:
+                    missing_pkgs.append(f"'{pkg}'")
+
+            if missing_pkgs:
                 raise unittest.SkipTest(
-                    f"The package '{error.name}' is required to load the dataset '{cls.DATASET_CLASS.__name__}' but is "
-                    f"not installed."
+                    f"The package(s) {', '.join(missing_pkgs)} are required to load the dataset "
+                    f"'{cls.DATASET_CLASS.__name__}', but are not installed."
                 )
 
     def _split_kwargs(self, kwargs):

test/test_datasets.py

@@ -369,7 +369,9 @@ class Caltech101TestCase(datasets_utils.ImageDatasetTestCase):
     DATASET_CLASS = datasets.Caltech101
     FEATURE_TYPES = (PIL.Image.Image, (int, np.ndarray, tuple))
 
-    CONFIGS = datasets_utils.combinations_grid(target_type=("category", "annotation", ["category", "annotation"]))
+    ADDITIONAL_CONFIGS = datasets_utils.combinations_grid(
+        target_type=("category", "annotation", ["category", "annotation"])
+    )
     REQUIRED_PACKAGES = ("scipy",)
 
     def inject_fake_data(self, tmpdir, config):
@@ -466,7 +468,7 @@ class Caltech256TestCase(datasets_utils.ImageDatasetTestCase):
 class WIDERFaceTestCase(datasets_utils.ImageDatasetTestCase):
     DATASET_CLASS = datasets.WIDERFace
     FEATURE_TYPES = (PIL.Image.Image, (dict, type(None)))  # test split returns None as target
-    CONFIGS = datasets_utils.combinations_grid(split=('train', 'val', 'test'))
+    ADDITIONAL_CONFIGS = datasets_utils.combinations_grid(split=('train', 'val', 'test'))
 
     def inject_fake_data(self, tmpdir, config):
         widerface_dir = pathlib.Path(tmpdir) / 'widerface'
@@ -521,7 +523,7 @@ class WIDERFaceTestCase(datasets_utils.ImageDatasetTestCase):
 class ImageNetTestCase(datasets_utils.ImageDatasetTestCase):
     DATASET_CLASS = datasets.ImageNet
     REQUIRED_PACKAGES = ('scipy',)
-    CONFIGS = datasets_utils.combinations_grid(split=('train', 'val'))
+    ADDITIONAL_CONFIGS = datasets_utils.combinations_grid(split=('train', 'val'))
 
     def inject_fake_data(self, tmpdir, config):
         tmpdir = pathlib.Path(tmpdir)
@@ -551,7 +553,7 @@ class ImageNetTestCase(datasets_utils.ImageDatasetTestCase):
 
 class CIFAR10TestCase(datasets_utils.ImageDatasetTestCase):
     DATASET_CLASS = datasets.CIFAR10
-    CONFIGS = datasets_utils.combinations_grid(train=(True, False))
+    ADDITIONAL_CONFIGS = datasets_utils.combinations_grid(train=(True, False))
 
     _VERSION_CONFIG = dict(
         base_folder="cifar-10-batches-py",
@@ -623,7 +625,7 @@ class CelebATestCase(datasets_utils.ImageDatasetTestCase):
     DATASET_CLASS = datasets.CelebA
     FEATURE_TYPES = (PIL.Image.Image, (torch.Tensor, int, tuple, type(None)))
 
-    CONFIGS = datasets_utils.combinations_grid(
+    ADDITIONAL_CONFIGS = datasets_utils.combinations_grid(
         split=("train", "valid", "test", "all"),
         target_type=("attr", "identity", "bbox", "landmarks", ["attr", "identity"]),
     )
@@ -740,7 +742,7 @@ class VOCSegmentationTestCase(datasets_utils.ImageDatasetTestCase):
     DATASET_CLASS = datasets.VOCSegmentation
     FEATURE_TYPES = (PIL.Image.Image, PIL.Image.Image)
 
-    CONFIGS = (
+    ADDITIONAL_CONFIGS = (
         *datasets_utils.combinations_grid(
             year=[f"20{year:02d}" for year in range(7, 13)], image_set=("train", "val", "trainval")
         ),
@@ -929,7 +931,7 @@ class CocoCaptionsTestCase(CocoDetectionTestCase):
 class UCF101TestCase(datasets_utils.VideoDatasetTestCase):
     DATASET_CLASS = datasets.UCF101
 
-    CONFIGS = datasets_utils.combinations_grid(fold=(1, 2, 3), train=(True, False))
+    ADDITIONAL_CONFIGS = datasets_utils.combinations_grid(fold=(1, 2, 3), train=(True, False))
 
     _VIDEO_FOLDER = "videos"
     _ANNOTATIONS_FOLDER = "annotations"
@@ -990,7 +992,7 @@ class LSUNTestCase(datasets_utils.ImageDatasetTestCase):
     DATASET_CLASS = datasets.LSUN
 
     REQUIRED_PACKAGES = ("lmdb",)
-    CONFIGS = datasets_utils.combinations_grid(
+    ADDITIONAL_CONFIGS = datasets_utils.combinations_grid(
         classes=("train", "test", "val", ["bedroom_train", "church_outdoor_train"])
     )
 
@@ -1097,7 +1099,7 @@ class Kinetics400TestCase(datasets_utils.VideoDatasetTestCase):
 class HMDB51TestCase(datasets_utils.VideoDatasetTestCase):
     DATASET_CLASS = datasets.HMDB51
 
-    CONFIGS = datasets_utils.combinations_grid(fold=(1, 2, 3), train=(True, False))
+    ADDITIONAL_CONFIGS = datasets_utils.combinations_grid(fold=(1, 2, 3), train=(True, False))
 
     _VIDEO_FOLDER = "videos"
     _SPLITS_FOLDER = "splits"
@@ -1157,7 +1159,7 @@ class HMDB51TestCase(datasets_utils.VideoDatasetTestCase):
 class OmniglotTestCase(datasets_utils.ImageDatasetTestCase):
     DATASET_CLASS = datasets.Omniglot
 
-    CONFIGS = datasets_utils.combinations_grid(background=(True, False))
+    ADDITIONAL_CONFIGS = datasets_utils.combinations_grid(background=(True, False))
 
     def inject_fake_data(self, tmpdir, config):
         target_folder = (
@@ -1237,7 +1239,7 @@ class SEMEIONTestCase(datasets_utils.ImageDatasetTestCase):
 class USPSTestCase(datasets_utils.ImageDatasetTestCase):
     DATASET_CLASS = datasets.USPS
 
-    CONFIGS = datasets_utils.combinations_grid(train=(True, False))
+    ADDITIONAL_CONFIGS = datasets_utils.combinations_grid(train=(True, False))
 
     def inject_fake_data(self, tmpdir, config):
         num_images = 2 if config["train"] else 1
@@ -1259,7 +1261,7 @@ class SBDatasetTestCase(datasets_utils.ImageDatasetTestCase):
 
     REQUIRED_PACKAGES = ("scipy.io", "scipy.sparse")
 
-    CONFIGS = datasets_utils.combinations_grid(
+    ADDITIONAL_CONFIGS = datasets_utils.combinations_grid(
         image_set=("train", "val", "train_noval"), mode=("boundaries", "segmentation")
     )
 
@@ -1345,7 +1347,7 @@ class PhotoTourTestCase(datasets_utils.ImageDatasetTestCase):
     _TRAIN_FEATURE_TYPES = (torch.Tensor,)
     _TEST_FEATURE_TYPES = (torch.Tensor, torch.Tensor, torch.Tensor)
 
-    CONFIGS = datasets_utils.combinations_grid(train=(True, False))
+    datasets_utils.combinations_grid(train=(True, False))
 
     _NAME = "liberty"