Include specs in asset module loaders

examples/docs_snippets/docs_snippets_tests/guides_tests/asset_tutorial_tests/test_cereal.py

@@ -6,5 +6,5 @@
 
 @patch_cereal_requests
 def test_cereal():
-    assets, source_assets, _ = load_assets_from_modules([cereal])
-    assert materialize([*assets, *source_assets])
+    assets = load_assets_from_modules([cereal])
+    assert materialize(assets)

examples/docs_snippets/docs_snippets_tests/guides_tests/asset_tutorial_tests/test_serial_asset_graph.py

@@ -6,5 +6,5 @@
 
 @patch_cereal_requests
 def test_serial_asset_graph():
-    assets, source_assets, _ = load_assets_from_modules([serial_asset_graph])
-    assert materialize([*assets, *source_assets])
+    assets = load_assets_from_modules([serial_asset_graph])
+    assert materialize(assets)

python_modules/dagster-test/dagster_test/toys/repo.py

@@ -1,6 +1,8 @@
 import warnings
+from typing import Sequence, cast
 
 from dagster import ExperimentalWarning
+from dagster._core.definitions.assets import AssetsDefinition
 from dagster._time import get_current_timestamp
 
 # squelch experimental warnings since we often include experimental things in toys for development
@@ -164,19 +166,21 @@ def column_schema_repository():
 def table_metadata_repository():
     from dagster_test.toys import table_metadata
 
-    return load_assets_from_modules([table_metadata])
+    return cast(Sequence[AssetsDefinition], load_assets_from_modules([table_metadata]))
 
 
 @repository
 def long_asset_keys_repository():
     from dagster_test.toys import long_asset_keys
 
-    return load_assets_from_modules([long_asset_keys])
+    return cast(Sequence[AssetsDefinition], load_assets_from_modules([long_asset_keys]))
 
 
-@repository  # pyright: ignore[reportArgumentType]
+@repository
 def big_honkin_assets_repository():
-    return [load_assets_from_modules([big_honkin_asset_graph_module])]
+    return cast(
+        Sequence[AssetsDefinition], [load_assets_from_modules([big_honkin_asset_graph_module])]
+    )
 
 
 @repository
@@ -208,11 +212,11 @@ def assets_with_sensors_repository():
 def conditional_assets_repository():
     from dagster_test.toys import conditional_assets
 
-    return load_assets_from_modules([conditional_assets])
+    return cast(Sequence[AssetsDefinition], load_assets_from_modules([conditional_assets]))
 
 
 @repository
 def data_versions_repository():
     from dagster_test.toys import data_versions
 
-    return load_assets_from_modules([data_versions])
+    return cast(Sequence[AssetsDefinition], load_assets_from_modules([data_versions]))

python_modules/dagster/dagster/_core/code_pointer.py

@@ -190,8 +190,7 @@ def _load_target_from_module(module: ModuleType, fn_name: str, error_suffix: str
     if fn_name == LOAD_ALL_ASSETS:
         # LOAD_ALL_ASSETS is a special symbol that's returned when, instead of loading a particular
         # attribute, we should load all the assets in the module.
-        module_assets, module_source_assets, _ = load_assets_from_modules([module])
-        return [*module_assets, *module_source_assets]
+        return load_assets_from_modules([module])
     else:
         if not hasattr(module, fn_name):
             raise DagsterInvariantViolationError(f"{fn_name} not found {error_suffix}")

python_modules/dagster/dagster/_core/definitions/load_assets_from_modules.py

@@ -63,8 +63,8 @@ def find_subclasses_in_module(
             yield value
 
 
-LoadableAssetTypes = Union[AssetsDefinition, SourceAsset, CacheableAssetsDefinition]
-KeyScopedAssetObjects = (AssetsDefinition, SourceAsset)
+LoadableAssetTypes = Union[AssetsDefinition, AssetSpec, SourceAsset, CacheableAssetsDefinition]
+KeyScopedAssetObjects = (AssetsDefinition, AssetSpec, SourceAsset)
 
 
 class LoadedAssetsList:
@@ -81,7 +81,8 @@ def from_modules(cls, modules: Iterable[ModuleType]) -> "LoadedAssetsList":
             {
                 module.__name__: list(
                     find_objects_in_module_of_types(
-                        module, (AssetsDefinition, SourceAsset, CacheableAssetsDefinition)
+                        module,
+                        (AssetsDefinition, SourceAsset, CacheableAssetsDefinition, AssetSpec),
                     )
                 )
                 for module in modules
@@ -175,7 +176,7 @@ def _inner(spec: AssetSpec) -> AssetSpec:
 
 
 def key_iterator(
-    asset: Union[AssetsDefinition, SourceAsset], included_targeted_keys: bool = False
+    asset: Union[AssetsDefinition, SourceAsset, AssetSpec], included_targeted_keys: bool = False
 ) -> Iterator[AssetKey]:
     return (
         iter(
@@ -203,7 +204,8 @@ def load_assets_from_modules(
     automation_condition: Optional[AutomationCondition] = None,
     backfill_policy: Optional[BackfillPolicy] = None,
     source_key_prefix: Optional[CoercibleToAssetKeyPrefix] = None,
-) -> Sequence[Union[AssetsDefinition, SourceAsset, CacheableAssetsDefinition]]:
+    include_specs: bool = False,
+) -> Sequence[Union[AssetsDefinition, AssetSpec, SourceAsset, CacheableAssetsDefinition]]:
     """Constructs a list of assets and source assets from the given modules.
 
     Args:
@@ -226,6 +228,15 @@ def load_assets_from_modules(
         Sequence[Union[AssetsDefinition, SourceAsset]]:
             A list containing assets and source assets defined in the given modules.
     """
+
+    def _asset_filter(asset: LoadableAssetTypes) -> bool:
+        if isinstance(asset, AssetsDefinition):
+            # We don't load asset checks with asset module loaders.
+            return not has_only_asset_checks(asset)
+        if isinstance(asset, AssetSpec):
+            return include_specs
+        return True
+
     return (
         LoadedAssetsList.from_modules(modules)
         .to_post_load()
@@ -245,7 +256,7 @@ def load_assets_from_modules(
                 backfill_policy, "backfill_policy", BackfillPolicy
             ),
         )
-        .assets_only
+        .get_objects(_asset_filter)
     )
 
 
@@ -258,7 +269,8 @@ def load_assets_from_current_module(
     automation_condition: Optional[AutomationCondition] = None,
     backfill_policy: Optional[BackfillPolicy] = None,
     source_key_prefix: Optional[CoercibleToAssetKeyPrefix] = None,
-) -> Sequence[Union[AssetsDefinition, SourceAsset, CacheableAssetsDefinition]]:
+    include_specs: bool = False,
+) -> Sequence[Union[AssetsDefinition, AssetSpec, SourceAsset, CacheableAssetsDefinition]]:
     """Constructs a list of assets, source assets, and cacheable assets from the module where
     this function is called.
 
@@ -296,6 +308,7 @@ def load_assets_from_current_module(
         ),
         backfill_policy=backfill_policy,
         source_key_prefix=source_key_prefix,
+        include_specs=include_specs,
     )
 
 
@@ -309,6 +322,7 @@ def load_assets_from_package_module(
     automation_condition: Optional[AutomationCondition] = None,
     backfill_policy: Optional[BackfillPolicy] = None,
     source_key_prefix: Optional[CoercibleToAssetKeyPrefix] = None,
+    include_specs: bool = False,
 ) -> Sequence[LoadableAssetTypes]:
     """Constructs a list of assets and source assets that includes all asset
     definitions, source assets, and cacheable assets in all sub-modules of the given package module.
@@ -344,6 +358,7 @@ def load_assets_from_package_module(
         automation_condition=automation_condition,
         backfill_policy=backfill_policy,
         source_key_prefix=source_key_prefix,
+        include_specs=include_specs,
     )
 
 
@@ -356,7 +371,8 @@ def load_assets_from_package_name(
     auto_materialize_policy: Optional[AutoMaterializePolicy] = None,
     backfill_policy: Optional[BackfillPolicy] = None,
     source_key_prefix: Optional[CoercibleToAssetKeyPrefix] = None,
-) -> Sequence[Union[AssetsDefinition, SourceAsset, CacheableAssetsDefinition]]:
+    include_specs: bool = False,
+) -> Sequence[Union[AssetsDefinition, AssetSpec, SourceAsset, CacheableAssetsDefinition]]:
     """Constructs a list of assets, source assets, and cacheable assets that includes all asset
     definitions and source assets in all sub-modules of the given package.
 
@@ -389,6 +405,7 @@ def load_assets_from_package_name(
         auto_materialize_policy=auto_materialize_policy,
         backfill_policy=backfill_policy,
         source_key_prefix=source_key_prefix,
+        include_specs=include_specs,
     )
 
 
@@ -410,11 +427,17 @@ def find_modules_in_package(package_module: ModuleType) -> Iterable[ModuleType]:
 
 
 def replace_keys_in_asset(
-    asset: Union[AssetsDefinition, SourceAsset],
+    asset: Union[AssetsDefinition, AssetSpec, SourceAsset],
     key_replacements: Mapping[AssetKey, AssetKey],
-) -> Union[AssetsDefinition, SourceAsset]:
-    updated_object = (
-        asset.with_attributes(
+) -> Union[AssetsDefinition, AssetSpec, SourceAsset]:
+    if isinstance(asset, SourceAsset):
+        return asset.with_attributes(key=key_replacements.get(asset.key, asset.key))
+    if isinstance(asset, AssetSpec):
+        return asset.replace_attributes(
+            key=key_replacements.get(asset.key, asset.key),
+        )
+    else:
+        updated_object = asset.with_attributes(
             output_asset_key_replacements={
                 key: key_replacements.get(key, key)
                 for key in key_iterator(asset, included_targeted_keys=True)
@@ -423,34 +446,31 @@ def replace_keys_in_asset(
                 key: key_replacements.get(key, key) for key in asset.keys_by_input_name.values()
             },
         )
-        if isinstance(asset, AssetsDefinition)
-        else asset.with_attributes(key=key_replacements.get(asset.key, asset.key))
-    )
-    if isinstance(asset, AssetChecksDefinition):
-        updated_object = cast(AssetsDefinition, updated_object)
-        updated_object = AssetChecksDefinition.create(
-            keys_by_input_name=updated_object.keys_by_input_name,
-            node_def=updated_object.op,
-            check_specs_by_output_name=updated_object.check_specs_by_output_name,
-            resource_defs=updated_object.resource_defs,
-            can_subset=updated_object.can_subset,
-        )
-    return updated_object
+        if isinstance(asset, AssetsDefinition) and has_only_asset_checks(asset):
+            updated_object = AssetChecksDefinition.create(
+                keys_by_input_name=updated_object.keys_by_input_name,
+                node_def=updated_object.op,
+                check_specs_by_output_name=updated_object.check_specs_by_output_name,
+                resource_defs=updated_object.resource_defs,
+                can_subset=updated_object.can_subset,
+            )
+        return updated_object
 
 
 class ResolvedAssetObjectList:
     def __init__(
         self,
-        loaded_objects: Sequence[Union[AssetsDefinition, SourceAsset, CacheableAssetsDefinition]],
+        loaded_objects: Sequence[LoadableAssetTypes],
     ):
         self.loaded_objects = loaded_objects
 
     @cached_property
-    def assets_defs(self) -> Sequence[AssetsDefinition]:
+    def assets_defs_and_specs(self) -> Sequence[Union[AssetsDefinition, AssetSpec]]:
         return [
             dagster_object
             for dagster_object in self.loaded_objects
-            if isinstance(dagster_object, AssetsDefinition) and dagster_object.keys
+            if (isinstance(dagster_object, AssetsDefinition) and dagster_object.keys)
+            or isinstance(dagster_object, AssetSpec)
         ]
 
     @cached_property
@@ -462,8 +482,10 @@ def checks_defs(self) -> Sequence[AssetChecksDefinition]:
         ]
 
     @cached_property
-    def assets_and_checks_defs(self) -> Sequence[Union[AssetsDefinition, AssetChecksDefinition]]:
-        return [*self.assets_defs, *self.checks_defs]
+    def assets_defs_specs_and_checks_defs(
+        self,
+    ) -> Sequence[Union[AssetsDefinition, AssetSpec, AssetChecksDefinition]]:
+        return [*self.assets_defs_and_specs, *self.checks_defs]
 
     @cached_property
     def source_assets(self) -> Sequence[SourceAsset]:
@@ -475,9 +497,10 @@ def cacheable_assets(self) -> Sequence[CacheableAssetsDefinition]:
             asset for asset in self.loaded_objects if isinstance(asset, CacheableAssetsDefinition)
         ]
 
-    @cached_property
-    def assets_only(self) -> Sequence[LoadableAssetTypes]:
-        return [*self.source_assets, *self.assets_defs, *self.cacheable_assets]
+    def get_objects(
+        self, filter_fn: Callable[[LoadableAssetTypes], bool]
+    ) -> Sequence[LoadableAssetTypes]:
+        return [asset for asset in self.loaded_objects if filter_fn(asset)]
 
     def assets_with_loadable_prefix(
         self, key_prefix: CoercibleToAssetKeyPrefix
@@ -489,7 +512,7 @@ def assets_with_loadable_prefix(
         result_list = []
         all_asset_keys = {
             key
-            for asset_object in self.assets_and_checks_defs
+            for asset_object in self.assets_defs_specs_and_checks_defs
             for key in key_iterator(asset_object, included_targeted_keys=True)
         }
         key_replacements = {key: key.with_prefix(key_prefix) for key in all_asset_keys}
@@ -554,6 +577,10 @@ def with_attributes(
                 return_list.append(
                     asset.with_attributes(group_name=group_name if group_name else asset.group_name)
                 )
+            elif isinstance(asset, AssetSpec):
+                return_list.append(
+                    _spec_mapper_disallow_group_override(group_name, automation_condition)(asset)
+                )
             else:
                 return_list.append(
                     asset.with_attributes_for_all(

python_modules/dagster/dagster/_core/definitions/metadata/source_code.py

@@ -16,7 +16,7 @@
 from dagster._serdes import whitelist_for_serdes
 
 if TYPE_CHECKING:
-    from dagster._core.definitions.assets import AssetsDefinition, SourceAsset
+    from dagster._core.definitions.assets import AssetsDefinition, AssetSpec, SourceAsset
     from dagster._core.definitions.cacheable_assets import CacheableAssetsDefinition
 
 DEFAULT_SOURCE_FILE_KEY = "asset_definition"
@@ -86,11 +86,11 @@ def namespace(cls) -> str:
 
 
 def _with_code_source_single_definition(
-    assets_def: Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition"],
-) -> Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition"]:
+    assets_def: Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition", "AssetSpec"],
+) -> Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition", "AssetSpec"]:
     from dagster._core.definitions.assets import AssetsDefinition
 
-    # SourceAsset doesn't have an op definition to point to - cacheable assets
+    # SourceAsset and AssetSpec don't have an op definition to point to - cacheable assets
     # will be supported eventually but are a bit trickier
     if not isinstance(assets_def, AssetsDefinition):
         return assets_def
@@ -242,8 +242,8 @@ def convert_local_path_to_git_path(
 def _convert_local_path_to_git_path_single_definition(
     base_git_url: str,
     file_path_mapping: FilePathMapping,
-    assets_def: Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition"],
-) -> Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition"]:
+    assets_def: Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition", "AssetSpec"],
+) -> Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition", "AssetSpec"]:
     from dagster._core.definitions.assets import AssetsDefinition
 
     # SourceAsset doesn't have an op definition to point to - cacheable assets
@@ -293,11 +293,13 @@ def _build_gitlab_url(url: str, branch: str) -> str:
 
 @experimental
 def link_code_references_to_git(
-    assets_defs: Sequence[Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition"]],
+    assets_defs: Sequence[
+        Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition", "AssetSpec"]
+    ],
     git_url: str,
     git_branch: str,
     file_path_mapping: FilePathMapping,
-) -> Sequence[Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition"]]:
+) -> Sequence[Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition", "AssetSpec"]]:
     """Wrapper function which converts local file path code references to source control URLs
     based on the provided source control URL and branch.
 
@@ -353,8 +355,10 @@ def link_code_references_to_git(
 
 @experimental
 def with_source_code_references(
-    assets_defs: Sequence[Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition"]],
-) -> Sequence[Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition"]]:
+    assets_defs: Sequence[
+        Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition", "AssetSpec"]
+    ],
+) -> Sequence[Union["AssetsDefinition", "SourceAsset", "CacheableAssetsDefinition", "AssetSpec"]]:
     """Wrapper function which attaches local code reference metadata to the provided asset definitions.
     This points to the filepath and line number where the asset body is defined.
 

python_modules/dagster/dagster/_core/workspace/autodiscovery.py

@@ -114,9 +114,9 @@ def loadable_targets_from_loaded_module(module: ModuleType) -> Sequence[Loadable
             )
         )
 
-    module_assets, module_source_assets, _ = load_assets_from_modules([module])
-    if len(module_assets) > 0 or len(module_source_assets) > 0:
-        return [LoadableTarget(LOAD_ALL_ASSETS, [*module_assets, *module_source_assets])]
+    assets = load_assets_from_modules([module])
+    if len(assets) > 0:
+        return [LoadableTarget(LOAD_ALL_ASSETS, assets)]
 
     raise DagsterInvariantViolationError(
         "No Definitions, RepositoryDefinition, Job, Pipeline, Graph, or AssetsDefinition found in "

python_modules/dagster/dagster_tests/asset_defs_tests/asset_package/__init__.py

@@ -1,4 +1,5 @@
 from dagster import AssetKey, SourceAsset, asset
+from dagster._core.definitions.asset_spec import AssetSpec
 
 
 @asset
@@ -29,4 +30,7 @@ def make_list_of_source_assets():
     return [buddy_holly, jerry_lee_lewis]
 
 
+top_level_spec = AssetSpec("top_level_spec")
+
+
 list_of_assets_and_source_assets = [*make_list_of_assets(), *make_list_of_source_assets()]