chore: move Descriptor type alias to oras/types.py

The Descriptor type is now defined alongside container_type in
oras/types.py, the project's established home for cross-cutting
type aliases. oras/copy/descriptor.py re-exports it for backward
compatibility, so existing imports continue to work.

Signed-off-by: jiwangCHEN <hyper1char@gmail.com>

Author: jiwangCHEN

oras/copy/__init__.py

@@ -49,10 +49,10 @@
 )
 from oras.copy.adapters import LayoutTarget, RegistryTarget
 from oras.copy.copy import copy
-from oras.copy.descriptor import Descriptor
 from oras.copy.errors import CopyError, CopyErrorOrigin
 from oras.copy.graph import SkipNode
 from oras.copy.options import CopyGraphOptions, CopyOptions
+from oras.types import Descriptor
 
 __all__ = [
     # Core function

oras/copy/adapters.py

@@ -22,9 +22,10 @@
 
 import oras.defaults
 import oras.utils
-from oras.copy.descriptor import Descriptor, is_manifest
+from oras.copy.descriptor import is_manifest
 from oras.layout.layout import Layout
 from oras.provider import Registry
+from oras.types import Descriptor
 from oras.utils.fileio import read_json
 
 _VALID_DIGEST_RE = re.compile(r"^[a-z0-9]+:[a-f0-9]+$")

oras/copy/content.py

@@ -15,7 +15,7 @@
 import threading
 from typing import BinaryIO, Callable, List, Optional, Protocol, Tuple, runtime_checkable
 
-from oras.copy.descriptor import Descriptor
+from oras.types import Descriptor
 
 
 # ---------------------------------------------------------------------------

oras/copy/copy.py

@@ -17,10 +17,11 @@
 from typing import Optional
 
 from oras.copy import content as content_mod
-from oras.copy.descriptor import Descriptor, descriptors_equal
+from oras.copy.descriptor import descriptors_equal
 from oras.copy.errors import CopyError, CopyErrorOrigin
 from oras.copy.graph import SkipNode, copy_graph
 from oras.copy.options import DEFAULT_MAX_METADATA_BYTES, CopyOptions
+from oras.types import Descriptor
 
 
 def copy(

oras/copy/descriptor.py

@@ -8,10 +8,18 @@
 __author__ = "The ORAS Authors"
 __license__ = "Apache-2.0"
 
-from typing import Any, Dict, Tuple
-
-# Type alias for OCI descriptors (plain dicts in oras-py)
-Descriptor = Dict[str, Any]
+from typing import Tuple
+
+from oras.types import Descriptor
+
+__all__ = [
+    "Descriptor",
+    "is_manifest",
+    "is_foreign_layer",
+    "descriptor_key",
+    "descriptors_equal",
+    "remove_foreign_layers",
+]
 
 # OCI and Docker manifest media types
 _MANIFEST_MEDIA_TYPES = frozenset(

oras/copy/graph.py

@@ -19,11 +19,11 @@
 
 from oras.copy import content as content_mod
 from oras.copy.descriptor import (
-    Descriptor,
     descriptors_equal,
     is_manifest,
     remove_foreign_layers,
 )
+from oras.types import Descriptor
 from oras.copy.errors import CopyError, CopyErrorOrigin
 from oras.copy.options import (
     DEFAULT_CONCURRENCY,

oras/copy/options.py

@@ -11,7 +11,7 @@
 from dataclasses import dataclass, field
 from typing import Callable, List, Optional
 
-from oras.copy.descriptor import Descriptor
+from oras.types import Descriptor
 
 # Default concurrency matches dockerd and containerd (3 concurrent copies)
 DEFAULT_CONCURRENCY: int = 3

oras/copy/tracker.py

@@ -12,7 +12,8 @@
 import threading
 from typing import Tuple
 
-from oras.copy.descriptor import Descriptor, descriptor_key
+from oras.copy.descriptor import descriptor_key
+from oras.types import Descriptor
 
 
 class StatusTracker:

oras/tests/conftest.py

@@ -6,7 +6,7 @@
 
 import pytest
 
-from oras.copy.descriptor import Descriptor
+from oras.types import Descriptor
 
 
 class InMemoryTarget:

oras/types.py

@@ -2,9 +2,12 @@
 __copyright__ = "Copyright The ORAS Authors."
 __license__ = "Apache-2.0"
 
-from typing import Union
+from typing import Any, Dict, Union
 
 import oras.container
 
 # container type can be string or container
 container_type = Union[str, oras.container.Container]
+
+# OCI content descriptor (mediaType + digest + size, plus optional fields)
+Descriptor = Dict[str, Any]