Add action for listing the attachments of a melding (#92)

meldingen_core/actions/attachment.py

@@ -1,3 +1,4 @@
+from collections.abc import Collection
 from typing import AsyncIterator, Generic, TypeVar
 from uuid import uuid4
 
@@ -12,13 +13,14 @@
 from meldingen_core.validators import BaseMediaTypeIntegrityValidator, BaseMediaTypeValidator
 
 A = TypeVar("A", bound=Attachment)
+A_co = TypeVar("A_co", bound=Attachment, covariant=True)
 M = TypeVar("M", bound=Melding)
 M_co = TypeVar("M_co", bound=Melding, covariant=True)
 
 
-class UploadAttachmentAction(Generic[A, M, M_co]):
+class UploadAttachmentAction(Generic[A, A_co, M, M_co]):
     _create_attachment: BaseAttachmentFactory[A, M]
-    _attachment_repository: BaseAttachmentRepository
+    _attachment_repository: BaseAttachmentRepository[A, A_co]
     _filesystem: Filesystem
     _verify_token: TokenVerifier[M, M_co]
     _base_directory: str
@@ -28,7 +30,7 @@ class UploadAttachmentAction(Generic[A, M, M_co]):
     def __init__(
         self,
         attachment_factory: BaseAttachmentFactory[A, M],
-        attachment_repository: BaseAttachmentRepository,
+        attachment_repository: BaseAttachmentRepository[A, A_co],
         filesystem: Filesystem,
         token_verifier: TokenVerifier[M, M_co],
         media_type_validator: BaseMediaTypeValidator,
@@ -69,15 +71,15 @@ async def __call__(
         return attachment
 
 
-class DownloadAttachmentAction(Generic[M, M_co]):
+class DownloadAttachmentAction(Generic[A, A_co, M, M_co]):
     _verify_token: TokenVerifier[M, M_co]
-    _attachment_repository: BaseAttachmentRepository
+    _attachment_repository: BaseAttachmentRepository[A, A_co]
     _filesystem: Filesystem
 
     def __init__(
         self,
         token_verifier: TokenVerifier[M, M_co],
-        attachment_repository: BaseAttachmentRepository,
+        attachment_repository: BaseAttachmentRepository[A, A_co],
         filesystem: Filesystem,
     ):
         self._verify_token = token_verifier
@@ -99,3 +101,19 @@ async def __call__(self, melding_id: int, attachment_id: int, token: str) -> Asy
             return await file.get_iterator()
         except filesystem.NotFoundException as exception:
             raise NotFoundException("File not found") from exception
+
+
+class ListAttachmentsAction(Generic[A, A_co, M, M_co]):
+    _verify_token: TokenVerifier[M, M_co]
+    _attachment_repository: BaseAttachmentRepository[A, A_co]
+
+    def __init__(
+        self, token_verifier: TokenVerifier[M, M_co], attachment_repository: BaseAttachmentRepository[A, A_co]
+    ):
+        self._verify_token = token_verifier
+        self._attachment_repository = attachment_repository
+
+    async def __call__(self, melding_id: int, token: str) -> Collection[A_co]:
+        await self._verify_token(melding_id, token)
+
+        return await self._attachment_repository.find_by_melding(melding_id)

meldingen_core/repositories.py

@@ -59,4 +59,10 @@ class BaseQuestionRepository(BaseRepository[Question, Question], metaclass=ABCMe
 class BaseAnswerRepository(BaseRepository[Answer, Answer], metaclass=ABCMeta): ...
 
 
-class BaseAttachmentRepository(BaseRepository[Attachment, Attachment], metaclass=ABCMeta): ...
+A = TypeVar("A", bound=Attachment)
+A_co = TypeVar("A_co", covariant=True, bound=Attachment)
+
+
+class BaseAttachmentRepository(BaseRepository[A, A_co], metaclass=ABCMeta):
+    @abstractmethod
+    async def find_by_melding(self, melding_id: int) -> Collection[A_co]: ...

tests/test_actions/test_attachment.py

@@ -5,7 +5,7 @@
 from plugfs import filesystem
 from plugfs.filesystem import File, Filesystem
 
-from meldingen_core.actions.attachment import DownloadAttachmentAction, UploadAttachmentAction
+from meldingen_core.actions.attachment import DownloadAttachmentAction, ListAttachmentsAction, UploadAttachmentAction
 from meldingen_core.exceptions import NotFoundException
 from meldingen_core.factories import BaseAttachmentFactory
 from meldingen_core.models import Attachment, Melding
@@ -28,9 +28,9 @@ async def test_can_handle_attachment(self) -> None:
 
         filesystem = Mock(Filesystem)
 
-        attachment_repository = Mock(BaseAttachmentRepository)
+        attachment_repository = Mock(BaseAttachmentRepository[Attachment, Attachment])
 
-        action: UploadAttachmentAction[Attachment, Melding, Melding] = UploadAttachmentAction(
+        action: UploadAttachmentAction[Attachment, Attachment, Melding, Melding] = UploadAttachmentAction(
             Mock(BaseAttachmentFactory),
             attachment_repository,
             filesystem,
@@ -55,7 +55,7 @@ async def test_attachment_not_found(self) -> None:
         attachment_repository = Mock(BaseAttachmentRepository)
         attachment_repository.retrieve.return_value = None
 
-        action: DownloadAttachmentAction[Melding, Melding] = DownloadAttachmentAction(
+        action: DownloadAttachmentAction[Attachment, Attachment, Melding, Melding] = DownloadAttachmentAction(
             AsyncMock(TokenVerifier),
             attachment_repository,
             Mock(Filesystem),
@@ -74,7 +74,7 @@ async def test_attachment_does_not_belong_to_melding(self) -> None:
         attachment_repository = Mock(BaseAttachmentRepository)
         attachment_repository.retrieve.return_value = attachment
 
-        action: DownloadAttachmentAction[Melding, Melding] = DownloadAttachmentAction(
+        action: DownloadAttachmentAction[Attachment, Attachment, Melding, Melding] = DownloadAttachmentAction(
             AsyncMock(TokenVerifier),
             attachment_repository,
             Mock(Filesystem),
@@ -97,7 +97,7 @@ async def test_can_handle_attachment_download(self) -> None:
         attachment_repository = Mock(BaseAttachmentRepository)
         attachment_repository.retrieve.return_value = attachment
 
-        action: DownloadAttachmentAction[Melding, Melding] = DownloadAttachmentAction(
+        action: DownloadAttachmentAction[Attachment, Attachment, Melding, Melding] = DownloadAttachmentAction(
             token_verifier,
             attachment_repository,
             Mock(Filesystem),
@@ -123,7 +123,7 @@ async def test_file_not_found(self) -> None:
         filesystem_mock = Mock(Filesystem)
         filesystem_mock.get_file.return_value = file
 
-        action: DownloadAttachmentAction[Melding, Melding] = DownloadAttachmentAction(
+        action: DownloadAttachmentAction[Attachment, Attachment, Melding, Melding] = DownloadAttachmentAction(
             token_verifier,
             attachment_repository,
             filesystem_mock,
@@ -133,3 +133,23 @@ async def test_file_not_found(self) -> None:
             await action(123, 456, "supersecrettoken")
 
         assert str(exception_info.value) == "File not found"
+
+
+class TestListAttachmentsAction:
+    @pytest.mark.anyio
+    async def test_can_list_attachments(self) -> None:
+        token = "supersecrettoken"
+        melding_id = 123
+        repo_attachments: list[Attachment] = []
+        token_verifier = AsyncMock(TokenVerifier)
+        repository = Mock(BaseAttachmentRepository)
+        repository.find_by_melding.return_value = repo_attachments
+
+        action: ListAttachmentsAction[Attachment, Attachment, Melding, Melding] = ListAttachmentsAction(
+            token_verifier, repository
+        )
+        attachments = await action(melding_id, token)
+
+        assert repo_attachments == attachments
+        token_verifier.assert_awaited_once()
+        repository.find_by_melding.assert_awaited_once_with(melding_id)