feat(services): add service setup method

Service classes can override the `setup` method to run custom preparation before service execution, such as downloading additional assets or performing consistency checks. Signed-off-by: Claudio Matsuoka <[email protected]>
canonical · Sep 7, 2023 · bd77044 · bd77044
1 parent 6a9f2c6
commit bd77044
Show file tree

Hide file tree

Showing 3 changed files with 18 additions and 0 deletions.
diff --git a/craft_application/services/base.py b/craft_application/services/base.py
@@ -31,3 +31,6 @@ class BaseService(metaclass=abc.ABCMeta):  # noqa: B024
     def __init__(self, app: AppMetadata, project: models.Project) -> None:
         self._app = app
         self._project = project
+
+    def setup(self) -> None:
+        """Application-specific service preparation."""
diff --git a/craft_application/services/service_factory.py b/craft_application/services/service_factory.py
@@ -86,6 +86,7 @@ def __getattr__(self, service: str) -> services.BaseService:
         if issubclass(cls, services.BaseService):
             kwargs = self._service_kwargs.get(service, {})
             instance = cls(self.app, self.project, **kwargs)
+            instance.setup()
             setattr(self, service, instance)
             # Mypy and pyright interpret this differently.
             # Pyright

diff --git a/tests/unit/services/test_service_factory.py b/tests/unit/services/test_service_factory.py
@@ -19,6 +19,7 @@
 import pytest
 import pytest_check
 from craft_application import errors, services
+from craft_cli import emit
 
 
 @pytest.fixture()
@@ -116,3 +117,16 @@ def test_getattr_project_none(app_metadata, fake_package_service_class):
 
     with pytest.raises(errors.ApplicationError):
         _ = factory.package
+
+
+def test_service_setup(app_metadata, fake_project, fake_package_service_class, emitter):
+    class FakePackageService(fake_package_service_class):
+        def setup(self) -> None:
+            emit.debug("setting up package service")
+
+    factory = services.ServiceFactory(
+        app_metadata, project=fake_project, PackageClass=FakePackageService
+    )
+    _ = factory.package
+
+    assert emitter.assert_debug("setting up package service")