Fix GitHub Actions Worklows and refactor tests (#27)

* Refactor conftest

* Fix docstrings

.github/workflows/frontend.yaml

@@ -10,13 +10,18 @@ on:
     workflows:
     - "Scraping the repositories from Source Graph"
     - "Python App Quality and Testing"
-    branches: [main]
+    branches: [master]
     types:
       - completed
   # Allows you to run this workflow manually from the Actions tab
   # https://docs.github.com/en/actions/using-workflows/manually-running-a-workflow
   # https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#workflow_dispatch
   workflow_dispatch:
+  # Allows to run this workflow on push events to the master branch
+  # https://docs.github.com/en/actions/using-workflows/triggering-a-workflow#using-activity-types-and-filters-with-multiple-events
+  push:
+    branches: [master]
+  page_build:
 
 # Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
 permissions:

app/conftest.py

@@ -7,8 +7,13 @@ from typing import Literal
 import pytest
 import stamina
 from dirty_equals import IsList
-from pytest_mock import MockerFixture
+from sqlalchemy.ext.asyncio import (
-from sqlalchemy.ext.asyncio import AsyncConnection, AsyncSession
+    AsyncConnection,
+    AsyncEngine,
+    AsyncSession,
+    async_sessionmaker,
+    create_async_engine,
+)
 
 from app.database import Dependency, Repo
 from app.factories import DependencyCreateDataFactory
@@ -28,10 +33,38 @@ def _deactivate_retries() -> None:
     stamina.set_active(False)
 
 
-@pytest.fixture(autouse=True)
+@pytest.fixture(scope="session")
-def _test_db(mocker: MockerFixture) -> None:
+def db_path() -> str:
     """Use the in-memory database for tests."""
-    mocker.patch("app.database.DB_PATH", "")
+    return ""  # ":memory:"
+
+
+@pytest.fixture(scope="session")
+def db_connection_string(
+    db_path: str,
+) -> str:
+    """Provide the connection string for the in-memory database."""
+    return f"sqlite+aiosqlite:///{db_path}"
+
+
+@pytest.fixture(scope="session", params=[{"echo": False}], ids=["echo=False"])
+async def db_engine(
+    db_connection_string: str,
+    request: pytest.FixtureRequest,
+) -> AsyncGenerator[AsyncEngine, None, None]:
+    """Create the database engine."""
+    # echo=True enables logging of all SQL statements
+    # https://docs.sqlalchemy.org/en/20/core/engines.html#sqlalchemy.create_engine.params.echo
+    engine = create_async_engine(
+        db_connection_string,
+        **request.param,  # type: ignore
+    )
+    try:
+        yield engine
+    finally:
+        # for AsyncEngine created in function scope, close and
+        # clean-up pooled connections
+        await engine.dispose()
 
 
 @pytest.fixture(scope="session")
@@ -49,35 +82,68 @@ def event_loop(
 
 
 @pytest.fixture(scope="session")
-async def test_db_connection() -> AsyncGenerator[AsyncConnection, None]:
+async def _database_objects(
-    """Use the in-memory database for tests."""
+    db_engine: AsyncEngine,
-    from app.database import Base, engine
+) -> AsyncGenerator[None, None]:
+    """Create the database objects (tables, etc.)."""
+    from app.database import Base
 
+    # Enters a transaction
+    # https://docs.sqlalchemy.org/en/20/orm/extensions/asyncio.html#sqlalchemy.ext.asyncio.AsyncConnection.begin
     try:
-        async with engine.begin() as conn:
+        async with db_engine.begin() as conn:
             await conn.run_sync(Base.metadata.drop_all)
             await conn.run_sync(Base.metadata.create_all)
-            yield conn
+        yield
     finally:
-        # for AsyncEngine created in function scope, close and
+        # Clean up after the testing session is over
-        # clean-up pooled connections
+        async with db_engine.begin() as conn:
-        await engine.dispose()
+            await conn.run_sync(Base.metadata.drop_all)
+
+
+@pytest.fixture(scope="session")
+async def db_connection(
+    db_engine: AsyncEngine,
+) -> AsyncGenerator[AsyncConnection, None]:
+    """Create a database connection."""
+    # Return connection with no transaction
+    # https://docs.sqlalchemy.org/en/20/orm/extensions/asyncio.html#sqlalchemy.ext.asyncio.AsyncEngine.connect
+    async with db_engine.connect() as conn:
+        yield conn
 
 
 @pytest.fixture()
-async def test_db_session(
+async def db_session(
-    test_db_connection: AsyncConnection,
+    db_engine: AsyncEngine,
+    _database_objects: None,
 ) -> AsyncGenerator[AsyncSession, None]:
-    """Use the in-memory database for tests."""
+    """Create a database session."""
-    from app.uow import async_session_uow
+    # The `async_sessionmaker` function is used to create a Session factory
-
+    # https://docs.sqlalchemy.org/en/20/orm/extensions/asyncio.html#sqlalchemy.ext.asyncio.async_sessionmaker
-    async with async_session_uow() as session:
+    async_session_factory = async_sessionmaker(
+        db_engine, expire_on_commit=False, autoflush=False, autocommit=False
+    )
+    async with async_session_factory() as session:
         yield session
 
 
+@pytest.fixture()
+async def db_uow(
+    db_session: AsyncSession,
+) -> AsyncGenerator[AsyncSession, None]:
+    """Provide a transactional scope around a series of operations."""
+    # This context manager will start a transaction, and roll it back at the end
+    # https://docs.sqlalchemy.org/en/20/orm/extensions/asyncio.html#sqlalchemy.ext.asyncio.AsyncSessionTransaction
+    async with db_session.begin() as transaction:
+        try:
+            yield db_session
+        finally:
+            await transaction.rollback()
+
+
 @pytest.fixture()
 async def some_repos(
-    test_db_session: AsyncSession,
+    db_session: AsyncSession,
     source_graph_repo_data_factory: SourceGraphRepoDataFactory,
     dependency_create_data_factory: DependencyCreateDataFactory,
 ) -> list[Repo]:
@@ -99,7 +165,6 @@ async def some_repos(
         )
         for source_graph_repo_data in source_graph_repos_data
     ]
-    test_db_session.add_all(repos)
+    db_session.add_all(repos)
-    await test_db_session.flush()
+    await db_session.flush()
-    await asyncio.gather(*[test_db_session.refresh(repo) for repo in repos])
     return repos

app/database.py

@@ -15,7 +15,6 @@ The module defines the following models:
 
 The database is accessed asynchronously using SQLAlchemy's async API.
 """
-from collections.abc import AsyncGenerator
 from pathlib import PurePath
 from typing import Final
 
@@ -34,11 +33,13 @@ from sqlalchemy.orm import (
     relationship,
 )
 
-DB_PATH: Final[PurePath] = PurePath(__file__).parent.parent / "db.sqlite3"
+from app.types import RevisionHash, SourceGraphRepoId
 
-SQLALCHEMY_DATABASE_URL: Final[str] = f"sqlite+aiosqlite:///{DB_PATH}"
+_DB_PATH: Final[PurePath] = PurePath(__file__).parent.parent / "db.sqlite3"
 
-engine: Final[AsyncEngine] = create_async_engine(SQLALCHEMY_DATABASE_URL)
+_SQLALCHEMY_DATABASE_URL: Final[str] = f"sqlite+aiosqlite:///{_DB_PATH}"
+
+engine: Final[AsyncEngine] = create_async_engine(_SQLALCHEMY_DATABASE_URL)
 
 async_session_maker: Final[async_sessionmaker[AsyncSession]] = async_sessionmaker(
     engine, expire_on_commit=False, autoflush=False, autocommit=False
@@ -55,12 +56,6 @@ metadata = MetaData(
 )
 
 
-async def get_async_session() -> AsyncGenerator[AsyncSession, None]:
-    """Get an async session."""
-    async with async_session_maker() as session:
-        yield session
-
-
 Base = declarative_base(metadata=metadata, cls=AsyncAttrs)
 
 
@@ -72,13 +67,13 @@ class Repo(Base):
     url: Mapped[str] = mapped_column(nullable=False, unique=True)
     description: Mapped[str] = mapped_column(Text, nullable=False)
     stars: Mapped[int] = mapped_column(BigInteger, nullable=False)
-    source_graph_repo_id: Mapped[int | None] = mapped_column(
+    source_graph_repo_id: Mapped[SourceGraphRepoId | None] = mapped_column(
         BigInteger, nullable=True, unique=True
     )
     dependencies: Mapped[list["Dependency"]] = relationship(
         "Dependency", secondary="repo_dependency", back_populates="repos"
     )
-    last_checked_revision: Mapped[str | None] = mapped_column(
+    last_checked_revision: Mapped[RevisionHash | None] = mapped_column(
         String(255), nullable=True
     )
     __table_args__ = (UniqueConstraint("url", "source_graph_repo_id"),)

app/models.py

@@ -2,7 +2,7 @@
 
 from pydantic import BaseModel, ConfigDict, NonNegativeInt
 
-from app.types import DependencyId, RepoId, RevisionHash
+from app.types import DependencyId, RepoId, RevisionHash, SourceGraphRepoId
 
 
 class DependencyCreateData(BaseModel):
@@ -33,6 +33,6 @@ class RepoDetail(BaseModel):
     url: str
     description: str
     stars: NonNegativeInt
-    source_graph_repo_id: int
+    source_graph_repo_id: SourceGraphRepoId | None
     dependencies: list[DependencyDetail]
     last_checked_revision: RevisionHash | None

app/source_graph/client.py

@@ -72,7 +72,7 @@ class AsyncSourceGraphSSEClient:
             headers["Last-Event-ID"] = self._last_event_id
         async with aconnect_sse(
             client=self._aclient,
-            url=str(SOURCE_GRAPH_STREAM_API_URL),
+            url=SOURCE_GRAPH_STREAM_API_URL,
             method="GET",
             headers=headers,
             **kwargs,

app/source_graph/factories.py

@@ -7,6 +7,6 @@ from app.source_graph.models import SourceGraphRepoData
 
 @register_fixture
 class SourceGraphRepoDataFactory(ModelFactory[SourceGraphRepoData]):
-    """Factory for creating RepoCreateData."""
+    """Factory for creating SourceGraphRepoData."""
 
     __model__ = SourceGraphRepoData

app/source_graph/models.py

@@ -1,6 +1,6 @@
 """The models for the Source Graph data."""
 import datetime
-from typing import Literal, NewType, Self
+from typing import Literal, Self
 
 from pydantic import (
     BaseModel,
@@ -11,8 +11,7 @@ from pydantic import (
     computed_field,
 )
 
-#: The ID of a repository from the SourceGraph API.
+from app.types import SourceGraphRepoId
-SourceGraphRepoId = NewType("SourceGraphRepoId", int)
 
 
 class SourceGraphRepoData(BaseModel):

app/source_graph/tests/test_mapper.py

@@ -14,7 +14,7 @@ pytestmark = pytest.mark.anyio
 
 
 async def test_create_or_update_repos_from_source_graph_repos_data(
-    test_db_session: AsyncSession,
+    db_session: AsyncSession,
     source_graph_repo_data_factory: SourceGraphRepoDataFactory,
 ) -> None:
     """Test creating repos from source graph repos data."""
@@ -22,7 +22,7 @@ async def test_create_or_update_repos_from_source_graph_repos_data(
         SourceGraphRepoData
     ] = source_graph_repo_data_factory.batch(5)
     repos = await create_or_update_repos_from_source_graph_repos_data(
-        test_db_session, source_graph_repo_data
+        db_session, source_graph_repo_data
     )
     assert repos == IsList(length=5)
     assert all(repo == IsInstance[database.Repo] for repo in repos)
@@ -31,12 +31,12 @@ async def test_create_or_update_repos_from_source_graph_repos_data(
 
 async def test_create_or_update_repos_from_source_graph_repos_data_update(
     some_repos: list[database.Repo],
-    test_db_session: AsyncSession,
+    db_session: AsyncSession,
     source_graph_repo_data_factory: SourceGraphRepoDataFactory,
 ) -> None:
     """Test updating repos from source graph repos data."""
     assert (
-        await test_db_session.execute(
+        await db_session.execute(
             sqlalchemy.select(sqlalchemy.func.count(database.Repo.id))
         )
     ).scalar() == len(some_repos)
@@ -53,13 +53,13 @@ async def test_create_or_update_repos_from_source_graph_repos_data_update(
         for repo, repo_data in zip(some_repos, source_graph_repos_data, strict=True)
     ]
     repos = await create_or_update_repos_from_source_graph_repos_data(
-        test_db_session, source_graph_repos_data
+        db_session, source_graph_repos_data
     )
     assert repos == IsList(length=len(some_repos))
     assert all(repo == IsInstance[database.Repo] for repo in repos)
     assert all(repo.id is not None for repo in repos)
     assert (
-        await test_db_session.execute(
+        await db_session.execute(
             sqlalchemy.select(sqlalchemy.func.count(database.Repo.id))
         )
     ).scalar() == len(some_repos)

app/tests/test_database.py

@@ -27,7 +27,7 @@ def _assert_repo_properties(
 
 
 async def test_create_repo_no_dependencies(
-    test_db_session: AsyncSession,
+    db_session: AsyncSession,
     source_graph_repo_data_factory: SourceGraphRepoDataFactory,
 ) -> None:
     """Test creating a repo."""
@@ -38,15 +38,15 @@ async def test_create_repo_no_dependencies(
         stars=source_graph_repo_data.stars,
         source_graph_repo_id=source_graph_repo_data.repo_id,
     )
-    test_db_session.add(repo)
+    db_session.add(repo)
-    await test_db_session.flush()
+    await db_session.flush()
-    await test_db_session.refresh(repo)
+    await db_session.refresh(repo)
     _assert_repo_properties(repo, source_graph_repo_data)
     assert (await repo.awaitable_attrs.dependencies) == IsList(length=0)
 
 
 async def test_create_repo_with_dependencies(
-    test_db_session: AsyncSession,
+    db_session: AsyncSession,
     source_graph_repo_data_factory: SourceGraphRepoDataFactory,
     dependency_create_data_factory: DependencyCreateDataFactory,
 ) -> None:
@@ -65,9 +65,8 @@ async def test_create_repo_with_dependencies(
             for dependency_create_data in dependencies_create_data
         ],
     )
-    test_db_session.add(repo)
+    db_session.add(repo)
-    await test_db_session.flush()
+    await db_session.flush()
-    await test_db_session.refresh(repo)
     _assert_repo_properties(repo, source_graph_repo_data)
     repo_dependencies = await repo.awaitable_attrs.dependencies
     assert repo_dependencies == IsList(length=5)
@@ -80,11 +79,11 @@ async def test_create_repo_with_dependencies(
 
 
 async def test_list_repositories(
-    test_db_session: AsyncSession,
+    db_session: AsyncSession,
     some_repos: list[database.Repo],
 ) -> None:
     """Test listing repositories."""
-    repos_from_db_result = await test_db_session.execute(
+    repos_from_db_result = await db_session.execute(
         sa.select(database.Repo).options(
             sqlalchemy.orm.joinedload(database.Repo.dependencies)
         )

app/types.py

@@ -1,6 +1,11 @@
 """Type definitions for the application."""
 from typing import NewType
 
+#: The ID of a repository from the database.
 RepoId = NewType("RepoId", int)
+#: The ID of a repository from the SourceGraph API.
+SourceGraphRepoId = NewType("SourceGraphRepoId", int)
+#: The ID of a dependency from the database.
 DependencyId = NewType("DependencyId", int)
+#: The revision hash of a repository.
 RevisionHash = NewType("RevisionHash", str)

app/uow.py

@@ -20,8 +20,8 @@ async def async_session_uow() -> AsyncGenerator[AsyncSession, None]:
     :return: a UoW instance
     """
     async with async_session_maker() as session:
-        async with session.begin():
+        async with session.begin() as transaction:
             try:
                 yield session
             finally:
-                await session.rollback()
+                await transaction.rollback()