fix: automated fixes for PR #24

.env.example

@@ -0,0 +1,6 @@
+# Copy this file to .env and fill in real values.
+# Never commit .env to version control.
+POSTGRES_DB=app
+POSTGRES_USER=user
+POSTGRES_PASSWORD=CHANGE_ME
+DATABASE_URL=postgresql://user:CHANGE_ME@db/app

.gitignore

@@ -9,3 +9,9 @@
 
 # macOS
 .DS_Store
+
+# Environment / secrets – never commit real credentials
+.env
+
+# SQLite test database artefact
+*.db

Dockerfile

@@ -3,5 +3,7 @@ RUN apt-get update && apt-get install -y libpq-dev
 COPY . /app
 WORKDIR /app
 RUN pip install -r requirements.txt
+RUN useradd -m appuser
+USER appuser
 EXPOSE 8000
-CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000", "--log-level", "trace"]
+CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000", "--log-level", "info"]

conftest.py

@@ -1,18 +1,34 @@
-import pytest
-from sqlalchemy import create_engine, inspect, text
-from sqlalchemy.orm import sessionmaker
-from fastapi.testclient import TestClient
-from main import create_app
-from dependencies import get_db, database_url
-from models import Base
+import os
+
+# Set a default DATABASE_URL for tests when one is not already provided.
+# This allows the test suite to run without a live PostgreSQL instance
+# by falling back to an in-process SQLite database.
+if not os.getenv("DATABASE_URL"):
+    os.environ["DATABASE_URL"] = "sqlite:///./test.db"
+
+import pytest  # noqa: E402
+from sqlalchemy import create_engine, inspect  # noqa: E402, F401
+from sqlalchemy.orm import sessionmaker  # noqa: E402
+from fastapi.testclient import TestClient  # noqa: E402
+from main import create_app  # noqa: E402
+from dependencies import get_db  # noqa: E402
+from models import Base  # noqa: E402
+
+_DATABASE_URL = os.environ["DATABASE_URL"]
+
 
 @pytest.fixture(scope="session")
 def test_engine():
     """Create test database engine"""
-    test_engine = create_engine(database_url)
-    Base.metadata.create_all(bind=test_engine)
-    yield test_engine
-    Base.metadata.drop_all(bind=test_engine)
+    engine = create_engine(
+        _DATABASE_URL,
+        connect_args={"check_same_thread": False}
+        if _DATABASE_URL.startswith("sqlite")
+        else {},
+    )
+    Base.metadata.create_all(bind=engine)
+    yield engine
+    Base.metadata.drop_all(bind=engine)
 
 
 @pytest.fixture(scope="function")
@@ -37,14 +53,18 @@ def test_app(test_engine):
     """Create test FastAPI application with test database"""
 
     def override_get_db():
-        TestingSessionLocal = sessionmaker(
-            autocommit=False, autoflush=False, bind=test_engine
-        )
-        db = TestingSessionLocal()
+        connection = test_engine.connect()
+        transaction = connection.begin()
+        db = sessionmaker(
+            autocommit=False, autoflush=False, bind=connection,
+            join_transaction_mode="create_savepoint"
+        )()
         try:
             yield db
         finally:
             db.close()
+            transaction.rollback()
+            connection.close()
 
     app = create_app()
     app.dependency_overrides[get_db] = override_get_db

dependencies.py

@@ -1,3 +1,4 @@
+import logging
 from typing import Generator
 import os
 from dotenv import load_dotenv
@@ -6,6 +7,8 @@
 from sqlalchemy.exc import SQLAlchemyError
 from models import Base
 
+logger = logging.getLogger(__name__)
+
 load_dotenv()
 database_url = os.getenv("DATABASE_URL")
 if not database_url:
@@ -23,7 +26,7 @@ def init_db():
     try:
         Base.metadata.create_all(bind=engine)
     except SQLAlchemyError as e:
-        print(f"Error initializing the database: {e}")
+        logger.error("Error initializing the database: %s", e)
         raise
 
 

docker-compose.yml

@@ -24,7 +24,7 @@ services:
       POSTGRES_USER: ${POSTGRES_USER}
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
     ports:
-      - "5432:5432"
+      - "127.0.0.1:5432:5432"
     volumes:
       - postgres_data:/var/lib/postgresql/data
       - ./db.sql:/docker-entrypoint-initdb.d/db.sql

main.py

@@ -1,17 +1,17 @@
-from fastapi import FastAPI, Depends
+from fastapi import FastAPI
 from routers import router
-from dependencies import init_db, get_db
+from dependencies import init_db
 
 
 def create_app() -> FastAPI:
     """Create and configure the FastAPI application"""
-    app = FastAPI()
+    app = FastAPI(docs_url=None, redoc_url=None)
 
     # Initialize database
     init_db()
 
     # Include routers
-    app.include_router(router, prefix="/api", dependencies=[Depends(get_db)])
+    app.include_router(router, prefix="/api")
 
     return app
 

models.py

@@ -1,14 +1,15 @@
+import logging
 from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
 from sqlalchemy import String
 from pydantic import BaseModel, ConfigDict
 
+logger = logging.getLogger(__name__)
+
 
 # SQLAlchemy models
 class Base(DeclarativeBase):
     """Base class for all database models"""
 
-    pass
-
 
 class Book(Base):
     """Book model"""
@@ -18,13 +19,16 @@ class Book(Base):
     id: Mapped[int] = mapped_column(primary_key=True, index=True)
     title: Mapped[str] = mapped_column(String(255), index=True)
     author: Mapped[str] = mapped_column(String(255))
+    isbn: Mapped[str] = mapped_column(String(17))
+
 
 # Pydantic models
 class BookIn(BaseModel):
     """Pydantic model for book input"""
 
     title: str
     author: str
+    isbn: str
 
 
 class BookOut(BaseModel):
@@ -33,5 +37,6 @@ class BookOut(BaseModel):
     id: int
     title: str
     author: str
+    isbn: str
 
     model_config = ConfigDict(from_attributes=True)

repositories.py

@@ -3,38 +3,39 @@
 
 
 # Create a new book
-def create_book(db: Session, book: models.BookIn):
-    db_book = models.Book(title=book.title, author=book.author)
+def create_book(db: Session, book: models.BookIn) -> models.Book:
+    db_book = models.Book(title=book.title, author=book.author, isbn=book.isbn)
     db.add(db_book)
     db.commit()
     db.refresh(db_book)
     return db_book
 
 
 # Get all books
-def get_books(db: Session, skip: int = 0, limit: int = 10):
+def get_books(db: Session, skip: int = 0, limit: int = 10) -> list[models.Book]:
     return db.query(models.Book).offset(skip).limit(limit).all()
 
 
 # Get a book by ID
-def get_book(db: Session, book_id: int):
+def get_book(db: Session, book_id: int) -> models.Book | None:
     return db.query(models.Book).filter(models.Book.id == book_id).first()
 
 
 # Update a book
-def update_book(db: Session, book_id: int, book: models.BookIn):
+def update_book(db: Session, book_id: int, book: models.BookIn) -> models.Book | None:
     db_book = db.query(models.Book).filter(models.Book.id == book_id).first()
     if db_book:
         db_book.title = book.title
         db_book.author = book.author
+        db_book.isbn = book.isbn
         db.commit()
         db.refresh(db_book)
         return db_book
     return None
 
 
 # Delete a book
-def delete_book(db: Session, book_id: int):
+def delete_book(db: Session, book_id: int) -> models.Book | None:
     db_book = db.query(models.Book).filter(models.Book.id == book_id).first()
     if db_book:
         db.delete(db_book)

requirements.txt

@@ -1,7 +1,7 @@
-fastapi[standard]>=0.135.3
-sqlalchemy>=2.0.49
-psycopg2-binary>=2.9.0
-pydantic>=2.12.5
-pytest>=9.0.3
-python-dotenv>=1.2.2
-uvicorn[standard]>=0.44.0
+fastapi[standard]==0.136.1
+sqlalchemy==2.0.49
+psycopg2-binary==2.9.12
+pydantic==2.13.4
+pytest==9.0.3
+python-dotenv==1.2.2
+uvicorn[standard]==0.46.0

routers.py

@@ -1,10 +1,13 @@
+import logging
 from fastapi import APIRouter, Depends, HTTPException, status
 from sqlalchemy.orm import Session
-from typing import List
+from sqlalchemy.exc import IntegrityError
 import models
 import repositories
 from dependencies import get_db
 
+logger = logging.getLogger(__name__)
+
 # Create router with prefix
 router = APIRouter()
 
@@ -15,20 +18,32 @@
 def create_book(book: models.BookIn, db: Session = Depends(get_db)):
     try:
         return repositories.create_book(db=db, book=book)
+    except IntegrityError as e:
+        logger.error("IntegrityError creating book: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="An internal error occurred.",
+        ) from e
     except Exception as e:
-        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(e))
+        logger.error("Unexpected error creating book: %s", e)
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="An internal error occurred.",
+        ) from e
 
 
 @router.get(
-    "/books/", response_model=List[models.BookOut], status_code=status.HTTP_200_OK
+    "/books/", response_model=list[models.BookOut], status_code=status.HTTP_200_OK
 )
 def get_books(skip: int = 0, limit: int = 10, db: Session = Depends(get_db)):
     try:
         return repositories.get_books(db=db, skip=skip, limit=limit)
     except Exception as e:
+        logger.error("Unexpected error retrieving books: %s", e)
         raise HTTPException(
-            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail=str(e)
-        )
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="An internal error occurred.",
+        ) from e
 
 
 @router.get(