added unit tests

Author: 6six7sven

tests/conftest.py

@@ -0,0 +1,37 @@
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+from sqlalchemy.pool import StaticPool
+
+from main import app
+from db.database import Base, get_db
+
+# Use an in-memory SQLite database for testing
+SQLALCHEMY_DATABASE_URL = "sqlite:///:memory:"
+
+engine = create_engine(
+    SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False},
+    poolclass=StaticPool,
+)
+TestingSessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+@pytest.fixture(scope="function")
+def db_session():
+    """Creates a fresh in-memory database for each test."""
+    Base.metadata.create_all(bind=engine)
+    db = TestingSessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()
+        Base.metadata.drop_all(bind=engine)
+
+@pytest.fixture(scope="function")
+def client(db_session):
+    """Returns a FastAPI TestClient that uses the mocked database."""
+    app.dependency_overrides[get_db] = lambda: db_session
+    with TestClient(app) as c:
+        yield c
+    app.dependency_overrides.clear()

tests/test_main.py

@@ -0,0 +1,36 @@
+def test_root(client):
+    """Test the health check endpoint"""
+    response = client.get("/")
+    assert response.status_code == 200
+    assert response.json() == {"message": "FastAPI Image Upload Server"}
+
+def test_register_user(client):
+    """Test successful user registration"""
+    response = client.post(
+        "/register",
+        json={"username": "testuser", "password": "securepassword"}
+    )
+    assert response.status_code == 201
+    assert response.json() == {"message": "User created successfully"}
+
+def test_register_duplicate_user(client):
+    """Test that duplicate usernames are rejected"""
+    client.post("/register", json={"username": "testuser", "password": "securepassword"})
+    
+    response = client.post("/register", json={"username": "testuser", "password": "newpassword"})
+    assert response.status_code == 400
+    assert response.json() == {"detail": "Username already registered"}
+
+def test_login_success(client):
+    """Test login and JWT token generation"""
+    client.post("/register", json={"username": "testuser", "password": "securepassword"})
+    
+    # Note: OAuth2PasswordRequestForm expects form data (data=...), not JSON
+    response = client.post(
+        "/token",
+        data={"username": "testuser", "password": "securepassword"}
+    )
+    assert response.status_code == 200
+    data = response.json()
+    assert "access_token" in data
+    assert data["token_type"] == "bearer"