Add testing

pyproject.toml

@@ -15,3 +15,20 @@ dependencies = [
 [build-system]
 requires = ["uv_build>=0.9.22,<0.10.0"]
 build-backend = "uv_build"
+
+[dependency-groups]
+dev = [
+    "pytest>=9.0.2",
+    "pytest-asyncio>=0.24",
+    "pytest-cov>=7.0.0",
+]
+
+[tool.pytest.ini_options]
+asyncio_mode = "strict"
+addopts = "--cov=adk_firestore_sessionmanager --cov-report=term-missing"
+
+[tool.coverage.run]
+source = ["src/adk_firestore_sessionmanager"]
+
+[tool.coverage.report]
+show_missing = true