feat: implement blog project with CI pipeline

tests/unit/test_config.py

@@ -0,0 +1,52 @@
+import os
+from unittest.mock import patch
+
+from app.core.config import Settings
+
+
+class TestSettings:
+    def test_default_values(self) -> None:
+        settings = Settings()
+        assert settings.app_name == "Blog API"
+        assert settings.debug is False
+        assert settings.host == "0.0.0.0"
+        assert settings.port == 8000
+        assert settings.database_url is None
+
+    def test_custom_values(self) -> None:
+        settings = Settings(
+            app_name="Test API",
+            debug=True,
+            host="localhost",
+            port=9000,
+            database_url="postgresql://test",
+        )
+        assert settings.app_name == "Test API"
+        assert settings.debug is True
+        assert settings.host == "localhost"
+        assert settings.port == 9000
+        assert settings.database_url == "postgresql://test"
+
+    def test_settings_from_env(self) -> None:
+        with patch.dict(
+            os.environ,
+            {
+                "APP_NAME": "Env API",
+                "DEBUG": "true",
+                "HOST": "127.0.0.1",
+                "PORT": "8080",
+                "DATABASE_URL": "sqlite:///test.db",
+            },
+        ):
+            settings = Settings()
+            assert settings.app_name == "Env API"
+            assert settings.debug is True
+            assert settings.host == "127.0.0.1"
+            assert settings.port == 8080
+            assert settings.database_url == "sqlite:///test.db"
+
+    def test_global_settings_instance(self) -> None:
+        from app.core.config import settings
+
+        assert isinstance(settings, Settings)
+        assert settings.app_name == "Blog API"