✅ Add missing tests for code examples (#14569)

Co-authored-by: Sebastián Ramírez <tiangolo@gmail.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Nils-Hero Lindemann <nilsherolindemann@proton.me>

tests/test_tutorial/test_first_steps/test_tutorial001_tutorial002_tutorial003.py

@@ -1,9 +1,20 @@
+import importlib
+
 import pytest
 from fastapi.testclient import TestClient
 
-from docs_src.first_steps.tutorial001_py39 import app
 
-client = TestClient(app)
+@pytest.fixture(
+    name="client",
+    params=[
+        "tutorial001_py39",
+        "tutorial003_py39",
+    ],
+)
+def get_client(request: pytest.FixtureRequest):
+    mod = importlib.import_module(f"docs_src.first_steps.{request.param}")
+    client = TestClient(mod.app)
+    return client
 
 
 @pytest.mark.parametrize(
@@ -13,13 +24,13 @@ client = TestClient(app)
         ("/nonexistent", 404, {"detail": "Not Found"}),
     ],
 )
-def test_get_path(path, expected_status, expected_response):
+def test_get_path(client: TestClient, path, expected_status, expected_response):
     response = client.get(path)
     assert response.status_code == expected_status
     assert response.json() == expected_response
 
 
-def test_openapi_schema():
+def test_openapi_schema(client: TestClient):
     response = client.get("/openapi.json")
     assert response.status_code == 200
     assert response.json() == {