✨ Allow disabling docs UIs by disabling OpenAPI (#1421)

* ✨ Allow disabling docs UIs by disabling openapi_url

* 📝 Add docs for disabling OpenAPI and docs in prod or other environments

* ✅ Add tests for disabling OpenAPI and docs

tests/test_tutorial/test_conditional_openapi/test_tutorial001.py

@@ -0,0 +1,46 @@
+import importlib
+
+from fastapi.testclient import TestClient
+
+from conditional_openapi import tutorial001
+
+openapi_schema = {
+    "openapi": "3.0.2",
+    "info": {"title": "FastAPI", "version": "0.1.0"},
+    "paths": {
+        "/": {
+            "get": {
+                "summary": "Root",
+                "operationId": "root__get",
+                "responses": {
+                    "200": {
+                        "description": "Successful Response",
+                        "content": {"application/json": {"schema": {}}},
+                    }
+                },
+            }
+        }
+    },
+}
+
+
+def test_default_openapi():
+    client = TestClient(tutorial001.app)
+    response = client.get("/openapi.json")
+    assert response.json() == openapi_schema
+    response = client.get("/docs")
+    assert response.status_code == 200, response.text
+    response = client.get("/redoc")
+    assert response.status_code == 200, response.text
+
+
+def test_disable_openapi(monkeypatch):
+    monkeypatch.setenv("OPENAPI_URL", "")
+    importlib.reload(tutorial001)
+    client = TestClient(tutorial001.app)
+    response = client.get("/openapi.json")
+    assert response.status_code == 404, response.text
+    response = client.get("/docs")
+    assert response.status_code == 404, response.text
+    response = client.get("/redoc")
+    assert response.status_code == 404, response.text