Add Open API prefix route - correct docs behind reverse proxy (#26)

Add Open API prefix route - correct docs behind reverse proxy.

tests/test_tutorial/test_sub_applications/test_tutorial001.py

@@ -0,0 +1,66 @@
+from starlette.testclient import TestClient
+
+from sub_applications.tutorial001 import app
+
+client = TestClient(app)
+
+openapi_schema_main = {
+    "openapi": "3.0.2",
+    "info": {"title": "Fast API", "version": "0.1.0"},
+    "paths": {
+        "/app": {
+            "get": {
+                "responses": {
+                    "200": {
+                        "description": "Successful Response",
+                        "content": {"application/json": {"schema": {}}},
+                    }
+                },
+                "summary": "Read Main Get",
+                "operationId": "read_main_app_get",
+            }
+        }
+    },
+}
+openapi_schema_sub = {
+    "openapi": "3.0.2",
+    "info": {"title": "Fast API", "version": "0.1.0"},
+    "paths": {
+        "/subapi/sub": {
+            "get": {
+                "responses": {
+                    "200": {
+                        "description": "Successful Response",
+                        "content": {"application/json": {"schema": {}}},
+                    }
+                },
+                "summary": "Read Sub Get",
+                "operationId": "read_sub_sub_get",
+            }
+        }
+    },
+}
+
+
+def test_openapi_schema_main():
+    response = client.get("/openapi.json")
+    assert response.status_code == 200
+    assert response.json() == openapi_schema_main
+
+
+def test_main():
+    response = client.get("/app")
+    assert response.status_code == 200
+    assert response.json() == {"message": "Hello World from main app"}
+
+
+def test_openapi_schema_sub():
+    response = client.get("/subapi/openapi.json")
+    assert response.status_code == 200
+    assert response.json() == openapi_schema_sub
+
+
+def test_sub():
+    response = client.get("/subapi/sub")
+    assert response.status_code == 200
+    assert response.json() == {"message": "Hello World from sub API"}