✨ Document and test union and list response models (fastapi#108)

docs/src/extra_models/tutorial003.py

@@ -0,0 +1,35 @@
+from typing import Union
+
+from fastapi import FastAPI
+from pydantic import BaseModel
+
+app = FastAPI()
+
+
+class BaseItem(BaseModel):
+    description: str
+    type: str
+
+
+class CarItem(BaseItem):
+    type = "car"
+
+
+class PlaneItem(BaseItem):
+    type = "plane"
+    size: int
+
+
+items = {
+    "item1": {"description": "All my friends drive a low rider", "type": "car"},
+    "item2": {
+        "description": "Music is my aeroplane, it's my aeroplane",
+        "type": "plane",
+        "size": 5,
+    },
+}
+
+
+@app.get("/items/{item_id}", response_model=Union[PlaneItem, CarItem])
+async def read_item(item_id: str):
+    return items[item_id]

docs/src/extra_models/tutorial004.py

@@ -0,0 +1,22 @@
+from typing import List
+
+from fastapi import FastAPI
+from pydantic import BaseModel
+
+app = FastAPI()
+
+
+class Item(BaseModel):
+    name: str
+    description: str
+
+
+items = [
+    {"name": "Foo", "description": "There comes my hero"},
+    {"name": "Red", "description": "It's my aeroplane"},
+]
+
+
+@app.get("/items/", response_model=List[Item])
+async def read_items():
+    return items

docs/tutorial/extra-models.md

@@ -152,6 +152,28 @@ That way, we can declare just the differences between the models (with plaintext
 {!./src/extra_models/tutorial002.py!}
 ```
 
+## `Union` or `anyOf`
+
+You can declare a response to be the `Union` of two types, that means, that the response would be any of the two.
+
+It will be defined in OpenAPI with `anyOf`.
+
+To do that, use the standard Python type hint <a href="https://docs.python.org/3/library/typing.html#typing.Union" target="_blank">`typing.Union`</a>:
+
+```Python hl_lines="1 14 15 18 19 20 33"
+{!./src/extra_models/tutorial003.py!}
+```
+
+## List of models
+
+The same way, you can declare responses of lists of objects.
+
+For that, use the standard Python `typing.List`:
+
+```Python hl_lines="1 20"
+{!./src/extra_models/tutorial004.py!}
+```
+
 ## Recap
 
 Use multiple Pydantic models and inherit freely for each case.

tests/test_tutorial/test_extra_models/test_tutorial003.py

@@ -0,0 +1,125 @@
+from starlette.testclient import TestClient
+
+from extra_models.tutorial003 import app
+
+client = TestClient(app)
+
+openapi_schema = {
+    "openapi": "3.0.2",
+    "info": {"title": "Fast API", "version": "0.1.0"},
+    "paths": {
+        "/items/{item_id}": {
+            "get": {
+                "responses": {
+                    "200": {
+                        "description": "Successful Response",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "title": "Response_Read_Item",
+                                    "anyOf": [
+                                        {"$ref": "#/components/schemas/PlaneItem"},
+                                        {"$ref": "#/components/schemas/CarItem"},
+                                    ],
+                                }
+                            }
+                        },
+                    },
+                    "422": {
+                        "description": "Validation Error",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/HTTPValidationError"
+                                }
+                            }
+                        },
+                    },
+                },
+                "summary": "Read Item Get",
+                "operationId": "read_item_items__item_id__get",
+                "parameters": [
+                    {
+                        "required": True,
+                        "schema": {"title": "Item_Id", "type": "string"},
+                        "name": "item_id",
+                        "in": "path",
+                    }
+                ],
+            }
+        }
+    },
+    "components": {
+        "schemas": {
+            "PlaneItem": {
+                "title": "PlaneItem",
+                "required": ["description", "size"],
+                "type": "object",
+                "properties": {
+                    "description": {"title": "Description", "type": "string"},
+                    "type": {"title": "Type", "type": "string", "default": "plane"},
+                    "size": {"title": "Size", "type": "integer"},
+                },
+            },
+            "CarItem": {
+                "title": "CarItem",
+                "required": ["description"],
+                "type": "object",
+                "properties": {
+                    "description": {"title": "Description", "type": "string"},
+                    "type": {"title": "Type", "type": "string", "default": "car"},
+                },
+            },
+            "ValidationError": {
+                "title": "ValidationError",
+                "required": ["loc", "msg", "type"],
+                "type": "object",
+                "properties": {
+                    "loc": {
+                        "title": "Location",
+                        "type": "array",
+                        "items": {"type": "string"},
+                    },
+                    "msg": {"title": "Message", "type": "string"},
+                    "type": {"title": "Error Type", "type": "string"},
+                },
+            },
+            "HTTPValidationError": {
+                "title": "HTTPValidationError",
+                "type": "object",
+                "properties": {
+                    "detail": {
+                        "title": "Detail",
+                        "type": "array",
+                        "items": {"$ref": "#/components/schemas/ValidationError"},
+                    }
+                },
+            },
+        }
+    },
+}
+
+
+def test_openapi_schema():
+    response = client.get("/openapi.json")
+    assert response.status_code == 200
+    assert response.json() == openapi_schema
+
+
+def test_get_car():
+    response = client.get("/items/item1")
+    assert response.status_code == 200
+    assert response.json() == {
+        "description": "All my friends drive a low rider",
+        "type": "car",
+    }
+
+
+def test_get_plane():
+    response = client.get("/items/item2")
+    assert response.status_code == 200
+    assert response.json() == {
+        "description": "Music is my aeroplane, it's my aeroplane",
+        "type": "plane",
+        "size": 5,
+    }

tests/test_tutorial/test_extra_models/test_tutorial004.py

@@ -0,0 +1,60 @@
+from starlette.testclient import TestClient
+
+from extra_models.tutorial004 import app
+
+client = TestClient(app)
+
+openapi_schema = {
+    "openapi": "3.0.2",
+    "info": {"title": "Fast API", "version": "0.1.0"},
+    "paths": {
+        "/items/": {
+            "get": {
+                "responses": {
+                    "200": {
+                        "description": "Successful Response",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "title": "Response_Read_Items",
+                                    "type": "array",
+                                    "items": {"$ref": "#/components/schemas/Item"},
+                                }
+                            }
+                        },
+                    }
+                },
+                "summary": "Read Items Get",
+                "operationId": "read_items_items__get",
+            }
+        }
+    },
+    "components": {
+        "schemas": {
+            "Item": {
+                "title": "Item",
+                "required": ["name", "description"],
+                "type": "object",
+                "properties": {
+                    "name": {"title": "Name", "type": "string"},
+                    "description": {"title": "Description", "type": "string"},
+                },
+            }
+        }
+    },
+}
+
+
+def test_openapi_schema():
+    response = client.get("/openapi.json")
+    assert response.status_code == 200
+    assert response.json() == openapi_schema
+
+
+def test_get_items():
+    response = client.get("/items/")
+    assert response.status_code == 200
+    assert response.json() == [
+        {"name": "Foo", "description": "There comes my hero"},
+        {"name": "Red", "description": "It's my aeroplane"},
+    ]