query string accept multiple values for same parameter key (#11)

README.rst

@@ -54,7 +54,7 @@ Example:
             return web.json_response({'name': article.name,
                                       'number_of_page': article.nb_page})
 
-        async def get(self, with_comments: Optional[bool]):
+        async def get(self, with_comments: bool=False):
             return web.json_response({'with_comments': with_comments})
 
 
@@ -101,7 +101,7 @@ API:
 Inject Path Parameters
 ~~~~~~~~~~~~~~~~~~~~~~
 
-To declare a path parameters, you must declare your argument as a `positional-only parameters`_:
+To declare a path parameter, you must declare your argument as a `positional-only parameters`_:
 
 
 Example:
@@ -118,18 +118,33 @@ Example:
 Inject Query String Parameters
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-To declare a query parameters, you must declare your argument as a simple argument:
+To declare a query parameter, you must declare your argument as a simple argument:
 
 
 .. code-block:: python3
 
     class AccountView(PydanticView):
-        async def get(self, customer_id: str):
+        async def get(self, customer_id: Optional[str] = None):
             ...
 
     app = web.Application()
     app.router.add_get('/customers', AccountView)
 
+
+A query string parameter is generally optional and we do not want to force the user to set it in the URL.
+It's recommended to define a default value. It's possible to get a multiple value for the same parameter using
+the List type
+
+.. code-block:: python3
+
+    class AccountView(PydanticView):
+        async def get(self, tags: List[str] = []):
+            ...
+
+    app = web.Application()
+    app.router.add_get('/customers', AccountView)
+
+
 Inject Request Body
 ~~~~~~~~~~~~~~~~~~~
 
@@ -152,7 +167,7 @@ To declare a body parameter, you must declare your argument as a simple argument
 Inject HTTP headers
 ~~~~~~~~~~~~~~~~~~~
 
-To declare a HTTP headers parameters, you must declare your argument as a `keyword-only argument`_.
+To declare a HTTP headers parameter, you must declare your argument as a `keyword-only argument`_.
 
 
 .. code-block:: python3

aiohttp_pydantic/injectors.py

@@ -1,10 +1,12 @@
 import abc
+import typing
 from inspect import signature
 from json.decoder import JSONDecodeError
 from typing import Callable, Tuple
 
 from aiohttp.web_exceptions import HTTPBadRequest
 from aiohttp.web_request import BaseRequest
+from multidict import MultiDict
 from pydantic import BaseModel
 
 from .utils import is_pydantic_base_model
@@ -94,9 +96,27 @@ class QueryGetter(AbstractInjector):
         attrs = {"__annotations__": args_spec}
         attrs.update(default_values)
         self.model = type("QueryModel", (BaseModel,), attrs)
+        self.args_spec = args_spec
+        self._is_multiple = frozenset(
+            name for name, spec in args_spec.items() if typing.get_origin(spec) is list
+        )
 
     def inject(self, request: BaseRequest, args_view: list, kwargs_view: dict):
-        kwargs_view.update(self.model(**request.query).dict())
+        kwargs_view.update(self.model(**self._query_to_dict(request.query)).dict())
+
+    def _query_to_dict(self, query: MultiDict):
+        """
+        Return a dict with list as value from the MultiDict.
+
+        The value will be wrapped in a list if the args spec is define as a list or if
+        the multiple values are sent (i.e ?foo=1&foo=2)
+        """
+        return {
+            key: values
+            if len(values := query.getall(key)) > 1 or key in self._is_multiple
+            else value
+            for key, value in query.items()
+        }
 
 
 class HeadersGetter(AbstractInjector):

tests/test_oas/test_view.py

@@ -59,7 +59,7 @@ class PetItemView(PydanticView):
         return web.json_response()
 
 
-class TestResponseReturnASimpleType(PydanticView):
+class ViewResponseReturnASimpleType(PydanticView):
     async def get(self) -> r200[int]:
         """
         Status Codes:
@@ -73,7 +73,7 @@ async def generated_oas(aiohttp_client, loop) -> web.Application:
     app = web.Application()
     app.router.add_view("/pets", PetCollectionView)
     app.router.add_view("/pets/{id}", PetItemView)
-    app.router.add_view("/simple-type", TestResponseReturnASimpleType)
+    app.router.add_view("/simple-type", ViewResponseReturnASimpleType)
     oas.setup(app)
 
     client = await aiohttp_client(app)

tests/test_validation_query_string.py

@@ -1,4 +1,4 @@
-from typing import Optional
+from typing import Optional, List
 
 from aiohttp import web
 
@@ -7,10 +7,19 @@ from aiohttp_pydantic import PydanticView
 
 class ArticleView(PydanticView):
     async def get(
-        self, with_comments: bool, age: Optional[int] = None, nb_items: int = 7
+        self,
+        with_comments: bool,
+        age: Optional[int] = None,
+        nb_items: int = 7,
+        tags: List[str] = [],
     ):
         return web.json_response(
-            {"with_comments": with_comments, "age": age, "nb_items": nb_items}
+            {
+                "with_comments": with_comments,
+                "age": age,
+                "nb_items": nb_items,
+                "tags": tags,
+            }
         )
 
 
@@ -65,7 +74,12 @@ async def test_get_article_with_valid_qs_should_return_the_parsed_type(
     resp = await client.get("/article", params={"with_comments": "yes", "age": 3})
     assert resp.status == 200
     assert resp.content_type == "application/json"
-    assert await resp.json() == {"with_comments": True, "age": 3, "nb_items": 7}
+    assert await resp.json() == {
+        "with_comments": True,
+        "age": 3,
+        "nb_items": 7,
+        "tags": [],
+    }
 
 
 async def test_get_article_with_valid_qs_and_omitted_optional_should_return_default_value(
@@ -77,6 +91,70 @@ async def test_get_article_with_valid_qs_and_omitted_optional_should_return_defa
     client = await aiohttp_client(app)
 
     resp = await client.get("/article", params={"with_comments": "yes"})
-    assert await resp.json() == {"with_comments": True, "age": None, "nb_items": 7}
+    assert await resp.json() == {
+        "with_comments": True,
+        "age": None,
+        "nb_items": 7,
+        "tags": [],
+    }
+    assert resp.status == 200
+    assert resp.content_type == "application/json"
+
+
+async def test_get_article_with_multiple_value_for_qs_age_must_failed(
+    aiohttp_client, loop
+):
+    app = web.Application()
+    app.router.add_view("/article", ArticleView)
+
+    client = await aiohttp_client(app)
+
+    resp = await client.get("/article", params={"age": ["2", "3"], "with_comments": 1})
+    assert await resp.json() == [
+        {
+            "in": "query string",
+            "loc": ["age"],
+            "msg": "value is not a valid integer",
+            "type": "type_error.integer",
+        }
+    ]
+    assert resp.status == 400
+    assert resp.content_type == "application/json"
+
+
+async def test_get_article_with_multiple_value_of_tags(aiohttp_client, loop):
+    app = web.Application()
+    app.router.add_view("/article", ArticleView)
+
+    client = await aiohttp_client(app)
+
+    resp = await client.get(
+        "/article", params={"age": 2, "with_comments": 1, "tags": ["aa", "bb"]}
+    )
+    assert await resp.json() == {
+        "age": 2,
+        "nb_items": 7,
+        "tags": ["aa", "bb"],
+        "with_comments": True,
+    }
+    assert resp.status == 200
+    assert resp.content_type == "application/json"
+
+
+async def test_get_article_with_one_value_of_tags_must_be_a_list(aiohttp_client, loop):
+    app = web.Application()
+    app.router.add_view("/article", ArticleView)
+
+    client = await aiohttp_client(app)
+
+    resp = await client.get(
+        "/article", params={"age": 2, "with_comments": 1, "tags": ["aa"]}
+    )
+    assert await resp.json() == {
+        "age": 2,
+        "nb_items": 7,
+        "tags": ["aa"],
+        "with_comments": True,
+    }
     assert resp.status == 200
     assert resp.content_type == "application/json"