Add request.form data migration support

CHANGELOG.md

@@ -5,6 +5,12 @@ Please follow [the Keep a Changelog standard](https://keepachangelog.com/en/1.0.
 
 ## [Unreleased]
 
+## [6.1.0]
+
+### Added
+
+- Added `form` property to `RequestInfo` for reading and modifying multipart/form-encoded fields (strings and file uploads) inside `convert_request_to_next_version_for` handlers (#359)
+
 ## [6.0.4]
 
 ### Added

cadwyn/structure/data.py

@@ -5,7 +5,7 @@
 from typing import ClassVar, Union, cast
 
 from fastapi import Request, Response
-from starlette.datastructures import MutableHeaders
+from starlette.datastructures import FormData, MutableHeaders, UploadFile
 from typing_extensions import Any, ParamSpec, overload
 
 from cadwyn._utils import same_definition_as_in
@@ -14,9 +14,8 @@
 _P = ParamSpec("_P")
 
 
-# TODO (https://github.com/zmievsa/cadwyn/issues/49): Add form handling
 class RequestInfo:
-    __slots__ = ("_cookies", "_query_params", "_request", "body", "headers")
+    __slots__ = ("_cookies", "_form", "_query_params", "_request", "body", "headers")
 
     def __init__(self, request: Request, body: Any):
         super().__init__()
@@ -25,6 +24,10 @@ def __init__(self, request: Request, body: Any):
         self._cookies = request.cookies
         self._query_params = request.query_params._dict
         self._request = request
+        if isinstance(body, FormData):
+            self._form: Union[list[tuple[str, Union[UploadFile, str]]], None] = list(body.multi_items())
+        else:
+            self._form = None
 
     @property
     def cookies(self) -> dict[str, str]:
@@ -34,6 +37,10 @@ def cookies(self) -> dict[str, str]:
     def query_params(self) -> dict[str, str]:
         return self._query_params
 
+    @property
+    def form(self) -> Union[list[tuple[str, Union[UploadFile, str]]], None]:
+        return self._form
+
 
 # TODO (https://github.com/zmievsa/cadwyn/issues/111): handle _response.media_type and _response.background
 class ResponseInfo:

cadwyn/structure/versions.py

@@ -24,6 +24,7 @@
 from pydantic import BaseModel
 from pydantic_core import PydanticUndefined
 from starlette._utils import is_async_callable
+from starlette.datastructures import FormData
 from typing_extensions import Any, ParamSpec, TypeAlias, TypeVar, assert_never, deprecated, get_args
 
 from cadwyn._internal.context_vars import CURRENT_DEPENDENCY_SOLVER_VAR
@@ -431,12 +432,18 @@ async def _migrate_request(
         del request._headers
         # This gives us the ability to tell the user whether cadwyn is running its dependencies or FastAPI
         CURRENT_DEPENDENCY_SOLVER_VAR.set("cadwyn")
+
+        if request_info._form is not None:
+            body_for_solving = FormData(request_info._form)
+        else:
+            body_for_solving = request_info.body
+
         # Remember this: if len(body_params) == 1, then route.body_schema == route.dependant.body_params[0]
         result = await solve_dependencies(
             request=request,
             response=response,
             dependant=head_dependant,
-            body=request_info.body,
+            body=body_for_solving,
             dependency_overrides_provider=head_route.dependency_overrides_provider,
             async_exit_stack=exit_stack,
             embed_body_fields=embed_body_fields,

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "cadwyn"
-version = "6.0.4"
+version = "6.1.0"
 description = "Production-ready community-driven modern Stripe-like API versioning in FastAPI"
 authors = [{ name = "Stanislav Zmiev", email = "zmievsa@gmail.com" }]
 license = "MIT"

tests/test_data_migrations.py

@@ -9,7 +9,7 @@
 import fastapi
 import pytest
 from dirty_equals import IsPartialDict, IsStr
-from fastapi import APIRouter, Body, Cookie, File, Header, HTTPException, Query, Request, Response, UploadFile
+from fastapi import APIRouter, Body, Cookie, File, Form, Header, HTTPException, Query, Request, Response, UploadFile
 from fastapi.responses import JSONResponse
 from fastapi.routing import APIRoute
 from fastapi.testclient import TestClient
@@ -890,6 +890,188 @@ async def endpoint(file: UploadFile = File(...)):
     }
 
 
+def test__form_migration__can_modify_string_form_field(
+    create_versioned_clients: CreateVersionedClients,
+    test_path: Literal["/test"],
+    router: VersionedAPIRouter,
+):
+    @router.post(test_path)
+    async def endpoint(name: str = Form(...), age: int = Form(...)):
+        return {"name": name, "age": age}
+
+    @convert_request_to_next_version_for(test_path, ["POST"])
+    def migrator(request: RequestInfo):
+        request.form[:] = [(k, "migrated_name") if k == "name" else (k, v) for k, v in request.form]  # type: ignore[index]
+
+    clients = create_versioned_clients(version_change(migrator=migrator))
+    resp_2000 = clients["2000-01-01"].post(test_path, data={"name": "original_name", "age": "25"})
+    resp_2001 = clients["2001-01-01"].post(test_path, data={"name": "original_name", "age": "25"})
+
+    assert resp_2000.json() == {"name": "migrated_name", "age": 25}
+    assert resp_2001.json() == {"name": "original_name", "age": 25}
+
+
+def test__form_migration__form_is_none_for_non_form_requests(
+    create_versioned_clients: CreateVersionedClients,
+    test_path: Literal["/test"],
+    router: VersionedAPIRouter,
+):
+    @router.post(test_path, response_model=AnyResponseSchema)
+    async def endpoint(payload: AnyRequestSchema):
+        return payload
+
+    captured = []
+
+    @convert_request_to_next_version_for(test_path, ["POST"])
+    def migrator(request: RequestInfo):
+        captured.append(request.form)
+
+    clients = create_versioned_clients(version_change(migrator=migrator))
+    clients["2000-01-01"].post(test_path, json={"foo": "bar"})
+
+    assert captured == [None]
+
+
+def test__form_migration__can_add_new_form_field(
+    create_versioned_clients: CreateVersionedClients,
+    test_path: Literal["/test"],
+    router: VersionedAPIRouter,
+):
+    @router.post(test_path)
+    async def endpoint(name: str = Form(...), extra: str = Form("default")):
+        return {"name": name, "extra": extra}
+
+    @convert_request_to_next_version_for(test_path, ["POST"])
+    def migrator(request: RequestInfo):
+        request.form.append(("extra", "added_by_migration"))  # type: ignore[union-attr]
+
+    clients = create_versioned_clients(version_change(migrator=migrator))
+    resp_2000 = clients["2000-01-01"].post(test_path, data={"name": "my_name"})
+    resp_2001 = clients["2001-01-01"].post(test_path, data={"name": "my_name"})
+
+    assert resp_2000.json() == {"name": "my_name", "extra": "added_by_migration"}
+    assert resp_2001.json() == {"name": "my_name", "extra": "default"}
+
+
+def test__form_migration__multi_value_fields_are_preserved(
+    create_versioned_clients: CreateVersionedClients,
+    test_path: Literal["/test"],
+    router: VersionedAPIRouter,
+):
+    @router.post(test_path)
+    async def endpoint(tags: list[str] = Form(...)):
+        return {"tags": tags}
+
+    clients = create_versioned_clients(version_change())
+    resp_2000 = clients["2000-01-01"].post(
+        test_path,
+        content=b"tags=python&tags=web",
+        headers={"content-type": "application/x-www-form-urlencoded"},
+    )
+    resp_2001 = clients["2001-01-01"].post(
+        test_path,
+        content=b"tags=python&tags=web",
+        headers={"content-type": "application/x-www-form-urlencoded"},
+    )
+
+    assert resp_2000.json() == {"tags": ["python", "web"]}
+    assert resp_2001.json() == {"tags": ["python", "web"]}
+
+
+def test__request_body_parsing__empty_body_with_optional_params(
+    create_versioned_clients: CreateVersionedClients,
+    test_path: Literal["/test"],
+    router: VersionedAPIRouter,
+):
+    @router.post(test_path)
+    async def endpoint(name: Optional[str] = Body(default=None), age: Optional[int] = Body(default=None)):
+        return {"name": name, "age": age}
+
+    clients = create_versioned_clients(version_change())
+    resp = clients["2000-01-01"].post(
+        test_path,
+        content=b"",
+        headers={"content-type": "application/json"},
+    )
+
+    assert resp.status_code == 200
+    assert resp.json() == {"name": None, "age": None}
+
+
+def test__request_body_parsing__json_body_without_content_type(
+    create_versioned_clients: CreateVersionedClients,
+    test_path: Literal["/test"],
+    router: VersionedAPIRouter,
+):
+    @router.post(test_path)
+    async def endpoint(name: Optional[str] = Body(default=None), age: Optional[int] = Body(default=None)):
+        return {"name": name, "age": age}
+
+    clients = create_versioned_clients(version_change())
+    resp = clients["2000-01-01"].post(test_path, content=b'{"name": "test", "age": 25}')
+
+    assert resp.status_code == 200
+    assert resp.json() == {"name": "test", "age": 25}
+
+
+def test__request_body_parsing__non_application_content_type(
+    create_versioned_clients: CreateVersionedClients,
+    test_path: Literal["/test"],
+    router: VersionedAPIRouter,
+):
+    @router.post(test_path)
+    async def endpoint(name: Optional[str] = Body(default=None), age: Optional[int] = Body(default=None)):
+        return {"name": name, "age": age}
+
+    clients = create_versioned_clients(version_change())
+    resp = clients["2000-01-01"].post(
+        test_path,
+        content=b'{"name": "test", "age": 25}',
+        headers={"content-type": "text/plain"},
+    )
+
+    assert resp.status_code in [200, 422]
+
+
+def test__request_body_parsing__application_xml_body(
+    create_versioned_clients: CreateVersionedClients,
+    test_path: Literal["/test"],
+    router: VersionedAPIRouter,
+):
+    @router.post(test_path)
+    async def endpoint(name: Optional[str] = Body(default=None), age: Optional[int] = Body(default=None)):
+        return {"name": name, "age": age}
+
+    clients = create_versioned_clients(version_change())
+    resp = clients["2000-01-01"].post(
+        test_path,
+        content=b"<root/>",
+        headers={"content-type": "application/xml"},
+    )
+
+    assert resp.status_code in [200, 422]
+
+
+def test__request_body_parsing__malformed_json_returns_422(
+    create_versioned_clients: CreateVersionedClients,
+    test_path: Literal["/test"],
+    router: VersionedAPIRouter,
+):
+    @router.post(test_path)
+    async def endpoint(name: Optional[str] = Body(default=None), age: Optional[int] = Body(default=None)):
+        return {"name": name, "age": age}
+
+    clients = create_versioned_clients(version_change())
+    resp = clients["2000-01-01"].post(
+        test_path,
+        content=b"not valid json",
+        headers={"content-type": "application/json"},
+    )
+
+    assert resp.status_code == 422
+    assert resp.json()["detail"][0]["type"] == "json_invalid"
+
+
 def test__request_and_response_migrations__for_paths_with_variables__can_match(
     create_versioned_clients: CreateVersionedClients,
     router: VersionedAPIRouter,