Merge pull request #1574 from jceipek/fix-annotated-in-pathex

Fix use of `PathEx` with `Annotated` types

Author: vitalik

ninja/signature/details.py

@@ -1,6 +1,7 @@
 import inspect
 import warnings
 from collections import defaultdict, namedtuple
+from sys import version_info
 from typing import Any, Callable, Dict, Generator, List, Optional, Tuple
 
 import pydantic
@@ -222,9 +223,24 @@ def _get_param_type(self, name: str, arg: inspect.Parameter) -> FuncParam:
 
         if get_origin(annotation) is Annotated:
             args = get_args(annotation)
-            if isinstance(args[1], Param):
+            if isinstance(args[-1], Param):
                 prev_default = default
-                annotation, default = args
+                if len(args) == 2:
+                    annotation, default = args
+                else:
+                    # TODO: Remove version check once support for <=3.8 is dropped.
+                    # Annotated[] is only available at runtime in 3.9+ per
+                    # https://docs.python.org/3/library/typing.html#typing.Annotated
+                    if version_info >= (3, 9):
+                        # NOTE: Annotated[args[:-1]] seems to have the same runtime
+                        # behavior as Annotated[*args[:-1]], but the latter is
+                        # invalid in Python < 3.11 because star expressions
+                        # were not allowed in index expressions.
+                        annotation, default = Annotated[args[:-1]], args[-1]
+                    else:  # pragma: no cover -- requires specific Python versions
+                        raise NotImplementedError(
+                            "This definition requires Python version 3.9+"
+                        )
                 if prev_default != self.signature.empty:
                     default.default = prev_default
 

tests/main.py

@@ -1,9 +1,13 @@
+from sys import version_info
 from typing import List, Optional
 from uuid import UUID
 
+import pydantic
+import pytest
 from django.urls import register_converter
+from typing_extensions import Annotated
 
-from ninja import Field, Path, Query, Router, Schema
+from ninja import Field, P, Path, PathEx, Query, Router, Schema
 
 router = Router()
 
@@ -38,6 +42,46 @@ def get_bool_id(request, item_id: bool):
     return item_id
 
 
+def custom_validator(value: int) -> int:
+    if value != 42:
+        raise ValueError("Input should pass this custom validator")
+    return value
+
+
+CustomValidatedInt = Annotated[
+    int,
+    pydantic.AfterValidator(custom_validator),
+    pydantic.WithJsonSchema({
+        "type": "int",
+        "example": "42",
+    }),
+]
+
+# TODO: Remove this condition once support for <= 3.8 is dropped
+if version_info >= (3, 9):
+
+    @router.get("/path/param_ex/{item_id}")
+    def get_path_param_ex_id(
+        request,
+        item_id: PathEx[CustomValidatedInt, P(description="path_ex description")],
+    ):
+        return item_id
+
+else:
+
+    def test_annotated_path_ex_unsupported():
+        with pytest.raises(NotImplementedError, match="3.9+"):
+
+            @router.get("/path/param_ex/{item_id}")
+            def get_path_param_ex_id(
+                request,
+                item_id: PathEx[
+                    CustomValidatedInt, P(description="path_ex description")
+                ],
+            ):
+                return item_id
+
+
 @router.get("/path/param/{item_id}")
 def get_path_param_id(request, item_id: str = Path(None)):
     return item_id

tests/test_openapi_schema.py

@@ -1,13 +1,26 @@
 import sys
+from sys import version_info
 from typing import Any, List, Union
 from unittest.mock import Mock
 
+import pydantic
 import pytest
 from django.contrib.admin.views.decorators import staff_member_required
 from django.test import Client, override_settings
-from pydantic import ConfigDict
-
-from ninja import Body, Field, File, Form, NinjaAPI, Query, Schema, UploadedFile
+from typing_extensions import Annotated
+
+from ninja import (
+    Body,
+    Field,
+    File,
+    Form,
+    NinjaAPI,
+    P,
+    PathEx,
+    Query,
+    Schema,
+    UploadedFile,
+)
 from ninja.openapi.urls import get_openapi_urls
 from ninja.pagination import PaginationBase, paginate
 from ninja.renderers import JSONRenderer
@@ -28,13 +41,23 @@ class TypeB(Schema):
     b: str
 
 
+AnnotatedStr = Annotated[
+    str,
+    pydantic.WithJsonSchema({
+        "type": "string",
+        "format": "custom-format",
+        "example": "example_string",
+    }),
+]
+
+
 def to_camel(string: str) -> str:
     words = string.split("_")
     return words[0].lower() + "".join(word.capitalize() for word in words[1:])
 
 
 class Response(Schema):
-    model_config = ConfigDict(alias_generator=to_camel, populate_by_name=True)
+    model_config = pydantic.ConfigDict(alias_generator=to_camel, populate_by_name=True)
     i: int
     f: float = Field(..., title="f title", description="f desc")
 
@@ -65,10 +88,42 @@ def method_body_schema(request, data: Payload):
 
 
 @api.get("/test-path/{int:i}/{f}", response=Response)
-def method_path(request, i: int, f: float):
+def method_path(
+    request,
+    i: int,
+    f: float,
+):
     return dict(i=i, f=f)
 
 
+# This definition is only possible in Python 3.9+
+# TODO: Drop this condition once support for <= 3.8 is dropped
+if version_info >= (3, 9):
+
+    @api.get("/test-pathex/{path_ex}", response=AnnotatedStr)
+    def method_pathex(
+        request,
+        path_ex: PathEx[
+            AnnotatedStr,
+            P(description="path_ex description"),
+        ],
+    ):
+        return path_ex
+
+else:
+    with pytest.raises(NotImplementedError, match="3.9+"):
+
+        @api.get("/test-pathex/{path_ex}", response=AnnotatedStr)
+        def method_pathex(
+            request,
+            path_ex: PathEx[
+                AnnotatedStr,
+                P(description="path_ex description"),
+            ],
+        ):
+            return path_ex
+
+
 @api.post("/test-form", response=Response)
 def method_form(request, data: Payload = Form(...)):
     return dict(i=data.i, f=data.f)
@@ -434,6 +489,49 @@ def test_schema_path(schema):
     }
 
 
+@pytest.mark.skipif(
+    version_info < (3, 9),
+    reason="requires py3.9+ for Annotated[] at the route definition site",
+)
+def test_schema_pathex(schema):
+    method_list = schema["paths"]["/api/test-pathex/{path_ex}"]["get"]
+
+    assert "requestBody" not in method_list
+
+    assert method_list["parameters"] == [
+        {
+            "in": "path",
+            "name": "path_ex",
+            "schema": {
+                "title": "Path Ex",
+                "type": "string",
+                "format": "custom-format",
+                "description": "path_ex description",
+                "example": "example_string",
+            },
+            "required": True,
+            "example": "example_string",
+            "description": "path_ex description",
+        },
+    ]
+
+    assert method_list["responses"] == {
+        200: {
+            "content": {
+                "application/json": {
+                    "schema": {
+                        "example": "example_string",
+                        "format": "custom-format",
+                        "title": "Response",
+                        "type": "string",
+                    },
+                },
+            },
+            "description": "OK",
+        }
+    }
+
+
 def test_schema_form(schema):
     method_list = schema["paths"]["/api/test-form"]["post"]
 
@@ -606,7 +704,7 @@ def test_schema_title_description(schema):
                 "schema": {
                     "properties": {
                         "file": {
-                            "description": "file " "param " "desc",
+                            "description": "file param desc",
                             "format": "binary",
                             "title": "File",
                             "type": "string",

tests/test_path.py

@@ -1,3 +1,5 @@
+from sys import version_info
+
 import pytest
 from main import router
 
@@ -33,6 +35,17 @@ def test_text_get():
     ]
 }
 
+response_not_valid_custom = {
+    "detail": [
+        {
+            "ctx": {"error": "Input should pass this custom validator"},
+            "loc": ["path", "item_id"],
+            "msg": "Value error, Input should pass this custom validator",
+            "type": "value_error",
+        }
+    ]
+}
+
 response_not_valid_int_float = {
     "detail": [
         {
@@ -274,6 +287,25 @@ def test_get_path(path, expected_status, expected_response):
     assert response.json() == expected_response
 
 
+@pytest.mark.skipif(
+    version_info < (3, 9),
+    reason="requires py3.9+ for Annotated[] at the route definition site",
+)
+@pytest.mark.parametrize(
+    "path,expected_status,expected_response",
+    [
+        ("/path/param_ex/True", 422, response_not_valid_int),
+        ("/path/param_ex/0", 422, response_not_valid_custom),
+        ("/path/param_ex/42", 200, 42),
+    ],
+)
+def test_get_pathex(path, expected_status, expected_response):
+    response = client.get(path)
+    print(path, response.json())
+    assert response.status_code == expected_status
+    assert response.json() == expected_response
+
+
 @pytest.mark.parametrize(
     "path,expected_status,expected_response",
     [