From 20661e1301a41c163f1ed585758f2742ee7ff5c2 Mon Sep 17 00:00:00 2001
From: Irfanuddin <irfanudeen08@gmail.com>
Date: Tue, 8 Nov 2022 01:55:39 +0530
Subject: [PATCH] tests: added tests

---
 fastapi/dependencies/utils.py              |   6 +-
 fastapi/routing.py                         |   7 +-
 tests/test_include_duplicate_path_route.py | 121 +++++++++++++++++++++
 3 files changed, 132 insertions(+), 2 deletions(-)
 create mode 100644 tests/test_include_duplicate_path_route.py

diff --git a/fastapi/dependencies/utils.py b/fastapi/dependencies/utils.py
index 64a6c1276..d35aa1b36 100644
--- a/fastapi/dependencies/utils.py
+++ b/fastapi/dependencies/utils.py
@@ -12,6 +12,7 @@ from typing import (
     Mapping,
     Optional,
     Sequence,
+    Set,
     Tuple,
     Type,
     Union,
@@ -74,7 +75,6 @@ sequence_shape_to_type = {
     SHAPE_TUPLE_ELLIPSIS: list,
 }
 
-
 multipart_not_installed_error = (
     'Form data requires "python-multipart" to be installed. \n'
     'You can install "python-multipart" with: \n\n'
@@ -755,3 +755,7 @@ def get_body_field(*, dependant: Dependant, name: str) -> Optional[ModelField]:
     )
     check_file_field(final_field)
     return final_field
+
+
+def get_path_hash_val(path: str, methods: Optional[Set[str]]) -> str:
+    return f"path:{path};methods:{methods}"
diff --git a/fastapi/routing.py b/fastapi/routing.py
index 06c0a7342..a923cd29f 100644
--- a/fastapi/routing.py
+++ b/fastapi/routing.py
@@ -26,6 +26,7 @@ from fastapi.dependencies.utils import (
     get_body_field,
     get_dependant,
     get_parameterless_sub_dependant,
+    get_path_hash_val,
     solve_dependencies,
 )
 from fastapi.encoders import DictIntStrAny, SetIntStr, jsonable_encoder
@@ -446,7 +447,7 @@ class APIRoute(routing.Route):
                 get_parameterless_sub_dependant(depends=depends, path=self.path_format),
             )
         self.body_field = get_body_field(dependant=self.dependant, name=self.unique_id)
-        self.hash_val = f"path:{self.path};methods:{self.methods}"
+        self.hash_val = get_path_hash_val(self.path, self.methods)
         self.app = request_response(self.get_route_handler())
 
     def get_route_handler(self) -> Callable[[Request], Coroutine[Any, Any, Response]]:
@@ -780,6 +781,10 @@ class APIRouter(routing.Router):
                 )
             elif isinstance(route, routing.Route):
                 methods = list(route.methods or [])
+                hash_val = get_path_hash_val(route.path, route.methods)
+                if hash_val in self.added_routes:
+                    raise RouteAlreadyExistsError(route.name)
+                self.added_routes.add(hash_val)
                 self.add_route(
                     prefix + route.path,
                     route.endpoint,
diff --git a/tests/test_include_duplicate_path_route.py b/tests/test_include_duplicate_path_route.py
new file mode 100644
index 000000000..ca191ffdd
--- /dev/null
+++ b/tests/test_include_duplicate_path_route.py
@@ -0,0 +1,121 @@
+import pytest
+from fastapi import APIRouter, FastAPI
+from fastapi.exceptions import RouteAlreadyExistsError
+
+
+def test_app_router_with_duplicate_path():
+    with pytest.raises(RouteAlreadyExistsError):
+        app = FastAPI()
+
+        @app.get("/items/")
+        def read_items():
+            return
+
+        @app.get("/items/")
+        def read_items2():
+            return
+
+
+def test_sub_with_duplicate_path():
+    with pytest.raises(RouteAlreadyExistsError):
+        app = FastAPI()
+        router = APIRouter()
+
+        @router.get("/items/")
+        def read_items():
+            return
+
+        @router.get("/items/")
+        def read_items2():
+            return
+
+        app.include_router(router)
+
+
+def test_mix_app_sub_with_duplicate_path():
+    with pytest.raises(RouteAlreadyExistsError):
+        app = FastAPI()
+        router = APIRouter()
+
+        @app.get("/items/")
+        def read_items():
+            return
+
+        @router.get("/items/")
+        def read_items2():
+            return
+
+        app.include_router(router)
+
+
+def test_sub_route_direct_duplicate_path():
+    with pytest.raises(RouteAlreadyExistsError):
+        app = FastAPI()
+        router = APIRouter()
+
+        @router.route("/items/")
+        def read_items():
+            return
+
+        @router.route("/items/")
+        def read_items2():
+            return
+
+        app.include_router(router)
+
+
+def test_app_router_with_duplicate_path_different_method():
+    app = FastAPI()
+
+    @app.get("/items/")
+    def read_items():
+        return
+
+    @app.post("/items/")
+    def read_items2():
+        return
+
+
+def test_sub_with_duplicate_path_different_method():
+    app = FastAPI()
+    router = APIRouter()
+
+    @router.get("/items/")
+    def read_items():
+        return
+
+    @router.post("/items/")
+    def read_items2():
+        return
+
+    app.include_router(router)
+
+
+def test_mix_app_sub_with_duplicate_different_method():
+    app = FastAPI()
+    router = APIRouter()
+
+    @app.get("/items/")
+    def read_items():
+        return
+
+    @router.post("/items/")
+    def read_items2():
+        return
+
+    app.include_router(router)
+
+
+def test_sub_route_direct_duplicate_path_different_method():
+    app = FastAPI()
+    router = APIRouter()
+
+    @router.route("/items/")
+    def read_items():
+        return
+
+    @router.route("/items/", methods=["POST"])
+    def read_items2():
+        return
+
+    app.include_router(router)