fix: Respond with field error on existing email id in signup api

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## unreleased
 
+## [0.11.10] - 2022-12-12
+
+-   Fixes issue of sign up API not sending a `FIELD_ERROR` response in case of duplicate email: https://github.com/supertokens/supertokens-python/issues/264
+
 ## [0.11.9] - 2022-12-06
 
 -   Fixes issue where if send_email is overridden with a different email, it will reset that email.

setup.py

@@ -70,7 +70,7 @@
 
 setup(
     name="supertokens_python",
-    version="0.11.9",
+    version="0.11.10",
     author="SuperTokens",
     license="Apache 2.0",
     author_email="[email protected]",

supertokens_python/constants.py

@@ -12,7 +12,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 SUPPORTED_CDI_VERSIONS = ["2.9", "2.10", "2.11", "2.12", "2.13", "2.14", "2.15"]
-VERSION = "0.11.9"
+VERSION = "0.11.10"
 TELEMETRY = "/telemetry"
 USER_COUNT = "/users/count"
 USER_DELETE = "/user/remove"

supertokens_python/recipe/emailpassword/api/signup.py

@@ -15,6 +15,14 @@
 
 from typing import TYPE_CHECKING, Any
 
+from ..exceptions import raise_form_field_exception
+from supertokens_python.recipe.emailpassword.interfaces import (
+    SignUpOkResult,
+    SignUpPostEmailAlreadyExistsError,
+)
+from supertokens_python.types import GeneralErrorResponse
+from ..types import ErrorFormField
+
 if TYPE_CHECKING:
     from supertokens_python.recipe.emailpassword.interfaces import (
         APIOptions,
@@ -43,4 +51,17 @@ async def handle_sign_up_api(api_implementation: APIInterface, api_options: APIO
         form_fields, api_options, user_context
     )
 
-    return send_200_response(response.to_json(), api_options.response)
+    if isinstance(response, SignUpOkResult):
+        return send_200_response(response.to_json(), api_options.response)
+    if isinstance(response, GeneralErrorResponse):
+        return send_200_response(response.to_json(), api_options.response)
+    if isinstance(response, SignUpPostEmailAlreadyExistsError):
+        return raise_form_field_exception(
+            "EMAIL_ALREADY_EXISTS_ERROR",
+            [
+                ErrorFormField(
+                    id="email",
+                    error="This email already exists. Please sign in instead.",
+                )
+            ],
+        )

supertokens_python/recipe/emailpassword/exceptions.py

@@ -13,15 +13,15 @@
 # under the License.
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Any, Dict, List
+from typing import TYPE_CHECKING, Any, Dict, List, NoReturn
 
 from supertokens_python.exceptions import SuperTokensError
 
 if TYPE_CHECKING:
     from .types import ErrorFormField
 
 
-def raise_form_field_exception(msg: str, form_fields: List[ErrorFormField]):
+def raise_form_field_exception(msg: str, form_fields: List[ErrorFormField]) -> NoReturn:
     raise FieldError(msg, form_fields)
 
 

tests/emailpassword/test_signup.py

@@ -0,0 +1,60 @@
+# Copyright (c) 2021, VRAI Labs and/or its affiliates. All rights reserved.
+#
+# This software is licensed under the Apache License, Version 2.0 (the
+# "License") as published by the Apache Software Foundation.
+#
+# You may not use this file except in compliance with the License. You may
+# obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+from fastapi import FastAPI
+import json
+from fastapi.testclient import TestClient
+from pytest import fixture, mark
+from supertokens_python import init
+from supertokens_python.framework.fastapi import get_middleware
+from supertokens_python.recipe import emailpassword, session
+from tests.utils import (
+    get_st_init_args,
+    setup_function,
+    start_st,
+    teardown_function,
+    sign_up_request,
+)
+
+_ = setup_function  # type: ignore
+_ = teardown_function  # type: ignore
+
+pytestmark = mark.asyncio
+
+
+@fixture(scope="function")
+async def app():
+    app = FastAPI()
+    app.add_middleware(get_middleware())
+
+    return TestClient(app)
+
+
+async def test_field_error_on_existing_email_signup(app: TestClient):
+    init_args = get_st_init_args([emailpassword.init(), session.init()])
+    init(**init_args)
+    start_st()
+
+    response = json.loads(sign_up_request(app, "[email protected]", "validpass123").text)
+    assert response["status"] == "OK"
+
+    response = json.loads(sign_up_request(app, "[email protected]", "validpass123").text)
+    assert response == {
+        "status": "FIELD_ERROR",
+        "formFields": [
+            {
+                "id": "email",
+                "error": "This email already exists. Please sign in instead.",
+            }
+        ],
+    }