Fix #245 : handle email as case insensitive while retrieving user in DB (#250)

* Add unit tests to enforce email case insensitivity

* Handle email as case insentitive while retrieving user in DB

* Apply isort/black

* Add migration doc

fastapi_users/db/mongodb.py

@@ -28,7 +28,9 @@ class MongoDBUserDatabase(BaseUserDatabase[UD]):
         return self.user_db_model(**user) if user else None
 
     async def get_by_email(self, email: str) -> Optional[UD]:
-        user = await self.collection.find_one({"email": email})
+        user = await self.collection.find_one(
+            {"email": {"$regex": email, "$options": "i"}}
+        )
         return self.user_db_model(**user) if user else None
 
     async def get_by_oauth_account(self, oauth: str, account_id: str) -> Optional[UD]:

fastapi_users/db/sqlalchemy.py

@@ -3,7 +3,7 @@ from typing import Mapping, Optional, Type
 
 from databases import Database
 from pydantic import UUID4
-from sqlalchemy import Boolean, Column, ForeignKey, Integer, String, Table, select
+from sqlalchemy import Boolean, Column, ForeignKey, Integer, String, Table, func, select
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.ext.declarative import declared_attr
 from sqlalchemy.types import CHAR, TypeDecorator
@@ -120,7 +120,9 @@ class SQLAlchemyUserDatabase(BaseUserDatabase[UD]):
         return await self._make_user(user) if user else None
 
     async def get_by_email(self, email: str) -> Optional[UD]:
-        query = self.users.select().where(self.users.c.email == email)
+        query = self.users.select().where(
+            func.lower(self.users.c.email) == func.lower(email)
+        )
         user = await self.database.fetch_one(query)
         return await self._make_user(user) if user else None
 

fastapi_users/db/tortoise.py

@@ -77,19 +77,19 @@ class TortoiseUserDatabase(BaseUserDatabase[UD]):
             return None
 
     async def get_by_email(self, email: str) -> Optional[UD]:
-        try:
-            query = self.model.get(email=email)
+        query = self.model.filter(email__iexact=email).first()
 
-            if self.oauth_account_model is not None:
-                query = query.prefetch_related("oauth_accounts")
+        if self.oauth_account_model is not None:
+            query = query.prefetch_related("oauth_accounts")
 
-            user = await query
-            user_dict = await user.to_dict()
+        user = await query
 
-            return self.user_db_model(**user_dict)
-        except DoesNotExist:
+        if user is None:
             return None
 
+        user_dict = await user.to_dict()
+        return self.user_db_model(**user_dict)
+
     async def get_by_oauth_account(self, oauth: str, account_id: str) -> Optional[UD]:
         try:
             query = self.model.get(