Refactor phone number validation and enhance test coverage

Improved phone number validation logic with stricter rules and better error messages in `UserBase`. Updated access token expiration to 1 day in config. Added extensive tests for phone number validation, including valid and invalid cases across different formats.

backend/app/core/config.py

@@ -41,7 +41,7 @@ class Settings(BaseSettings):
     # JWT configuration
     SECRET_KEY: str = "your_secret_key_here"
     ALGORITHM: str = "HS256"
-    ACCESS_TOKEN_EXPIRE_MINUTES: int = 30
+    ACCESS_TOKEN_EXPIRE_MINUTES: int = 1440 # 1 day
 
     # CORS configuration
     BACKEND_CORS_ORIGINS: List[str] = ["http://localhost:3000"]

backend/app/schemas/users.py

@@ -48,14 +48,38 @@ class UserUpdate(BaseModel):
     preferences: Optional[Dict[str, Any]] = None
 
     @field_validator('phone_number')
-    @classmethod
     def validate_phone_number(cls, v: Optional[str]) -> Optional[str]:
         if v is None:
             return v
-        # Simple regex for phone validation
-        if not re.match(r'^\+?[0-9\s\-\(\)]{8,20}$', v):
-            raise ValueError('Invalid phone number format')
-        return v
+
+        # Return early for empty strings or whitespace-only strings
+        if not v or v.strip() == "":
+            raise ValueError('Phone number cannot be empty')
+
+        # Remove all spaces and formatting characters
+        cleaned = re.sub(r'[\s\-\(\)]', '', v)
+
+        # Basic pattern:
+        # Must start with + or 0
+        # After + must have at least 8 digits
+        # After 0 must have at least 8 digits
+        # Maximum total length of 15 digits (international standard)
+        # Only allowed characters are + at start and digits
+        pattern = r'^(?:\+[0-9]{8,14}|0[0-9]{8,14})$'
+
+        if not re.match(pattern, cleaned):
+            raise ValueError('Phone number must start with + or 0 followed by 8-14 digits')
+
+        # Additional validation to catch specific invalid cases
+        if cleaned.count('+') > 1:
+            raise ValueError('Phone number can only contain one + symbol at the start')
+
+        # Check for any non-digit characters (except the leading +)
+        if not all(c.isdigit() for c in cleaned[1:]):
+            raise ValueError('Phone number can only contain digits after the prefix')
+
+        return cleaned
+
 
 
 class UserInDB(UserBase):