Single Table Inheritance Errors - ActiveRecord::SubclassNotFound - ruby-on-rails

Question

My intent is to implement STI with two types: Staff and Clinician. My previous implementation was using roles with enums, and after doing my best to follow answers to similar questions, take out all references in tests etc. to enum roles and replace with references to types , I am getting many versions of the following error when I run my testing suite:
ERROR["test_valid_signup_information_with_account_activation", UsersSignupTest, 1.01794000000001]
test_valid_signup_information_with_account_activation#UsersSignupTest (1.02s)
ActiveRecord::SubclassNotFound: ActiveRecord::SubclassNotFound: The single-table inheritance mechanism failed to locate the subclass: 'Staff'. This error is raised because the column 'type' is reserved for storing the class in case of inheritance. Please rename this column if you didn't intend it to be used for storing the inheritance class or overwrite User.inheritance_column to use another column for that information.
app/controllers/users_controller.rb:19:in `create'
test/integration/users_signup_test.rb:27:in `block (2 levels) in <class:UsersSignupTest>'
test/integration/users_signup_test.rb:26:in `block in <class:UsersSignupTest>'
Here are a couple areas where I am confused that could potentially be hiding issues:
In my user model user.rb, I think I am defining the sub Classes correctly (Staff and Clinician), but I'm unsure if I'm wrapping everything correctly. Does all the other code have to be contained in one of these classes? Am I misusing "end"?
class User < ApplicationRecord
end
class Staff < User
end
class Clinician < User
end
belongs_to :university
has_many :referral_requests
attr_accessor :remember_token, :activation_token, :reset_token
before_save :downcase_email
before_create :create_activation_digest
validates :name, presence: true, length: { maximum: 50 }
VALID_EMAIL_REGEX = /\A[\w+\-.]+#[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i
validates :email, presence: true, length: { maximum: 255 },
format: { with: VALID_EMAIL_REGEX },
uniqueness: { case_sensitive: false }
validates :type, presence: true
validates :university_id, presence: true, if: lambda { self.type == 'Staff' }
has_secure_password
validates :password, presence: true, length: { minimum: 6 }, allow_nil: true
# Returns the hash digest of the given string.
def User.digest(string)
cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
BCrypt::Engine.cost
BCrypt::Password.create(string, cost: cost)
end
# Returns a random token.
def User.new_token
SecureRandom.urlsafe_base64
end
# Remembers a user in the database for use in persistent sessions.
def remember
self.remember_token = User.new_token
update_attribute(:remember_digest, User.digest(remember_token))
end
# Returns true if the given token matches the digest.
def authenticated?(remember_token)
return false if remember_digest.nil?
BCrypt::Password.new(remember_digest).is_password?(remember_token)
end
# Forgets a user.
def forget
update_attribute(:remember_digest, nil)
end
# Returns true if the given token matches the digest.
def authenticated?(attribute, token)
digest = send("#{attribute}_digest")
return false if digest.nil?
BCrypt::Password.new(digest).is_password?(token)
end
# Activates an account.
def activate
update_attribute(:activated, true)
update_attribute(:activated_at, Time.zone.now)
end
# Sends activation email.
def send_activation_email
UserMailer.account_activation(self).deliver_now
end
# Sets the password reset attributes.
def create_reset_digest
self.reset_token = User.new_token
update_attribute(:reset_digest, User.digest(reset_token))
update_attribute(:reset_sent_at, Time.zone.now)
end
# Sends password reset email.
def send_password_reset_email
UserMailer.password_reset(self).deliver_now
end
# Returns true if a password reset has expired.
def password_reset_expired?
reset_sent_at < 2.hours.ago
end
def feed
ReferralRequest.where("user_id = ?", id)
end
private
# Converts email to all lower-case.
def downcase_email
self.email = email.downcase
end
# Creates and assigns the activation token and digest.
def create_activation_digest
self.activation_token = User.new_token
self.activation_digest = User.digest(activation_token)
end
end
Here's the specific test code that is failing (one of many in the test suite that are failing - all the user parameters are defined similarly though). Am I passing the staff parameter appropriately?
test "valid signup information with account activation" do
get signup_path
assert_difference 'User.count', 1 do
post users_path, params: { user: { name: "Example User",
email: "user#example.com",
university_id: 1 ,
type: "Staff",
password: "password",
password_confirmation: "password" } }
Here is my users table schema:
create_table "users", force: :cascade do |t|
t.string "name"
t.string "email"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.string "password_digest"
t.string "remember_digest"
t.string "activation_digest"
t.boolean "activated", default: false
t.datetime "activated_at"
t.string "reset_digest"
t.datetime "reset_sent_at"
t.integer "university_id"
t.integer "role"
t.string "type"
t.index ["email"], name: "index_users_on_email", unique: true
end
Thanks very much for any ideas! I ask a lot of questions on here but it's only after trying to work through similar answers for quite a while.

Answer 1

Assuming that the code sample above is accurate, you are seeing this error because the user.rb file is invalid Ruby and failing to parse. You should also be seeing an interpreter error about that.
class User < ApplicationRecord
belongs_to :university
has_many :referral_requests
attr_accessor :remember_token, :activation_token, :reset_token
before_save :downcase_email
before_create :create_activation_digest
validates :name, presence: true, length: { maximum: 50 }
VALID_EMAIL_REGEX = /\A[\w+\-.]+#[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i
validates :email, presence: true, length: { maximum: 255 },
format: { with: VALID_EMAIL_REGEX },
uniqueness: { case_sensitive: false }
validates :type, presence: true
has_secure_password
validates :password, presence: true, length: { minimum: 6 }, allow_nil: true
# etc...
end
class Staff < User
validates :university_id, presence: true
end
class Clinician < User
end
Standard class-inheritance practices apply, so if there is code in there that is only appropriate for a specific subclass it should move there (e.g. university_id validation moving to Staff).
# Returns the hash digest of the given string.
def User.digest(string)
cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
BCrypt::Engine.cost
BCrypt::Password.create(string, cost: cost)
end
# Returns a random token.
def User.new_token
SecureRandom.urlsafe_base64
end
These should be written as
def self.digest(string)
# ...
end
def self.new_token
# ...
end
or, alternatively,
class << self
def digest(string)
# ...
end
def new_token
# ...
end
end