Anyone know if there is anything built into rails to the effect of validates_signularity_of :string? I can't find any documentation of anything like this, but just wanted to check. I want to validate that a string the user can enter in is always a singular word.
One way would be to leverage the singularize method.
If singularizing a string results in the same string, the string is already singular. Otherwise, it is plural.
A custom validator like the following might work:
class SingularValidator < ActiveModel::EachValidator
def validate_each(object, attribute, value)
unless value.to_s.singularize == value
object.errors[attribute] << (options[:message] || "is not singular")
end
end
end
Then in your model:
validates :column_name, :singular => true
Credit:
Basic structure of a custom validator extracted from Ryan's Railscast #211
Related
I'm relatively new to testing and very new to Rails 4 and rSpec. I am trying to test a controller that uses Devise for authentication and I am stuck. All of the examples I can find are for Rails 3.
I'm using Rails 4.0.3, Devise 3.2.3, rSpec 2.14.1 and FactoryGirl 4.4.0.
class LessonPlansController < ApplicationController
before_action :authenticate_user!
# GET /lesson_plans
def index
#lesson_plans = current_user.lesson_plans.to_a
end
.
.
.
private
# Use callbacks to share common setup or constraints between actions.
def set_lesson_plan
#lesson_plan = LessonPlan.find(params[:id])
end
# Only allow a trusted parameter "white list" through.
def lesson_plan_params
params[:lesson_plan]
end
def lesson_plan_params
params.require(:lesson_plan).permit(:title, :synopsis)
end
end
Here are my factory definitions: (Maybe I don't need to define user_id in the lesson_plan factory?)
FactoryGirl.define do
factory :user do
sequence( :username ) { |n| "user#{n}" }
sequence( :email ) { |n| "foo#{n}#example.com" }
password 'foobarbaz'
password_confirmation 'foobarbaz'
created_at Time.now
updated_at Time.now
end
end
FactoryGirl.define do
factory :lesson_plan do
user_id 1
title "The French Revolution"
synopsis "Background and events leading up to the French Revolution"
end
end
And the test part is where I get stuck.
describe LessonPlansController do
let(:valid_attributes) { { } }
let(:valid_session) { {} }
# describe "GET index" do
it "assigns all lesson_plans as #lesson_plans" do
user=FactoryGirl.create(:user)
sign_in user
lesson_plan = LessonPlan.create! valid_attributes
get :index, {}, valid_session
assigns(:lesson_plans).should eq([lesson_plan])
end
end
I'm not sure what to put in valid_attributes and valid_session (or if I even need them). The test will get as far as signing in the user, but will fail on creation of the lesson_plan. Admittedly this is the default/generated test for rSpec, but I am not sure how to proceed.
Examples I have seen use a before block to set up the user. I haven't been able to find anything on the Devise wiki page covering how to write basic rSpec tests for a controller that requires the user to be logged in. Any pointers would be greatly appreciated!
"I'm not sure what to put in valid_attributes and valid_session (or if I even need them)."
Well that depends what you're testing for.. Say you're testing validations & want to ensure that a record not be created if x column is set to null... then you could try to specifically create a record with invalid attributes (e.g. column: nil) and expect the result to not return true; maybe you want to ensure that it IS created with valid attributes.
You can btw, use `attributes_for(:factory_name)`` since you're using FactoryGirl. And no you don't necessarily need to specify the user's id in your lesson plan factory; unless you always want it to reference user 1. You can simply reference user with no value. Check out http://everydayrails.com/2012/03/12/testing-series-intro.html and especially parts 3-5 for an introduction to testing with RSPec.. I found this a pretty easy to follow guide when I was getting started.
I would like to show some extra info in error messages resulting from a failed validation. For example suppose I have a class Book with the following validation
validates :name, presence: true, uniqueness: true
When someone tries to insert a book by the same name the following error message is returned
{"name":["has already been taken"]}
Instead I wanna show
{"name":["Book 'Great Expectaions' has already been taken at id:7"]}
Right now to make this happen I have to remove the uniqueness validation that I mentioned above and do the following
validate do |book|
existing_book = Book.find_by_name(book.name)
if existing_book
book.errors.add(:name, "#{existing_book.name} already exists at id: #{existing_book.id}")
end
end
Is there a way to get custom error messages like above without writing a custom uniqueness validation? I was thinking something along the lines of
validates :name, presence: true, uniqueness: {message: "#{self.name} already exists at id: #{Book.find_by_name(self.name).id}"
But this does not seem to work as self.name returns 'Book'. Is there a way to access the passed parameters in this context?
You'll have to do this as a custom validation. I would do it like so:
validate :name_is_unique
private
def name_is_unique
errors.add(:name, "#{other_book.name} already exists at id: #{other_book.id}") if other_book = Book.find_by_name(name)
end
The issue isn't really that you can't include the current model attributes in your validation, its that there's no 'one-liner' way to include another model. The good news is, that's what the validate method is for.
If it bothers you to have this in your model, just write a custom validator so it can be re-used application-wide.
Suppose I have a model user, which has a uniqueness constraint on the email field
If I call Factory(:user) once all is well, but if I call it a second time it'll fail with an "entry already exists" error.
I'm currently using a simple helper to search for an existing entry in the DB before creating the factory...and calling any factory I make through that helper.
It works, but it's not entirely elegant, and considering how common I assume this problem must be, I'm guessing there's a better solution. So, is there an inbuilt way in factory girl to return_or_create a factory, instead of just charging ahead with create()? If not, how do most folk avoid duplicate entries with their factories?
Simple answer: use factory.sequence
If you have a field that needs to be unique you can add a sequence in factory_girl to ensure that it is never the same:
Factory.define :user do |user|
sequence(:email){|n| "user#{n}#factory.com" }
user.password{ "secret" }
end
This will increment n each time in order to produce a unique email address such as user52#factory.com. (See https://github.com/thoughtbot/factory_girl/wiki/Usage for more info)
However this isn't always great in Rails.env.development...
Over time I have found that this is not actually the most useful way to create unique email addresses. The reason is that while the factory is always unique for your test environment it's not always unique for your development environment and n resets itself as you start the environment up and down. In :test this isn't a problem because the database is wiped but in :development you tend to keep the same data for a while.
You then get collisions and find yourself having to manually override the email to something you know is unique which is annoying.
Often more useful: use a random number
Since I call u = Factory :user from the console on a regular basis I go instead with generating a random number. You're not guaranteed to avoid collisions but in practice it hardly ever happens:
Factory.define :user do |user|
user.email {"user_#{Random.rand(1000).to_s}#factory.com" }
user.password{ "secret" }
end
N.B. You have to use Random.rand rather than rand() because of a collision (bug?) in FactoryGirl [https://github.com/thoughtbot/factory_girl/issues/219](see here).
This frees you to create users at will from the command line regardless of whether there are already factory generated users in the database.
Optional extra for making email testing easier
When you get into email testing you often want to verify that an action by a particular user triggered an email to another user.
You log in as Robin Hood, send an email to Maid Marion and then go to your inbox to verify it. What you see in your inbox is something from user_842#factory.com. Who the hell is that?
You need to go back to your database to check whether the email was sent / received by whomever you expected it to be. Again this is a bit of a pain.
What I like to do instead is to generate the email using the name of the Factory user combined with a random number. This makes it far easier to check who things are coming from (and also makes collisions vanishingly unlikely). Using the Faker gem (http://faker.rubyforge.org/) to create the names we get:
Factory.define :user do |user|
user.first_name { Faker::Name::first_name }
user.last_name { Faker::Name::last_name }
user.email {|u| "#{u.first_name}_#{u.last_name}_#{Random.rand(1000).to_s}#factory.com" }
end
finally, since Faker sometimes generates names that aren't email-friendly (Mike O'Donnell) we need to whitelist acceptable characters: .gsub(/[^a-zA-Z1-10]/, '')
Factory.define :user do |user|
user.first_name { Faker::Name::first_name }
user.last_name { Faker::Name::last_name }
user.email {|u| "#{u.first_name.gsub(/[^a-zA-Z1-10]/, '')}_#{u.last_name.gsub(/[^a-zA-Z1-10]/, '')}_#{Random.rand(1000).to_s}#factory.com" }
end
This gives us personable but unique emails such as robin_hood_341#factory.com and maid_marion_10#factory.com
Here's what I do to force the 'n' in my factory girl sequence to be the same as that object's id, and thereby avoid collisions:
First, I define a method that finds what the next id should be in app/models/user.rb:
def self.next_id
self.last.nil? ? 1 : self.last.id + 1
end
Then I call User.next_id from spec/factories.rb to start the sequence:
factory :user do
association(:demo)
association(:location)
password "password"
sequence(:email, User.next_id) {|n| "darth_#{n}#sunni.ru" }
end
I found this a nice way to be sure the tests will always pass.
Otherwise you can not be sure the 100% of the times you will create a unique email.
FactoryGirl.define do
factory :user do
name { Faker::Company.name }
email { generate(:email) }
end
sequence(:email) do
gen = "user_#{rand(1000)}#factory.com"
while User.where(email: gen).exists?
gen = "user_#{rand(1000)}#factory.com"
end
gen
end
end
If you only need to generate a few values for attributes, you can also add a method to String, which keeps track of the prior strings used for an attribute. You could then do something like this:
factory :user do
fullname { Faker::Name.name.unique('user_fullname') }
end
I use this approach for seeding. I wanted to avoid sequence numbers, because they do not look realistic.
Here the String extension which makes this happen:
class String
# Makes sure that the current string instance is unique for the given id.
# If you call unique multiple times on equivalent strings, this method will suffix it with a upcounting number.
# Example:
# puts "abc".unique("some_attribute") #=> "abc"
# puts "abc".unique("some_attribute") #=> "abc-1"
# puts "abc".unique("some_attribute") #=> "abc-2"
# puts "abc".unique("other") #=> "abc"
#
# Internal:
# We keep a data structure of the following format:
# ##unique_values = {
# "some_for_id" => { "used_string_1" : 1, "used_string_2": 2 } # the numbers represent the counter to be used as suffix for the next item
# }
def unique(for_id)
##unique_values ||= {} # initialize structure in case this method was never called before
##unique_values[for_id] ||= {} # initialize structure in case we have not seen this id yet
counter = ##unique_values[for_id][self] || 0
result = (counter == 0) ? self : "#{self}-#{counter}"
counter += 1
##unique_values[for_id][self] = counter
return result
end
end
Caution: This should not be used for lots of attributes, since we track all prior strings (optimizations possible).
Let's say I have a model class with 3 attributes. I'd like to make sure that at least one of the three is present.
Do I have to write a custom validation for this? Or is there a way to do this with an existing validation helper?
You will need to write a custom validator for this. All you need to do is subclass ActiveModel::Validator and implement a validate(record) method, which adds to the record's errors hash in the event of an error:
class YourValidator < ActiveModel::Validator
def validate(record)
if (your_failure_condition_here)
record.errors[:base] << "Your error message"
end
end
end
And then use the validator in your model like so (assuming you've appropriately loaded your validator class):
class YourModel
validates_with YourValidator
end
A custom validation in your model would be the cleanest way in my opinion:
class Model
validate :at_least_one_present
def at_least_one_present
if(they_dont_exist)
errors.add("need at least one of these fields")
end
end
end
Reference: Creating custom validation methods
I need to apply validation to a Model so that 2 integer values in the record, minimum and maximum, form an inclusive range (ex. 2 and 3 are ok, but 4 and 1 are not). From what I understand, since I need to validate 2 values against each other in the same record, I have to use ActiveModel::Validator (and not ActiveModel::EachValidator). So, I try the following:
Model (app/models/position.rb):
class Position < ActiveRecord::Base
validates_with InclusiveRangeValidator
end
Validator (app/lib/validators/inclusive_range_validator.rb):
class InclusiveRangeValidator < ActiveModel::Validator
def validate(record)
record.errors[:base] << "#{record.minimum} and #{record.maximum} do not form a valid inclusive range." unless record.minimum < record.maximum
end
end
I've read that Rails 3.0.5 doesn't automatically load the lib directory anymore, so I added this line in config/application.rb:
config.autoload_path += %W({config.root}/lib)
And then I reset the rails server so it'll take the change to config/application.rb. I run my unit tests, which tries to exercise the model to prove this validation works. I get this error:
uninitialized constant: Position::InclusiveRangeValidator (NameError)
What I think is happening is that Rails is not recognizing/finding my custom validator class, and so it assumes InclusiveRangeValidator is a constant in the class that it's referenced in. But, I thought the change I made to config/application.rb would put my validator in the load path so that it would be available.
I've gone through the other posts on StackOverflow and didn't come up with a solution, and I've read the API docs on validators, to no avail. I've got to be doing something simple and stupid, but I can't see what the issue is. Any help?
EDIT:
After more searching, I discovered that I don't need a custom validator at all, as I can accomplish the same goal with this:
validates :minimum, :numericality => {:greater_than_or_equal_to => 0 }
validates :maximum, :numericality => {:greater_than => :minimum }
However, the question still remains as to why Rails can't locate the custom validation class.
Once, I changed the line in application.rb to:
config.autoload_paths += %W[#{config.root}/lib/validators/]
Rails was able to find the right path to load my custom validator. I made the mistake of assuming Rails would automatically recurse the directory structure, this is evidently not the case.