Another fixture replacement. Gets you some methods (new_*, create_* and valid_*_attributes) methods and some confidence.

View the RDoc (still underway, but has a bit of helpful stuff)

Recommend Me on the Working with Rails


Fixjour has some developer dependencies. Install them as shown below, and run rake to make sure the tests pass. Then dive in!

fixjour:$ gem build fixjour.gemspec
fixjour:$ sudo gem install --development fixjour
fixjour:$ rake
Do the tests pass?

The focus of this project is liberation through constraints.

It uses the bits of object mother systems that worked well for me in the past, and actively discourages the bits that have caused me pain.

The constraints:

One builder per model

If you try to define a builder more than once per model, you’ll run into a Fixjour::RedundantBuilder error. One builder per model decreases confusion.

No redundant object creation methods

If you try to define a method that’s already been defined by a Fixjour builder, you’ll run into a Fixjour::RedundantBuilder error. If you find the need to alter the behavior of a builder for a particular set of tests, you should just wrap the creation methods defined by Fixjour, preferably with a name that describes how the new method is different from the Fixjour method.

Processing the overrides hash is bad

If you want to mess with the overrides hash that can be passed into any of the creation methods, you must use the process method (see below). To enforce this, the delete method is actually private for the overrides hash.

What it gets you:

With this setup:

Fixjour do
  define_builder(Person) do |klass, overrides| => 'Pat', :age => 22)

include Fixjour

You get:


The new_person method basically just returns the result of your builder block, which should always return an unsaved instance of the model class. You can pass it overrides in a hash like so: new_person(:name => nil).


The create_person method calls new_person, passing in any overrides you pass it, calls save! on the result, and returns the saved object.


The valid_person_attributes returns a hash of valid person attributes that are derived from the new_person method, and ideal for things like testing controllers. It can also take attribute override options like so: valid_person_attributes(:name => nil).


You specify builder sets for your ActiveRecord models in a Fixjour block using the define_builder helper, which can be used in one of two ways:

Using a builder block

Pass define_builder a model class for which you want a new set of creation methods, and a block which returns a new valid model object. The block will be passed two arguments: a proxy object for your class, and an overrides hash. If you call new on the class proxy, it will return a new instance of the class, with whatever attributes you specify as defaults. It will also automatically merge any override options in all of the methods generated by Fixjour.


define_builder(Person) do |klass, overrides| => "Pat", :age => 22)

If you want to process an option in the overrides hash, you can use the process method:

define_builder(Person) do |klass, overrides|
  overrides.process(:child) do |is_child|
    overrides[:age] = 14 if is_child
  end => "Pat", :age => 22)

# the default
person = new_person
person.age # => 22

# using the override
person = new_person(:child => true)
person.age  # => 14

In the above example, the :child key will be deleted from the overrides hash and made available as the is_child block argument where you can handle things accordingly.

Note: The delete method is private on the overrides hash passed into the builder block. This is meant to encourage you to only use the process method instead. Why? First, because processing the overrides hash is a smell. Deal with it. Second, using the process method provides some indication to readers that you’re screwing with the overrides hash, and that’s a good thing.

attr_protected fields

If you have fields that cannot be mass-assigned, use the protected helper:

define_builder(Article) do |klass, overrides| klass.protected :author :title => “The title”, :body => “good”, :author => new_user end

If you use the protected helper to declare attr_protected fields, you can then treat them the same as any other field in your test methods.

With Associations

To specify an associated object, you can call that object’s new_* method:

Fixjour do
  define_builder(Post) do |klass, overrides| => 'a post', :body => 'texted')
  define_builder(Comment) do |klass, overrides| => 'Oh ok!', :post => new_post)

include Fixjour # => 'a post'

Note that it’s never a good idea to use a create_* method in a build block.

Verifying your setups

Fixjour requires more work on your part, so it also includes a way to verify that your creation methods are behaving the way they should. Call Fixjour.verify! to ensure the following things:

  1. Creation methods are returning valid objects by default.
  2. new_* methods are returning new records.
  3. new_* and create_* methods return instances of the correct class.

Recommended usage with RSpec and Cucumber

If you want to use Fixjour with RSpec and Cucumber you probably want to avoid adding the builder methods onto Object directly. To do this you should first create a file where your Fixjour builder definitions can live. Say for example you put it at spec/fixjour_builders.rb. To take advantage of these builders from RSpec use the following code in your spec_helper.rb:

require File.expand_path(File.dirname(__FILE__) + "/fixjour_builders.rb")

Spec::Runner.configure do |config|
  config.include(Fixjour) # This will add the builder methods to your ExampleGroups and not pollute Object

To use the same builders in Cucumber you simply need to include Fixjour into your World object from features/support/env.rb:

require File.expand_path(File.dirname(__FILE__) +'/../../spec/fixjour_builders.rb')
World { |world| world.extend(Fixjour) }

Be sure to do this after you define your World object. So, if you are using Rails you should include Fixjour after you require ‘cucumber/rails/world’.

In Cucumber version and later you need to pass in a module to the World method to extend it:

require File.expand_path(File.dirname(__FILE__) +'/../../spec/fixjour_builders.rb')

(See the Cucumber::StepMother#World RDoc or


  • Pat Maddox – Sparked the original idea and fixed my bugs
  • Ben Mabey – Added docs and fixed my bugs
  • Aaron Quint – Pointed out valid attrs problem and fixed my bugs


  • There should be a Builder class.

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© Copyright 2008 Pat Nakajima, released under MIT License.