ActiveMocker

Create mocks from active record models without loading rails or running a database.

Installation

Add this line to your application's Gemfile:

gem 'active_mocker'

And then execute:

$ bundle

Or install it yourself as:

$ gem install active_mocker

Usage

#db/schema.rb

ActiveRecord::Schema.define(version: 20140327205359) do

  create_table "people", force: true do |t|
    t.integer  "account_id"
    t.string   "first_name",        limit: 128
    t.string   "last_name",         limit: 128
    t.string   "address",           limit: 200
    t.string   "city",              limit: 100
  end

end

#app/models/person.rb

class Person < ActiveRecord::Base
  belongs_to :account

  def bar(name, type=nil)
    puts name
  end

  def self.bar
  end

end

require 'active_mocker'

ActiveMocker.configure do |config|
  # Required Options
  config.schema_file = "#{APP_ROOT}/db/schema.rb"
  config.model_dir   = "#{APP_ROOT}/app/models"
  # Additional Options
  config.schema_attributes   = true  #default
  config.model_attributes    = true  #default
  # Logging
  config.log_level = Logger::WARN       #default
end

ActiveMocker.mock('Person')
    => PersonMock

PersonMock.column_names
    => ["account_id", "first_name", "last_name", "address", "city"]

person_mock = PersonMock.new(first_name: "Dustin", last_name: "Zeisler", account: ActiveMocker.mock('Account').new)
    => #<PersonMock @first_name="Dustin", @last_name="Zeisler">

 person_mock.first_name
    => "Dustin"

When schema.rb changes, the mock fails

 #db/schema.rb

 ActiveRecord::Schema.define(version: 20140327205359) do

   create_table "people", force: true do |t|
     t.integer  "account_id"
     t.string   "f_name",        limit: 128
     t.string   "l_name",        limit: 128
     t.string   "address",       limit: 200
     t.string   "city",          limit: 100
   end

 end

 person_mock = PersonMock.new(first_name: "Dustin", last_name: "Zeisler", account: AccountMock.new)
         => NoMethodError: undefined method `first_name=' for #<PersonMock:0x007f860abf6b10>

Mocking instance and class methods

 person_mock.bar
    => ArgumentError: wrong number of arguments (0 for 1..2)

 person_mock.bar('baz')
    => RuntimeError: #bar is not Implemented for Class: PersonMock


 person_mock.mock_instance_method(:bar) do  |name, type=nil|
    "Now implemented with #{name} and #{type}"
 end

 person_mock.new.bar('foo', 'type')
    => "Now implemented with foo and type"

 person_mock.mock_class_method(:baz) do
   "Now implemented"
 end

When the model changes, the mock fails

#app/models/person.rb

class Person < ActiveRecord::Base
  belongs_to :account

  def bar(name)
    puts name
  end

end

person_mock.new.bar('foo', 'type')
  => ArgumentError: wrong number of arguments (2 for 1)


app/models/person.rb

class Person < ActiveRecord::Base
  belongs_to :account

  def foo(name, type=nil)
    puts name
  end

end

person_mock.mock_instance_method(:bar) do  |name, type=nil|
  "Now implemented with #{name} and #{type}"
end
  => NameError: undefined method `bar' for class `PersonMock'

ActiveRecord supported methods

Class methods

• create/new
• column_names
• find
• find_by
• find_by!
• find_or_create_by
• find_or_initialize_by
• where - (only supports hash input)
• delete_all/destroy_all
• all
• count
• first/last

Instance methods

• attributes
  • update
  • save
  • write_attribute - (private)
  • read_attribute - (private)

Collection Associations

• last/first
• sum(attribute)
• <<
• Enumerable methods

Known Limitations

• ::mock model names and table names must follow the default ActiveRecord naming pattern.
• Included/extended module methods will not be included on the mock.

Inspiration

Thanks to Jeff Olfert for being my original inspiration for this project.

Contributing

1. Fork it ( http://github.com/zeisler/active_mocker/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request