Zapata

Who has time to write tests? This is a revolutional tool to make them write themselves.

Emiliano Zapata

What is your problem?

There comes a day where you have this bullshit class RobotToTest. We need tests. :shipit:

class RobotToTest
  def initialize(human_name, cv)
    @name = robot_name(human_name)
  end

  def robot_name(human_name)
    "#{self.class.prefix}_#{human_name}"
  end

  def cv
    { planets: planets }
  end

  def nested_fun_objects(fun_objects)
    'It was fun'
  end

  def self.prefix
    'Robot'
  end

  private

  def planets
    ['Mars', Human.home]
  end

  def fun_objects
    [i(array in array), { hash: nested_hash }]
  end

  def nested_hash
    { in_hash: { in: array } }
  end

  def array
    %w(array)
  end
end

# just another class to analyze
class Human
  def initialize
    human_name = 'Emiliano'
  end

  def self.home
    'Earth'
  end
end

Solving it

You run zapata generate app/models/robot_to_test.rb and pop the champagne. Zapata generated spec/models/robot_to_test_spec.rb for you.

describe RobotToTest do
  let(:robot_to_test) do
    RobotToTest.new('Emiliano', { planets: ['Mars', Human.home] })
  end

  it '#robot_name' do
    expect(robot_to_test.robot_name('Emiliano')).to eq('Robot_Emiliano')
  end

  it '#cv' do
    expect(robot_to_test.cv).to eq({ planets: ['Mars', 'Earth'] })
  end

  it '#nested_fun_objects' do
    expect(robot_to_test.nested_fun_objects([
      [:array, :in, :array],
      {
        hash: {
          in_hash: {
            in: ['array']
          }
        }
      }
    ])).to eq('It was fun')
  end

  it '#prefix' do
    expect(RobotToTest.prefix).to eq('Robot')
  end
end

What does it do?

It tries to write a passing RSpec spec off the bat. It does fancy analysis to predict the values it could feed to the API of a class.

To be more specific:

Analyzes all vars and methods definitions in app/models
Checks what arguments does a testable method in app/models/robot_to_test.rb need
Searches for such variable or method name in methods in analyzed
Selects the most probable value by how many times it was repeated in code
Runs the RSpec and fills in the expected values of the test with those returned by RSpec

For more things it can currently do check https://github.com/Nedomas/zapata/tree/master/spec

Installation

It should be as easy as

gem install zapata

gem 'zapata', groups: %w(development test)

To use run

zapata generate app/models/model_name.rb

Collaboration :heart:

I know that code analyzing is a sexy sphere to work on for many developers. So here it is - a sexy project where you can realize your wet dreams about magic in Ruby.

To install, run:

git clone https://github.com/Nedomas/zapata
cd zapata
bundle exec rake install

For specs, run: