A simple and clean mock object framework.

---

Minimal (mostly drop-in) replacement for test-unit.

minitest/*

• http://rubyforge.org/projects/bfts

DESCRIPTION:

minitest provides a complete suite of testing facilities supporting TDD, BDD, mocking, and benchmarking.

minitest/unit is a small and incredibly fast unit testing framework. It provides a rich set of assertions to make your tests clean and readable.

minitest/spec is a functionally complete spec engine. It hooks onto minitest/unit and seamlessly bridges test assertions over to spec expectations.

minitest/benchmark is an awesome way to assert the performance of your algorithms in a repeatable manner. Now you can assert that your newb co-worker doesn’t replace your linear algorithm with an exponential one!

minitest/mock by Steven Baker, is a beautifully tiny mock object framework.

minitest/pride shows pride in testing and adds coloring to your test output.

minitest/unit is meant to have a clean implementation for language implementors that need a minimal set of methods to bootstrap a working test suite. For example, there is no magic involved for test-case discovery.

FEATURES/PROBLEMS:

• minitest/autorun - the easy and explicit way to run all your tests.

• minitest/unit - a very fast, simple, and clean test system.

• minitest/spec - a very fast, simple, and clean spec system.

• minitest/mock - a simple and clean mock system.

• minitest/benchmark - an awesome way to assert your algorithm’s performance.

• minitest/pride - show your pride in testing!

• Incredibly small and fast runner, but no bells and whistles.

RATIONALE:

See design_rationale.rb to see how specs and tests work in minitest.

SYNOPSIS:

Given that you’d like to test the following class:

class Meme
  def i_can_has_cheezburger?
    "OHAI!"
  end

  def will_it_blend?
    "YES!"
  end
end

Unit tests

require 'minitest/autorun'

class TestMeme < MiniTest::Unit::TestCase
  def setup
    @meme = Meme.new
  end

  def test_that_kitty_can_eat
    assert_equal "OHAI!", @meme.i_can_has_cheezburger?
  end

  def test_that_it_will_not_blend
    refute_match /^no/i, @meme.will_it_blend?
  end
end

Specs

require 'minitest/autorun'

describe Meme do
  before do
    @meme = Meme.new
  end

  describe "when asked about cheeseburgers" do
    it "must respond positively" do
      @meme.i_can_has_cheezburger?.must_equal "OHAI!"
    end
  end

  describe "when asked about blending possibilities" do
    it "won't say no" do
      @meme.will_it_blend?.wont_match /^no/i
    end
  end
end

Benchmarks

Add benchmarks to your regular unit tests. If the unit tests fail, the benchmarks won’t run.

# optionally run benchmarks, good for CI-only work!
require 'minitest/benchmark' if ENV["BENCH"]

class TestMeme < MiniTest::Unit::TestCase
  # Override self.bench_range or default range is [1, 10, 100, 1_000, 10_000]
  def bench_my_algorithm
    assert_performance_linear 0.9999 do |n| # n is a range value
      n.times do
        @obj.my_algorithm
      end
    end
  end
end

Or add them to your specs. If you make benchmarks optional, you’ll need to wrap your benchmarks in a conditional since the methods won’t be defined.

describe Meme do
  if ENV["BENCH"] then
    bench_performance_linear "my_algorithm", 0.9999 do |n|
      100.times do
        @obj.my_algorithm(n)
      end
    end
  end
end

outputs something like:

# Running benchmarks:

TestBlah    100     1000    10000
bench_my_algorithm   0.006167        0.079279        0.786993
bench_other_algorithm        0.061679        0.792797        7.869932

Output is tab-delimited to make it easy to paste into a spreadsheet.

Mocks

class MemeAsker
  def initialize(meme)
    @meme = meme
  end

  def ask(question)
    method = question.tr(" ","_") + "?"
    @meme.send(method)
  end
end

require 'minitest/autorun'

describe MemeAsker do
  before do
    @meme = MiniTest::Mock.new
    @meme_asker = MemeAsker.new @meme
  end

  describe "#ask" do
    describe "when passed an unpunctuated question" do
      it "should invoke the appropriate predicate method on the meme" do
        @meme.expect :will_it_blend?, :return_value
        @meme_asker.ask "will it blend"
        @meme.verify
      end
    end
  end
end

Customizable Test Runner Types:

MiniTest::Unit.runner=(runner) provides an easy way of creating custom test runners for specialized needs. Justin Weiss provides the following real-world example to create an alternative to regular fixture loading:

class MiniTestWithHooks::Unit < MiniTest::Unit
  def before_suites
  end

  def after_suites
  end

  def _run_suites(suites, type)
    begin
      before_suites
      super(suites, type)
    ensure
      after_suites
    end
  end

  def _run_suite(suite, type)
    begin
      suite.before_suite
      super(suite, type)
    ensure
      suite.after_suite
    end
  end
end

module MiniTestWithTransactions
  class Unit < MiniTestWithHooks::Unit
    include TestSetupHelper

    def before_suites
      super
      setup_nested_transactions
      # load any data we want available for all tests
    end

    def after_suites
      teardown_nested_transactions
      super
    end
  end
end

MiniTest::Unit.runner = MiniTestWithTransactions::Unit.new

REQUIREMENTS:

• Ruby 1.8, maybe even 1.6 or lower. No magic is involved.

INSTALL:

sudo gem install minitest

On 1.9, you already have it. To get newer candy you can still install the gem, but you’ll need to activate the gem explicitly to use it:

require 'rubygems'
gem 'minitest' # ensures you're using the gem, and not the built in MT
require 'minitest/autorun'

# ... usual testing stuffs ...

LICENSE:

(The MIT License)

Copyright © Ryan Davis, Seattle.rb

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the ‘Software’), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED ‘AS IS’, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

lib/minitest/mock.rb
lib/minitest/unit.rb