ruby/test/lib/minitest

= minitest/{unit,spec,mock,benchmark}

home :: https://github.com/seattlerb/minitest
rdoc :: http://docs.seattlerb.org/minitest
vim  :: https://github.com/sunaku/vim-ruby-minitest

== DESCRIPTION:

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

    "I had a class with Jim Weirich on testing last week and we were
     allowed to choose our testing frameworks. Kirk Haines and I were
     paired up and we cracked open the code for a few test
     frameworks...

     I MUST say that minitest is *very* readable / understandable
     compared to the 'other two' options we looked at. Nicely done and
     thank you for helping us keep our mental sanity."

    -- Wayne E. Seguin

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 (and stub)
object framework.

minitest/pride shows pride in testing and adds coloring to your test
output. I guess it is an example of how to write IO pipes too. :P

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.

    "Again, I can't praise enough the idea of a testing/specing
     framework that I can actually read in full in one sitting!"

    -- Piotr Szotkowski

Comparing to rspec:

    rspec is a testing DSL. minitest is ruby.

    -- Adam Hawkins, "Bow Before MiniTest"

minitest doesn't reinvent anything that ruby already provides, like:
classes, modules, inheritance, methods. This means you only have to
learn ruby to use minitest and all of your regular OO practices like
extract-method refactorings still apply.

== 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/stub 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

    def test_that_will_be_skipped
      skip "test this later"
    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

For matchers support check out:

https://github.com/zenspider/minitest-matchers

=== 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
        @obj.my_algorithm(n)
      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

=== Stubs

  def test_stale_eh
    obj_under_test = Something.new

    refute obj_under_test.stale?

    Time.stub :now, Time.at(0) do   # stub goes away once the block is done
      assert obj_under_test.stale?
    end
  end

A note on stubbing: In order to stub a method, the method must
actually exist prior to stubbing. Use a singleton method to create a
new non-existing method:

  def obj_under_test.fake_method
    ...
  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

== FAQ

=== How to test SimpleDelegates?

The following implementation and test:

    class Worker < SimpleDelegator
      def work
      end
    end

    describe Worker do
      before do
        @worker = Worker.new(Object.new)
      end

      it "must respond to work" do
        @worker.must_respond_to :work
      end
    end

outputs a failure:

      1) Failure:
    Worker#test_0001_must respond to work [bug11.rb:16]:
    Expected #<Object:0x007f9e7184f0a0> (Object) to respond to #work.

Worker is a SimpleDelegate which in 1.9+ is a subclass of BasicObject.
Expectations are put on Object (one level down) so the Worker
(SimpleDelegate) hits `method_missing` and delegates down to the
`Object.new` instance. That object doesn't respond to work so the test
fails.

You can bypass `SimpleDelegate#method_missing` by extending the worker
with `MiniTest::Expectations`. You can either do that in your setup at
the instance level, like:

    before do
      @worker = Worker.new(Object.new)
      @worker.extend MiniTest::Expectations
    end

or you can extend the Worker class (within the test file!), like:

    class Worker
      include ::MiniTest::Expectations
    end

== Known Extensions:

capybara_minitest_spec      :: Bridge between Capybara RSpec matchers and MiniTest::Spec expectations (e.g. page.must_have_content('Title')).
minispec-metadata           :: Metadata for describe/it blocks
                               (e.g. `it 'requires JS driver', js: true do`)
minitest-ansi               :: Colorize minitest output with ANSI colors.
minitest-around             :: Around block for minitest. An alternative to setup/teardown dance.
minitest-capistrano         :: Assertions and expectations for testing Capistrano recipes
minitest-capybara           :: Capybara matchers support for minitest unit and spec
minitest-chef-handler       :: Run Minitest suites as Chef report handlers
minitest-ci                 :: CI reporter plugin for MiniTest.
minitest-colorize           :: Colorize MiniTest output and show failing tests instantly.
minitest-context            :: Defines contexts for code reuse in MiniTest
                               specs that share common expectations.
minitest-debugger           :: Wraps assert so failed assertions drop into
                               the ruby debugger.
minitest-display            :: Patches MiniTest to allow for an easily configurable output.
minitest-emoji              :: Print out emoji for your test passes, fails, and skips.
minitest-english            :: Semantically symmetric aliases for assertions and expectations.
minitest-excludes           :: Clean API for excluding certain tests you
                               don't want to run under certain conditions.
minitest-firemock           :: Makes your MiniTest mocks more resilient.
minitest-great_expectations :: Generally useful additions to minitest's assertions and expectations
minitest-growl              :: Test notifier for minitest via growl.
minitest-implicit-subject   :: Implicit declaration of the test subject.
minitest-instrument         :: Instrument ActiveSupport::Notifications when
                               test method is executed
minitest-instrument-db      :: Store information about speed of test
                               execution provided by minitest-instrument in database
minitest-libnotify          :: Test notifier for minitest via libnotify.
minitest-macruby            :: Provides extensions to minitest for macruby UI testing.
minitest-matchers           :: Adds support for RSpec-style matchers to minitest.
minitest-metadata           :: Annotate tests with metadata (key-value).
minitest-mongoid            :: Mongoid assertion matchers for MiniTest
minitest-must_not           :: Provides must_not as an alias for wont in MiniTest
minitest-nc                 :: Test notifier for minitest via Mountain Lion's Notification Center
minitest-predicates         :: Adds support for .predicate? methods
minitest-rails              :: MiniTest integration for Rails 3.x
minitest-rails-capybara     :: Capybara integration for MiniTest::Rails
minitest-reporters          :: Create customizable MiniTest output formats
minitest-should_syntax      :: RSpec-style +x.should == y+ assertions for MiniTest
minitest-shouldify          :: Adding all manner of shoulds to MiniTest (bad idea)
minitest-spec-context       :: Provides rspec-ish context method to MiniTest::Spec
minitest-spec-magic         :: Minitest::Spec extensions for Rails and beyond
minitest-spec-rails         :: Drop in MiniTest::Spec superclass for ActiveSupport::TestCase.
minitest-stub-const         :: Stub constants for the duration of a block
minitest-tags               :: add tags for minitest
minitest-wscolor            :: Yet another test colorizer.
minitest_owrapper           :: Get tests results as a TestResult object.
minitest_should             :: Shoulda style syntax for minitest test::unit.
minitest_tu_shim            :: minitest_tu_shim bridges between test/unit and minitest.
mongoid-minitest            :: MiniTest matchers for Mongoid.
pry-rescue                  :: A pry plugin w/ minitest support. See pry-rescue/minitest.rb.

== Unknown Extensions:

Authors... Please send me a pull request with a description of your minitest extension.

* assay-minitest
* detroit-minitest
* em-minitest-spec
* flexmock-minitest
* guard-minitest
* guard-minitest-decisiv
* minitest-activemodel
* minitest-ar-assertions
* minitest-capybara-unit
* minitest-colorer
* minitest-deluxe
* minitest-extra-assertions
* minitest-rails-shoulda
* minitest-spec
* minitest-spec-should
* minitest-sugar
* minitest_should
* mongoid-minitest
* spork-minitest

== 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 ...

DO NOTE: There is a serious problem with the way that ruby 1.9/2.0
packages their own gems. They install a gem specification file, but
don't install the gem contents in the gem path. This messes up
Gem.find_files and many other things (gem which, gem contents, etc).

Just install minitest as a gem for real and you'll be happier.

== LICENSE:

(The MIT License)

Copyright (c) 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.