Module: Minitest

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

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

==== 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

Define your tests as methods beginning with test_.

require "minitest/autorun"

class TestMeme < Minitest::Test
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 tests.

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

class TestMeme < Minitest::Benchmark
# 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. In minitest 5, the describe name needs to match
/Bench(mark)?$/.

describe "Meme Benchmark" 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

===== Running Your Tests

Ideally, you'll use a rake task to run your tests, either piecemeal or
all at once. Both rake and rails ship with rake tasks for running your
tests. BUT! You don't have to:

% ruby -Ilib:test test/minitest/test_minitest_unit.rb
Run options: --seed 37685

# Running:

...................................................................... (etc)

Finished in 0.107130s, 1446.8403 runs/s, 2959.0217 assertions/s.

155 runs, 317 assertions, 0 failures, 0 errors, 0 skips

There are runtime options available, both from minitest itself, and also
provided via plugins. To see them, simply run with --help:

% ruby -Ilib:test test/minitest/test_minitest_unit.rb --help
minitest options:
-h, --help Display this help.
-s, --seed SEED Sets random seed
-v, --verbose Verbose. Show progress processing files.
-n, --name PATTERN Filter run on /pattern/ or string.

Known extensions: pride, autotest
-p, --pride Pride. Show your testing pride!
-a, --autotest Connect to autotest server.

==== Writing Extensions

To define a plugin, add a file named minitest/XXX_plugin.rb to your
project/gem. Minitest will find and require that file using
Gem.find_files. It will then try to call plugin_XXX_init during
startup. The option processor will also try to call plugin_XXX_options
passing the OptionParser instance and the current options hash. This
lets you register your own command-line options. Here's a totally
bogus example:

# minitest/bogus_plugin.rb:

module Minitest
def self.plugin_bogus_options(opts, options)
opts.on "--myci", "Report results to my CI" do
options[:myci] = true
options[:myci_addr] = get_myci_addr
options[:myci_port] = get_myci_port
end
end

def self.plugin_bogus_init(options)
self.reporter << MyCI.new(options) if options[:myci]
end
end

===== Adding custom reporters

Minitest uses composite reporter to output test results using multiple
reporter instances. You can add new reporters to the composite during
the init_plugins phase. As we saw in plugin_bonus_init above, you
simply add your reporter instance to the composite via <<.

AbstractReporter defines the API for reporters. You may subclass it
and override any method you want to achieve your desired behavior.

start :: Called when the run has started.
record :: Called for each result, passed or otherwise.
report :: Called at the end of the run.
passed? :: Called to see if you detected any problems.

Using our example above, here is how we might implement MyCI:

# minitest/bogus_plugin.rb

module Minitest
class MyCI < AbstractReporter
attr_accessor :results, :addr, :port

def initialize options
self.results = []
self.addr = options[:myci_addr]
self.port = options[:myci_port]
end

def record result
self.results << result
end

def report
CI.connect(addr, port).send_results self.results
end
end
end

==== 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 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

===== How to share code across test classes?

Use a module. That's exactly what they're for:

module UsefulStuff
def useful_method
# ...
end
end

describe Blah do
include UsefulStuff

def test_whatever
# useful_method available here
end
end

Remember, describe simply creates test classes. It's just ruby at
the end of the day and all your normal Good Ruby Rules (tm) apply. If
you want to extend your test using setup/teardown via a module, just
make sure you ALWAYS call super. before/after automatically call super
for you, so make sure you don't do it twice.

==== Prominent Projects using Minitest:

* arel
* journey
* mime-types
* nokogiri
* rails (active_support et al)
* rake
* rdoc
* ...and of course, everything from seattle.rb...

==== 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-bang :: Adds support for RSpec-style let! to immediately
invoke let statements before each test.
minitest-bisect :: Helps you isolate and debug random test failures.
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-documentation :: Minimal documentation format inspired by rspec's.
minitest-doc_reporter :: Detailed output inspired by rspec's documentation
format.
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-filesystem :: Adds assertion and expectation to help testing
filesystem contents.
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-line :: Run test at line number.
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-parallel-db :: Run tests in parallel with a single database.
minitest-power_assert :: PowerAssert for Minitest.
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-rg :: Colored red/green output for Minitest.
minitest-rspec_mocks :: Use RSpec Mocks with Minitest.
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-expect :: Expect syntax for Spec (e.g.
expect(sequences).to_include :celery_man).
minitest-spec-magic :: Spec extensions for Rails and beyond.
minitest-spec-rails :: Drop in Spec superclass for
ActiveSupport::TestCase.
minitest-stately :: Find leaking state between tests
minitest-stub_any_instance :: Stub any instance of a method on the given class
for the duration of a block.
minitest-stub-const :: Stub constants for the duration of a block.
minitest-tags :: Add tags for minitest.
minitest-vcr :: Automatic cassette managment with Spec
and VCR.
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 :: 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.
rspec2minitest :: Easily translate any RSpec matchers to Minitest
assertions and expectations.

==== 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 1.8.7+. No magic is involved. I hope.

==== INSTALL:

sudo gem install minitest

On 1.9, you already have it. To get newer candy you can still install
the gem, and then requiring "minitest/autorun" should automatically
pull it in. If not, you'll need to do it yourself:

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.