MacBacon – small RSpec clone.

"Truth will sooner come out from error than from confusion."
                                            ---Francis Bacon

Bacon is a small RSpec clone weighing less than 350 LoC but nevertheless providing all essential features.

This MacBacon fork is created and maintained by Eloy Durán (@alloy). It differs with regular Bacon in that it operates properly in a NSRunloop based environment. I.e. MacRuby/Objective-C. See the paragraph about the ‘wait` command for more info.

Whirl-wind tour

require 'mac_bacon'

describe 'A new array' do
  before do
    @ary = Array.new
  end

  it 'should be empty' do
    @ary.should.be.empty
    @ary.should.not.include 1
  end

  it 'should have zero size' do
    @ary.size.should.equal 0
    @ary.size.should.be.close 0.1, 0.5
  end

  it 'should raise on trying fetch any index' do
    lambda { @ary.fetch 0 }.
      should.raise(IndexError).
      message.should.match(/out of array/)

    # Alternatively:
    should.raise(IndexError) { @ary.fetch 0 }
  end

  it 'should have an object identity' do
    @ary.should.not.be.same_as Array.new
  end

  it 'should perform a long running operation' do
    @ary.performSelector("addObject:", withObject:"soup", afterDelay:0.5)
    wait 0.6 do
      @ary.size.should.be 1
    end
  end

  # Custom assertions are trivial to do, they are lambdas returning a
  # boolean vale:
  palindrome = lambda { |obj| obj == obj.reverse }
  it 'should be a palindrome' do
    @ary.should.be.a palindrome
  end

  it 'should have super powers' do
    should.flunk "no super powers found"
  end
end

Now run it:

$ macbacon whirlwind.rb
A new array
  - should be empty
  - should have zero size
  - should raise on trying fetch any index
  - should have an object identity
  - should perform a long running operation
  - should be a palindrome
  - should have super powers [MISSING]

Bacon::Error: no super powers found
	./whirlwind.rb:44:in `block': A new array - should have super powers

Bacon::Error: empty specification: A new array should have super powers

7 specifications (10 requirements), 1 failures, 0 errors

If you want shorter output, use the Test::Unit format:

$ macbacon -q whirlwind.rb
......F
Bacon::Error: no super powers found
	./whirlwind.rb:39: A new array - should have super powers
	./whirlwind.rb:38
	./whirlwind.rb:3

7 tests, 10 assertions, 1 failures, 0 errors

It also supports TAP:

$ macbacon -p whirlwind.rb
ok 1        - should be empty
ok 2        - should have zero size
ok 3        - should raise on trying fetch any index
ok 4        - should have an object identity
ok 5        - should be a palindrome
ok 6        - should perform a long running operation
not ok 7    - should have super powers: FAILED
# Bacon::Error: no super powers found
# 	./whirlwind.rb:44: A new array - should have super powers
1..7
# 7 tests, 10 assertions, 1 failures, 0 errors

$ macbacon -p whirlwind.rb | taptap -q
Tests took 0.00 seconds.
FAILED tests 7
   7) should have super powers: FAILED

Failed 1/7 tests, 83.33% okay.

(taptap is available from chneukirchen.org/repos/taptap/)

As of Bacon 1.1, it also supports Knock:

$ macbacon -k whirlwind.rb
ok - should be empty
ok - should have zero size
ok - should raise on trying fetch any index
ok - should have an object identity
ok - should be a palindrome
ok - should perform a long running operation
not ok - should have super powers: FAILED
# Bacon::Error: no super powers found
# 	./whirlwind.rb:4: A new array - should have super powers

$ bacon -k whirlwind.rb | kn-sum
7 tests, 1 failed (83.3333% succeeded)

(knock is available from github.com/chneukirchen/knock/)

Implemented assertions

  • should.<predicate> and should.be.<predicate>

  • should.equal

  • should.match

  • should.be.identical_to / should.be.same_as

  • should.raise(*exceptions) { }

  • should.change { }

  • should.throw(symbol) { }

  • should.satisfy { |object| }

Added core predicates

  • Object#true?

  • Object#false?

  • Proc#change?

  • Proc#raise?

  • Proc#throw?

  • Numeric#close?

before/after

before and after need to be defined before the first specification in a context and are run before and after each specification.

As of Bacon 1.1, before and after do nest in nested contexts.

Shared contexts

You can define shared contexts in Bacon like this:

shared "an empty container" do
  it "should have size zero" do
  end

  it "should be empty" do
  end
end

context "A new array" do
  behaves_like "an empty container"
end

These contexts are not executed on their own, but can be included with behaves_like in other contexts. You can use shared contexts to structure suites with many recurring specifications.

Matchers

Custom matchers are simply lambdas returning a boolean value, for example:

def shorter_than(max_size)
  lambda { |obj| obj.size < max_size }
end

[1,2,3].should.be shorter_than(5)

You can use modules and extend to group matchers for use in multiple contexts.

wait

Often in Objective-C apps, code will not execute immediately, but scheduled on a runloop for later execution. Therefor a mechanism is needed that will postpone execution of some assertions for a period of time. This is where the ‘wait` macro comes in:

it 'should perform a long running operation' do
  # Here a method call is scheduled to be performed ~0.5 seconds in the future
  @ary.performSelector("addObject:", withObject:"soup", afterDelay:0.5)
  wait 0.6 do
    # This block is executed ~0.6 seconds in the future
    @ary.size.should.be 1
  end
end

The postponed block does not halt the thread, but is scheduled on the runloop as well. This means that your runloop based code will have a chance to perform its job before the assertions in the block are executed.

You can schedule as many blocks as you’d want and even nest them.

bacon standalone runner

-s, --specdox            do AgileDox-like output (default)
-q, --quiet              do Test::Unit-like non-verbose output
-p, --tap                do TAP (Test Anything Protocol) output
-k, --knock              do Knock output
-o, --output FORMAT      do FORMAT (SpecDox/TestUnit/Tap) output
-Q, --no-backtrace       don't print backtraces  
-a, --automatic          gather tests from ./test/, include ./lib/
-n, --name NAME          runs tests matching regexp NAME
-t, --testcase TESTCASE  runs tests in TestCases matching regexp TESTCASE

Object#should

You can use Object#should outside of contexts, where the result of assertion will be returned as a boolean. This is nice for demonstrations, quick checks and doctest tests.

>> require 'mac_bacon'
>> (1 + 1).should.equal 2
=> true
>> (6*9).should.equal 42
=> false

Converting specs

spec-converter is a simple tool to convert test-unit or dust style tests to test/spec specs.

It can be found at opensource.thinkrelevance.com/wiki/spec_converter.

Thanks to

  • Michael Fellinger, for fixing Bacon for 1.9 and various improvements.

  • Gabriele Renzi, for implementing Context#should.

  • James Tucker, for the autotest support.

  • Yossef Mendelssohn, for nested contexts.

  • everyone contributing bug fixes.

History

  • January 7, 2008: First public release 0.9.

  • July 6th, 2008: Second public release 1.0.

    • Add Context#should as a shortcut for Context#it(‘should ’ + _).

    • describe now supports multiple arguments for better organization.

    • Empty specifications are now erroneous.

    • after-blocks run in the case of exceptions too.

    • Autotest support.

    • Bug fixes.

  • November 30th, 2008: Third public release 1.1.

    • Nested before/after.

    • Add -Q/–no-backtraces to not show details about failed specifications.

    • Add Knock output.

    • Bug fixes.

  • January 10th, 2011: MacBacon fork release 1.1

    • Make it work in a NSRunloop environment

    • Add ‘wait’

    • Remove extras, for now

Contact

Please mail bugs, suggestions and patches for Bacon to <[email protected]>

Git repository (patches rebased on HEAD are most welcome): github.com/chneukirchen/bacon git://github.com/chneukirchen/bacon.git

For MacBacon contact <[email protected]>

And repository location: github.com/alloy/MacBacon git://github.com/alloy/MacBacon.git

Copying

Copyright © 2007, 2008 Christian Neukirchen <purl.org/net/chneukirchen>

Bacon is freely distributable under the terms of an MIT-style license. See COPYING or www.opensource.org/licenses/mit-license.php.

Behavior-Driven Development

<behaviour-driven.org/>

RSpec

<rspec.rubyforge.org/>

test/spec

<test-spec.rubyforge.org/>

Christian Neukirchen

<chneukirchen.org/>