README

Path: README
Last Update: Sun Jul 06 18:11:42 +0200 2008

Bacon — 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.

Whirl-wind tour

    require '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

      # 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:

    $ bacon 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 be a palindrome
    - should have super powers [FAILED]

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

    6 specifications (9 requirements), 1 failures, 0 errors

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

    $ bacon -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

    6 tests, 9 assertions, 1 failures, 0 errors

It also supports TAP:

    $ bacon -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
    not ok 6    - should have super powers: FAILED
    # Bacon::Error: no super powers found
    #   ./whirlwind.rb:39: A new array - should have super powers
    #   ./whirlwind.rb:38
    #   ./whirlwind.rb:3
    1..6
    # 6 tests, 9 assertions, 1 failures, 0 errors

    $ bacon -p whirlwind.rb | taptap -q
    Tests took 0.00 seconds.
    FAILED tests 6
       6) should have super powers: FAILED

    Failed 1/6 tests, 83.33% okay.

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

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.

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.

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
  -o, --output FORMAT      do FORMAT (SpecDox/TestUnit/Tap) output
  -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

If you don‘t want to use the standalone runner, run Bacon.summary_on_exit to install an exit handler showing the summary.

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

Bacon with autotest

Since version 1.0, there is autotest support. You need to tag your test directories (test/ or spec/) by creating an .bacon file there. Autotest then will find it. bin/bacon needs to be in PATH or RUBYPATH.

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
  • 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.

Contact

Please mail bugs, suggestions and patches to <chneukirchen@gmail.com>.

Darcs repository ("darcs send" is welcome for patches): chneukirchen.org/repos/bacon

Copying

Copyright (C) 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.

Links

Behavior-Driven Development:<behaviour-driven.org/>
RSpec:<rspec.rubyforge.org/>
test/spec:<test-spec.rubyforge.org/>
Christian Neukirchen:<chneukirchen.org/>

[Validate]