parse.rb

gistfile1.rb

def parse(name)
  pattern = /
    (?:\[(\w+)\])?
    (\w+)
    (?:\[(\w+)\])?
  /x
  words = pattern.match(name).captures
  combinations = [words[1]]
  if words[0]
    combinations << words[0] + words[1]
  end
  if words[2]
    combinations << words[1] + words[2]
  end
  if words[0] and words[2]
    combinations << words[0] + words[1] + words[2]
  end
  combinations
end

describe "parse" do

  it "should list all permutations, text in brackets is optional" do
    strings = parse("foo[bar]")
    strings.should include('foo')
    strings.should include('foobar')
    strings.should_not include('bar')
    strings.size.should == 2
  end

  it "should list all permutations, text in brackets is optional" do
    strings = parse("[foo]bar")
    strings.should include('bar')
    strings.should include('foobar')
    strings.should_not include('foo')
    strings.size.should == 2
  end
 
  it "should list all permutations, text in brackets is optional" do
    strings = parse("[foo]bar[baz]")
    strings.should include('foobar')
    strings.should include('bar')
    strings.should include('barbaz')
    strings.should include('foobarbaz')
    strings.should_not include('foo')
    strings.should_not include('baz')
    strings.size.should == 4
  end

  it "should return the string, when there are no brackets" do
    strings = parse("foo")
    strings.should include('foo')
    strings.size.should == 1
  end

end