Notes posted by emime

Input strings are treated as regexp

Input strings are treated as regexp, but you can escape special regexp characters as usual:

"*test*".should match "\\*test\\*" #=> pass
"*test*".should match '\*test\*' #=> pass
"*test*".should match /\*test\*/ #=> pass

Remove non empty directories

To remove a non empty directory use FileUtils:

Dir.mkdir("test_dir")
Dir.mkdir("test_dir/sub_dir")
FileUtils.remove_dir("test_dir",true)

Careful when comparing strings

Input String is treated as Regexp:

"*test*".should match "*test*" #=> fail
"*test*".should match ".*test.*" #=> pass

Regexp special characters inside input String can’t [be] escaped:

"*test*".should match "\*test\*" #=> fail
"*test*".should match /\*test*\/ #=> pass

Eql equals ==

Use eql to compare values as you would use ==:

"test".should eql "test" #=> pass
"test".should == "test" #=> pass

Do not confuse with equal which compares objects.

Test strings with eql

Equal fails when comparing two different string objects:

"test".should equal "test" #=> fail
"test".should match "test" #=> pass
"test".should eql "test" #=> pass

In fact:

"test".object_id.should_not eql "test".object_id #=> pass

Match fails when the string contains regex special characters not escaped:

"*test*".should match "*test*" #=> fail for invalid regex
"*test*".should eql "*test*" #=> pass

In fact, match treats input as regexp:

"*test*".should match /\*test\*/ #=> pass

Get all inner texts

Extend REXML::Element so that it can get the first text and following inner texts (child texts included) of the current element as array and as string:

class REXML::Element

 def inner_texts
  REXML::XPath.match(self,'.//text()')
 end

 def inner_text
  REXML::XPath.match(self,'.//text()').join 
 end

end

Reusing shared examples

share_examples_for “a shape” do

   it "should have a color" do
     @shape.color.should == :black
   end
 end

describe "a circle" do
  before(:all) do
    @shape = Circle.new
  end 
  it_should_behave_like "a shape"
end

A stub with argument and return value

it “should use a dummy method with argument and return value” do

 dummy = mock("dummy").stub!(:emulate)
 dummy.should_receive(:emulate).with(:something).and_return("Done! sir!")
 dummy.emulate(:something).should == "Done! sir!"
end

Input for trigonometric functions must be radians

You must use radians to have the right result. For example to compute the sin of 125 degrees use:

Math.sin(125*Math::PI/180)