Why am I getting a "wrong number of arguments (0 for 2)" exception in my Ruby Code?

Question

I'm trying to polish up my Ruby by re writing Kent Beck's xUnit Python example from "Test Driven Development: By Example". I've got quite far but now I get the following error when I run which I don't grok.

C:\Documents and Settings\aharmel\My Documents\My Workspace\TDD_Book\TDDBook_xUnit_RubyVersion\lib\main.rb:21:in `test_running': wrong number of arguments (0 for 2) (ArgumentError)
    from C:\Documents and Settings\aharmel\My Documents\My Workspace\TDD_Book\TDDBook_xUnit_RubyVersion\lib\main.rb:21:in `run'
    from C:\Documents and Settings\aharmel\My Documents\My Workspace\TDD_Book\TDDBook_xUnit_RubyVersion\lib\main.rb:85

My code looks like this:

class TestCase
  def initialize(name)
    puts "1.  inside TestCase.initialise: @name: #{name}"
    @name = name
  end
  def set_up
    # No implementation (but present to be overridden in WasRun) 
  end
  def run
    self.set_up
    self.send @name  # <<<<<<<<<<<<<<<<<<<<<<<<<= ERROR HERE!!!!!!
  end
end

class WasRun < TestCase
  attr_accessor :wasRun
  attr_accessor :wasSetUp 

  def initialize(name)
    super(name)
  end
  def set_up
    @wasRun = false
    @wasSetUp = true
  end
  def test_method
    @wasRun = true
  end
end

class TestCaseTest < TestCase
  def set_up
    @test = WasRun.new("test_method")
  end
  def test_running
    @test.run
    puts "test was run? (true expected): #{test.wasRun}"
  end
  def test_set_up
    @test.run
    puts "test was set up? (true expected): #{test.wasSetUp}"
  end
end

TestCaseTest.new("test_running").run

Can anyone point out my obvious mistake?

Answer 1

One thing that leaps out is that the send method expects a symbol identifying the method name, but you're trying to use an instance variable.

Object.send documentation

Also, shouldn't lines like this:

puts "test was run? (true expected): #{test.wasRun}"

be:

puts "test was run? (true expected): #{@test.wasRun}"

?

Answer 2

It's your print statement:

  puts "test was run? (true expected): #{test.wasRun}"

should be

  puts "test was run? (true expected): #{@test.wasRun}"

without the '@' you are calling Kernel#test, which expects 2 variables.