From: Massimiliano Mirra <list@...>
Date: 2001-10-22T06:36:33+09:00
Subject: [ruby-talk:22902] First steps in unit testing

I'm using rubyunit and it is my first experience with unit testing in
general.  I'd like to hear some opinions on a simple style matter.

Let's say this class is being tested:

class Point
  def initialize(x=0, y=0)
    @x,@y=x,y
    self
  end

  def move(by_x, by_y)
    @x += by_x
    @y += by_y
    self
  end

  attr_reader :x,:y
end

I've seen three styles of writing the class that does the testing:

1)

class TestPoint < RUNIT::TestCase
  def setup
    @p = Point.new
  end

  def setupMoved
    @p.move(10,6)
  end
  attach_setup :setupMoved, :testMoved

  def testMoved
    assert_equal( @p.x, 10 )
    assert_equal( @p.y, 6 )
  end
end

2)

class TestPoint < RUNIT::TestCase
  def testMoved
    point = movedPoint
    assert_equal( @p.x, 10 )
    assert_equal( @p.y, 6 )
  end

  def movedPoint
    Point.new.move(10, 6)
  end
end

3)

class TestPoint < RUNIT::TestCase
  def testMoved
    point = Point.new.move(10,6)
    assert_equal( @p.x, 10 )
    assert_equal( @p.y, 6 )
  end
end
    

In other words, 1) uses specific setups, 2) too but with factory
methods, and 3) does it all in the testing method.

Aside from the readability in example 3), that however could go down
as the test goes up in setup requirements, are there significant
advantages to one way over the others?

Massimiliano