Ruby unit testing is pretty standard in in the field when creating complex Ruby scripts. This help document is a simple example for how to set up unit tests on Ruby projects.

We use the base Ruby Unit testing functionality, which you can read more about here.

For our example, we will use a Queue class from RosettaCode:

require 'forwardable'
# A FIFO queue contains elements in first-in, first-out order.
# FIFO#push adds new elements to the end of the queue;
# FIFO#pop or FIFO#shift removes elements from the front.
class FIFO
  extend Forwardable
  # Creates a FIFO containing _objects_.
  def self.[](*objects)
  # Creates an empty FIFO.
  def initialize; @ary = []; end
  # Appends _objects_ to the end of this FIFO. Returns self.
  def push(*objects)
  alias << push
  alias enqueue push
  # :method: pop
  # :call-seq:
  #   pop -> obj or nil
  #   pop(n) -> ary
  # Removes an element from the front of this FIFO, and returns it.
  # Returns nil if the FIFO is empty.
  # If passing a number _n_, removes the first _n_ elements, and returns
  # an Array of them. If this FIFO contains fewer than _n_ elements,
  # returns them all. If this FIFO is empty, returns an empty Array.
  def_delegator :@ary, :shift, :pop
  alias shift pop
  alias dequeue shift
  # :method: empty?
  # Returns true if this FIFO contains no elements.
  def_delegator :@ary, :empty?
  # :method: size
  # Returns the number of elements in this FIFO.
  def_delegator :@ary, :size
  alias length size
  # Converts this FIFO to a String.
  def to_s
  alias inspect to_s

With this as our perfect code (fifo.rb), we can now create a Mimir Classroom project and start creating test cases.

Testing Constructor and empty?:

f =
assert f.empty?

Testing #push and #pop:

f =
x = f.pop
assert x == 1

Testing #size:

f =
assert f.size == 5

So on and so forth. In the code section of a unit test, you can write any Ruby code. Make sure that you make at least 1 assert or assert related function - that is how we calculate grades for this test case type.

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