/rspec-cookie

Primary LanguageRuby

RSpec Drill: Test a Cookie

Writing good object-oriented tests is not always easy. A good test relies not only on the fact that the code is well-written, but that the test itself is well-written.

When you write examples (tests in RSpec are called examples), you should be consuming the public interface of your code.

What does this mean? In the simplest explanation, it means that your examples should test the inputs and outputs of the publicly defined methods for a given class. Internal variables and methods marked private or protected are off-limits. Your tests need to follow the same OOP rules as your objects.

In this challenge, you will be working with a feature-complete program. However, much of the application code is commented out and most of the specs are still pending.

Your task is to implement all of the pending specs. You will need to utilize the RSpec API including:

RSpec is designed to read very fluidly, but don't be fooled by the syntactic sugar it provides. It is still just Ruby. A statement like

apple.price.should eq 0.99

is the same as

apple.price.should( eq(2.00) )

without the parentheses.

Objectives

Grab the files from the gist

Download the cookie.rb and cookie_spec.rb files from the gist.

Orient yourself

Before you even begin figuring out how to write your specs, look at the existing specs. Take note of the structure and look at how the pieces fit together.

Then run the specs with

$ rspec cookie_spec.rb --format documentation --color

and study the output.

After you have oriented yourself, you should be able to provide at least an educated guess when answering the following questions:

  • What does a describe block do?
  • What does a context block do?
  • How are describe blocks used differently from context blocks?
  • What are the arguments for the it method?
  • What does the let method do?
  • How is expect used differently from should?

You don't need to know all of the answers now, but you should be able to generate a rough idea of how the syntax works from the provided code.

Take note of the structure of the specs. There are some real patterns at work here:

  • A describe block for each public method of the class, using # to indicate an instance method.
  • Use of let to define objects which will be used throughout the specs.
  • Use of the context block to identify different environments and states
  • Descriptions are written to form complete sentences which read as clear specifications or expectations, example:
Cookie
  #status
    when unbaked
      is `:doughy`

Write the pending examples

You will notice that most of the specs in cookie_spec.rb are pending, i.e. they have a description but are not actually testing anything.

Your task is implement each of the pending specs one at a time, make sure that they fail, and then uncomment the minimum amount of code possible to make them pass.

This is an important cycle to get used to:

  1. Write a spec
  2. Ensure that the spec fails when the relevant code is missing (or commented out)
  3. Ensure that the spec passes when the relevant code is implemenented

Use this cycle to fill out all of the pending examples in cookie_spec.rb.