hash_dealer

A library for creating reusable, extendable Hash-like objects for testing

Defining HashDealers

Everyone has a favorite Hash Dealer - here is how you create your template. Note that any method can be used in your definition

HashDealer.define(:variable) do
  a("test_a")
  b("test_b")
end

Once you have your HashDealer - ask him to roll one up for you

HashDealer.roll(:variable) => {:a => "test_a", :b => "test_b"}

If you’d like to customize your Hash - just pass in some options

HashDealer.roll(:variable, :a => "My own Kief") => {:a => "My own Kief", :b => "test_b"}

Dynamic Hashes

Sometimes you’d like dynamic values for your Hash - or to use another HashDealer that you want to be dynamic - to do so, use a block inside your HashDealer definition

HashDealer.define(:dynamic) do
  abc {Kernel.rand(100)}
end

HashDealer.roll(:dynamic) => {:abc => 12}
HashDealer.roll(:dynamic) => {:abc => 32}

Nested Hashes

HashDealer does not evaluate your defined Hashes until they are called - so you can use other HashDealers that are not yet loaded in your HashDealer definitions

HashDealer.define(:b) do
  hash_a(HashDealer.roll(:a))
end

HashDealer.define(:a) do
  a("123")
end

HashDealer.roll(:b) => {:hash_a => {:a => "123"}}

Inheritance

HashDealers can inherit from one another using the :parent option in their definitions

HashDealer.define(:variable_2, :parent => :variable) do
  a("variable_2")
  my_var("abc")
end

HashDealer.roll(:variable_2) => {:a => "variable_2", :b => "test_b", :my_var => "abc"}

Elements other than Hashes

Sometimes you need to ask your dealer for something other than Hash - just define a root element

HashDealer.define(:crack) do
  root([1,2,3])
end

HashDealer.roll(:crack) => [1,2,3]

Rspec Matchers

One goal of HashDealer is to allow you to define dynamic matchers to ensure that JSON responses from interfacing APIs follow a consistent format

E.g.

response = {:id => 1, :name => "My Name", :email => "[email protected]"}
{:id => 1, :name => ":name", :email => ":email"}.matcher.should match_response(response)

We don’t care about the actual content of the fields, just that they are of the same type (generally) and that the hashes have the same fields

Similarly

response = [{:id => 1, :name => "My Name", :email => "[email protected]"}, {:id => 2, :name => "Another Developer", :email => "[email protected]"}]
[{:id => 1, :name => ":name", :email => ":email"}].matcher.should match_response(response)

We don’t care how many elements there are in the array (we might get back 100 records from our test), just that they have the correct format

The matcher method

To achieve this, we use the .matcher method, which is defined on a Hash, String, Numeric and Array and should match_response(x) as an Rspec Matcher

Contributing to hash_dealer

  • Check out the latest master to make sure the feature hasn’t been implemented or the bug hasn’t been fixed yet

  • Check out the issue tracker to make sure someone already hasn’t requested it and/or contributed it

  • Fork the project

  • Start a feature/bugfix branch

  • Commit and push until you are happy with your contribution

  • Make sure to add tests for it. This is important so I don’t break it in a future version unintentionally.

  • Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright © 2011 Lifebooker, Inc. See LICENSE.txt for further details.