Cucumber Example for testing a RESTful API

api.feature

Scenario: Get List of My Hitchhiking Items via API
    Given the existing things:
        |name|
        |The Guide (duh)|
        |A towel|
        |Sub-Etha Sens-O-Matic|
        |Pan Galactic Gargle Blaster|
        |Kill-o-Zap blaster pistol|
    And the existing accounts:
        |email|name|password|
        |[email protected]|Arthur Dent|Praxibetel Ix|
    And the account with email "[email protected]" has a thing named "A towel"
    And the account with email "[email protected]" has a thing named "Sub-Etha Sens-O-Matic"
    When I request the "my things" endpoint using credentials "[email protected]":"Praxibetel Ix"
    Then I should receive a json list like:
        |name|
        |A towel|
        |Sub-Etha Sens-O-Matic|
        
Scenario: Use Nutrimatic Drink Dispenser
    Given the existing accounts:
        |email|name|password|
        |[email protected]|Arthur Dent|dolphin|
    When I request the "dispense drink 'tea'" endpoint with credentials "[email protected]":"dolphin"
    Then I should receive a json hash like:
        |description|
        |a concoction 'almost, but not quite entirely unlike tea'|

endpoints.rb

def visit_endpoint(endpoint, data={}, params={})
  params[:format] ||= 'json'
  args = case endpoint
    when /^my things$/i
      visit account_things_path(params), :get
    when /^dispense drink '([^']*)'$/i
      visit account_drinks_path(params), :post, {:drink => $1}
    else raise "No endpoint mapping for '#{endpoint}'"
  end
  @response
end

json_helpers.rb

def from_json(response)
  response.should be_success
  ActiveSupport::JSON.decode(response.body)
end

def compare_json_list_to_table(json_list, table)
  json_list.should have(table.rows.size).items
  
  table.hashes.each do |table_row_hash|
    #ordering can be shaky, so need to find the right item in the json list
    pk = table.headers.first
    json_hash = json_list.detect{|jh| (jh[pk] || jh[pk.to_sym]) == table_row_hash[pk] }
    raise "JSON array did not contain a hash containing #{pk} => #{table_row_hash[pk]}.  Be sure to put your PK in the first column of the table." unless json_hash
    compare_json_hash_to_table_row_hash(json_hash, table_row_hash)
  end
end

def compare_json_hash_to_table_row_hash(json_hash, table_row_hash)
  table_row_hash.each do |key, control|
    test = json_hash[key] || json_hash[key.to_sym]
    if control == '*' # wildcard; just test that key exists, value is irrelevant or volatile
      test.to_s.should_not be_empty
    else
      test.to_s.should eql control
    end
  end
end

def visit_authenticated_endpoint(endpoint, credentials, data={}, params={})
  basic_auth(credentials[:user], credentials[:password])
  visit_endpoint(endpoint, data, params)
end

json_steps.rb

When /^I request the "([^"]*)" endpoint using credentials "([^"]*)":"([^"]*)"$/ do |endpoint, email, pwd|
  visit_authenticated_endpoint(endpoint, {:user => email, :password => pwd})
end

When /^I request the "([^"]*)" endpoint$/ do |endpoint, email, pwd|
  visit_endpoint(endpoint)
end


Then /^I should receive a json list like:$/ do |table|
  compare_json_list_to_table(from_json(@response), table)
end

Then /^I should receive a json hash like:$/ do |table|
  compare_json_hash_to_table_row_hash(from_json(@response), table.hashes.first)
end

Given /^the existing ([a-zA-Z0-9]+s):$/ do |klasses, table|
  klass = klasses.singularize.camelize.constantize
  table.hashes.each do |row|
    klass.make(row) #uses machinist
  end
end

notes.md

=== Notes

I have made some changes so that this uses factory_girl and hashie