A gem for testing Ruby on Rails web APIs by simulating a client.
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A gem for testing Ruby on Rails web APIs by simulating a client.


In your Gemfile, add this line:

gem "flunk"


We write mostly JSON APIs using Rails, not your traditional web app, so we wanted a better way to test our JSON APIs. This is flunk.


In each test block you call a series of methods as necessary:

  • desc: In the future, a documentation generator will be added and this will be used to determine if the test should be documented as an API method.
  • path: The relative URL for the resource.
  • method: :get, :post, :put or :delete
  • username: For authentication using basic auth.
  • password: For authentication using basic auth.
  • body: The body of the request.
  • status: This method actually acts like an assertion. It is what the status of the response SHOULD be. An error will be thrown if it doesn't match.
  • assertions: A block of of assertions you call to verify the response was what it should have been.

Once you call assertions, the request is fired and a result method is available within the assertions block containing the response.


To generate a flunk test:

rails g flunk_test User

This will create an integration test: test/integration/users_test.rb


It's your typical rails integration test, but inherits from Flunk:

class UsersTest < Flunk

  setup do
  	@user = FactoryGirl.create(:user)

You write tests that SHOULD pass to test your app's basic functionality all works:

  test "User", "Create" do
    desc      "Creating a new Langwich user."
  	path			"signup"
  	method		:post
  	body			user: attrs = FactoryGirl.attributes_for(:user)
  	status		:created
    before {
      assert_equal 0, user.languages.count
    after {
      assert_equal result[:name],       attrs[:name]
      assert_equal result[:username],   attrs[:username]
      assert_equal result[:email],      attrs[:email]
      assert_not_nil result[:api_token]
      user = User.find_by_api_token result[:api_token]
      assert_equal 1, user.languages.count

  test "User", "Log In With Email" do
  	path			"login"
  	method		:get
  	body			username: @user.email, password: @user.password
  	status		:ok
    after {
      assert_not_nil result[:api_token]

  test "User", "Read" do
    desc      "Read a users information."
    path      "account"
    method    :get
    username  @user.api_token
    status    :ok

Then, write tests that SHOULDN'T pass to make sure your app rejects bad requests correctly/gracefully:

  flunk "User", "Create", "Missing username" do
    desc      "Attempting to create a user without a username."
    path      "signup"
    method    :post
    body      user: FactoryGirl.attributes_for(:user, username: nil)
    status    :unprocessable_entity

  flunk "User", "Create", "Username already taken" do
    path      "signup"
    method    :post
    body      user: FactoryGirl.attributes_for(:user, username: @user.username)
    status    :unprocessable_entity

Documentation Generation

Flunk can generate and organize a folder structure of Markdown files documenting your API calls while it tests. If you provide the desc for a test, a Markdown file will be created with all the information about that particular API endpoint. Finally, it will organize each Markdown file into a folder named for the resource it is acting upon.

By default, if it comes across a test with a "desc", it will place the docs in $RAILS_ROOT/docs/flunk/. You can customize this by putting this into an initializer:

if Rails.env.test?
  Flunk.config.doc_directory "docs/firehose-docs/api"
  Flunk.config.doc_base_url "https://api.firehoseapp.com"

The config method on the Flunk class returns a global Flunk instance, so you can set any property on it to be used as a default.

At Firehose, we have a few JSON-only apps that we use Flunk to test, so we have a submodule at docs/firehose-docs in each app and each app has Flunk dump the docs into a folder for that app. The Firehose API app dumps into the subfolder api. This allows us to easily have Flunk write our docs for us into a folder that is part of it's own public repo that contains all our documentation for all of our apps.

Here's an example of the Firehose Github repo that is our API docs: https://github.com/mysterioustrousers/firehose-docs


Flunk is included as a submodule in our project button and is used to test it. Please clone button, run git submodule update --init --recursive then rake to make sure the tests are passing for you before you begin. Then, make your changes in the flunk submodule, commit them and push them to your own fork and issue a pull request. Thanks!