webstub

WebStub

What if WebMock and NSURLProtocol had a baby?

Features

• Supports most any HTTP library that is built on NSURLConnection / NSURLSession
• Request matching based upon HTTP method, URI, and body
• Optionally, disable real network access
• Familiar, delicious syntax
• Bacon integration

Installation

Update your Gemfile:

gem "webstub"

Bundle:

$ bundle install

Usage

• Add the following line to the top-most describe block in your spec:

  extend WebStub::SpecHelpers

• Use the following methods to control the use of request stubbing:

  • disable_network_access!
  • enable_network_access!
  • stub_request
  • reset_stubs

Example Spec

describe "Example" do
  extend WebStub::SpecHelpers

  describe "Stubbing a GET request to return a simple response after a delay" do
    it "retrieves the front page" do
      stub_request(:get, "http://example.com/").
        to_return(body: "Hello!", content_type: "text/plain", delay: 0.3)

      @body = nil
      @api.get_index do |body, error|
        @body = body
        resume
      end

      wait_max 1.0 do
        @body.should.be == "Hello!"
      end
    end
  end

  describe "Stubbing a GET request to return JSON" do
    it "retrieves suggestions" do
      stub_request(:get, "https://example.com/suggestions?q=mu").
        to_return(json: { suggestions: ["muse"] })

      @suggestions = nil
      @api.get_suggestions("mu") do |results, error|
        @suggestions = results
        resume
      end

      wait_max 1.0 do
        @suggestions.should.not.be.empty
      end
    end
  end

  describe "Stubbing a POST request to return JSON" do
    it "handles a POST request" do
      stub_request(:post, "https://example.com/action").
        with(body: { q: "unsustainable" }).
        to_return(json: [ { album: "The 2nd Law", release_date: "2012-10-01", artist: "Muse" } ])

      @results = nil
      @api.get_album_info_for_track("unsustainable") do |results, error|
        @results = results
        resume
      end

      wait_max 1.0 do
        @results.should.not.be.empty
      end
    end
  end

  describe "Stubbing a GET request to fail" do
    it "returns an NSError with the NSURLError domain" do
      stub_request(:get, "https://example.com/action").
        to_fail(code: NSURLErrorNotConnectedToInternet)

      @error = nil
      @api.get_albums do |results, error|
        @error = error
        resume
      end

      wait_max 1.0 do
        @error.code.should == NSURLErrorNotConnectedToInternet
      end
    end
  end
end

Conventions

• The URL is matched exactly as is right now (hence query parameters need to be included and encoded)
• The with method's body option accepts either a Hash or a String:
  • Hashes are assumed to be form data (with a application/x-www-form-urlencoded content type)
  • Strings are matched as is
• The to_return method accepts a few options:
  • json: accepts either a Hash, Array or a String. If a Hash or Array is provided, it will be converted to JSON. Strings are returned as is, with the Content-Type set to application/json.
  • body: accepts a String, and returns it as-is
  • content_type: sets the Content-Type when using the body parameter
  • status_code: sets the integer Status Code of the response. Defaults to 200.
• The to_redirect method accepts:
  • url: String of the URL to redirect to (required)
  • All options supported by to_return except for status_code
• The to_fail method accepts one of the following options:
  • code: NSURLErrorDomain error code
  • error: NSError to fail the request with

Expectations

Sometimes, you may just want to check that the request has been made to a given URL. In this case, you can use the requested? method of the stub returned by stub_request:

describe Elevate::HTTP do
  extend WebStub::SpecHelpers

  describe ".get" do
    it "synchronously issues a HTTP GET request" do
      stub = stub_request(:get, "http://www.example.com/")

      Elevate::HTTP.get("http://www.example.com/")

      stub.should.be.requested
    end
  end
end

Callbacks

Sometimes, you may want to inspect the request made for a given URL. In this case, you can use the with_callback method of the stub returned by stub_request to add a callback hook:

describe Elevate:HTTP do
  extend WebStub::SpecHelpers

  describe ".post" do
    it "synchronously issues an HTTP POST request" do
      stub = stub_request(:post, "http://www.example.com/")

      stub.with_callback do |headers, body|
        headers.kind_of?(Hash).should == true
        body.kind_of?(Hash).should == true
        body.should == {"key" => "value"}
      end

      Elevate::HTTP.post("http://www.example.com/", json: {key: "value"})
    end
  end
end

Caveats

While WebStub supports NSURLSession, it does not support background sessions, as they don't allow the use of custom NSURLProtocol classes.

TODO

• Handle query params similarly to form data