Ruby stubbing with faraday, can't get it to work

Question

Sorry for the title, I'm too frustrated to come up with anything better right now.

I have a class, Judge, which has a method #stats. This stats method is supposed to send a GET request to an api and get some data as response. I'm trying to test this and stub the stats method so that I don't perform an actual request. This is what my test looks like:

describe Judge do
  describe '.stats' do

    context 'when success' do
      subject { Judge.stats }

      it 'returns stats' do
        allow(Faraday).to receive(:get).and_return('some data')

        expect(subject.status).to eq 200
        expect(subject).to be_success
      end
    end
  end
end

This is the class I'm testing:

class Judge

  def self.stats
    Faraday.get "some-domain-dot-com/stats"
  end

end

This currently gives me the error: Faraday does not implement: get So How do you stub this with faraday? I have seen methods like:

    stubs = Faraday::Adapter::Test::Stubs.new do |stub|
      stub.get('http://stats-api.com') { [200, {}, 'Lorem ipsum'] }
    end

But I can't seem to apply it the right way. What am I missing here?

Answer 1

Note that Faraday.new returns an instance of Faraday::Connection, not Faraday. So you can try using

allow_any_instance_of(Faraday::Connection).to receive(:get).and_return("some data")

Note that I don't know if returning "some data" as shown in your question is correct, because Faraday::Connection.get should return a response object, which would include the body and status code instead of a string. You might try something like this:

allow_any_instance_of(Faraday::Connection).to receive(:get).and_return(
   double("response", status: 200, body: "some data")
)

Here's a rails console that shows the class you get back from Faraday.new

$ rails c
Loading development environment (Rails 4.1.5)
2.1.2 :001 > fara = Faraday.new
 => #<Faraday::Connection:0x0000010abcdd28 @parallel_manager=nil, @headers={"User-Agent"=>"Faraday v0.9.1"}, @params={}, @options=#<Faraday::RequestOptions (empty)>, @ssl=#<Faraday::SSLOptions (empty)>, @default_parallel_manager=nil, @builder=#<Faraday::RackBuilder:0x0000010abcd990 @handlers=[Faraday::Request::UrlEncoded, Faraday::Adapter::NetHttp]>, @url_prefix=#<URI::HTTP:0x0000010abcd378 URL:http:/>, @proxy=nil>
2.1.2 :002 > fara.class
 => Faraday::Connection

Answer 2

Coming to this late, but incase anyone else is too, this is what worked for me - a combination of the approaches above:

  let(:json_data) { File.read Rails.root.join("..", "fixtures", "ror", "501100000267.json") }

  before do
    allow_any_instance_of(Faraday::Connection).to receive(:get).and_return(
      double(Faraday::Response, status: 200, body: json_data, success?: true)
    )
  end

Answer 3

Faraday the class has no get method, only the instance does. Since you are using this in a class method what you can do is something like this:

class Judge
  def self.stats
    connection.get "some-domain-dot-com/stats"
  end

  def self.connection=(val)
    @connection = val
  end

  def self.connection
    @connection ||= Faraday.new(some stuff to build up connection)
  end
end

Then in your test you can just set up a double:

let(:connection) { double :connection, get: nil }
before do
  allow(connection).to receive(:get).with("some-domain-dot-com/stats").and_return('some data')
  Judge.connection = connection
end

Answer 4

I ran into the same problem with Faraday::Adapter::Test::Stubs erroring with Faraday does not implement: get. It seems you need to set stubs to a Faraday adapter, like so:

  stubs = Faraday::Adapter::Test::Stubs.new do |stub|
    stub.get("some-domain-dot-com/stats") { |env| [200, {}, 'egg'] }
  end

  test = Faraday.new do |builder|
    builder.adapter :test, stubs
  end

  allow(Faraday).to receive(:new).and_return(test)

  expect(Judge.stats.body).to eq "egg"
  expect(Judge.stats.status).to eq 200

Answer 5

A better way to do this, rather than using allow_any_instance_of, is to set the default connection for Faraday, so that Faraday.get will use the connection you setup in your tests.

For example:

  let(:stubs) { Faraday::Adapter::Test::Stubs.new }
  let(:conn) { Faraday.new { |b| b.adapter(:test, stubs) } }

  before do
    stubs.get('/maps/api/place/details/json') do |_env|
      [
        200,
        { 'Content-Type': 'application/json' },
        { 'result' => { 'photos' => [] } }.to_json
      ]
    end

    Faraday.default_connection = conn
  end

  after do
    Faraday.default_connection = nil
  end