API Test/Code

api.stubLists.reason.rb

      def find_list_id(name)
        @api.lists["data"].detect { |r| r["name"] == name }["id"]
      end

      def list_id
        @list_id ||= find_list_id(@list_name)
      end

code.rb

module Spree::Chimpy
  module Interface
    class List
      delegate :log, to: Spree::Chimpy

      def initialize(list_name, segment_name, double_opt_in, list_id)
        @api           = Spree::Chimpy.api
        @list_id       = list_id
        @segment_name  = segment_name
        @double_opt_in = double_opt_in
        @list_name     = list_name
      end

      def api_call
        @api.lists
      end

      def subscribe(email, merge_vars = {}, options = {})
        log "Subscribing #{email} to #{@list_name}"

        api_call.subscribe(id: list_id, email_address: email, merge_vars: merge_vars, update_existing: true, double_optin: @double_opt_in, email_type: 'html')

        segment([email]) if options[:customer]
      end

output.sh

Failures:

  1) Spree::Chimpy::Interface::List subscribes
     Failure/Error: interface.subscribe("[email protected]", 'SIZE' => '10')
     NoMethodError:
       undefined method `subscribe' for {"data"=>[{"name"=>"Members", "id"=>"a3d3"}]}:Hash
     # ./lib/spree/chimpy/interface/list.rb:21:in `subscribe'
     # ./spec/lib/list_interface_spec.rb:23:in `block (2 levels) in <top (required)>'

  2) Spree::Chimpy::Interface::List segments users
     Failure/Error: interface.subscribe("[email protected]", {'SIZE' => '10'}, {customer: true})
     NoMethodError:
       undefined method `subscribe' for {"data"=>[{"name"=>"Members", "id"=>"a3d3"}]}:Hash
     # ./lib/spree/chimpy/interface/list.rb:21:in `subscribe'
     # ./spec/lib/list_interface_spec.rb:47:in `block

test.rb

require 'pry-debugger'

describe Spree::Chimpy::Interface::List do
  let(:interface) { described_class.new('Members', 'customers', true, nil) }
  let(:api)       { double(:api) }
  let(:api_call)  { double(:api_call) }
  let(:data)      { {"data" => [{"name" => "Members", "id" => "a3d3" }]} }

  before do
    Spree::Chimpy::Config.key = '1234'
    Mailchimp::API.should_receive(:new).with('1234', { timeout: 60 }).and_return(api)
    api.stub(:lists).and_return(data)
  end

  it "subscribes" do
    expect{ api.lists }.to receive(:subscribe).
      with({:id => 'a3d3',
            :email_address => '[email protected]',
            :merge_vars => {'SIZE' => '10'},
            :email_type => 'html', :double_optin => true,
            :update_existing => true})
    interface.subscribe("[email protected]", 'SIZE' => '10')
  end