fake_mux_api.rb

# Taken from https://thoughtbot.com/blog/how-to-stub-external-services-in-tests
require 'sinatra/base'

class FakeMuxApi < Sinatra::Base

  configure :production, :development do
    enable :logging
  end

  post '/video/v1/assets' do
    payload = JSON.parse(request.body.read).symbolize_keys
    plain_json_response 200, { data: {
      "status": "preparing",
      "source_asset_id": "sadfasdfasdlkgfdy7g798a6sd8f6786asd57a",
      "playback_ids": [
        {
          "policy": "signed",
          "id": "sxfd6gx8adsz89v6arg89hex7ry9gs67v9da"
        }
      ],
      "passthrough": "encoder:9 client_reference:ZXGRDTFJDRSTHGERY event:94",
      "mp4_support": "standard",
      "master_access": "temporary",
      "id": "XEGZERFCWDTXTAXTEGZR",
      "created_at": 1617305279
    } }
  end

  get '/video/v1/assets/:id' do
    json_response 200, "asset.find.%s.json" % params[:id]
  end

  delete '/video/v1/assets/:id' do
    plain_json_response 204, {}
  end

  put '/video/v1/live-streams/:id/disable' do
    plain_json_response 200, { data: {} }
  end

  put '/video/v1/live-streams/:id/enable' do
    plain_json_response 200, { data: {} }
  end

  get '/video/v1/delivery-usage' do
    if params[:timeframe][0].to_i < (Time.current - 90.days).beginning_of_day.to_i
      status 400
      '{"error":{"type":"invalid_parameters","messages":["invalid timeframe: start time must be in the last 90 days"]}}"}'
    else
      start = I18n.l(Time.at(params[:timeframe][0].to_i), format: "%Y%m%d-%H%M")
      stop  = I18n.l(Time.at(params[:timeframe][1].to_i), format: "%Y%m%d-%H%M")
      file_name = "delivery-usage.%s.%s.%s.json" % [params[:asset_id], start, stop]
      json_response 200, file_name
    end
  end

  # Catch all Routes
  get '/*' do
    throw [:GET, params]
  end

  post '/*' do
    throw [:POST, params]
  end

  put '/*' do
    throw [:PUT, params]
  end

  # start the server if ruby file executed directly
  run! if app_file == $0

  private

    def plain_json_response(response_code, hash)
      content_type "application/json"
      status response_code
      hash.to_json
    end

    def json_response(response_code, file_name)
      content_type "application/json"
      file_path = Rails.root.join('spec', 'fixtures', 'mux', 'api', "#{file_name}")
      if File.exist?(file_path)
        status response_code
        File.open(file_path, 'rb').read
      else
        $stdout.puts "404 Not Found: #{file_path}"
        status 404
        "404 Not Found: #{file_path}"
      end
    rescue => e
      abort(e.message)
    end

end

rails_helper.rb

require_relative 'support/fake_mux_api.rb'
WebMock.disable_net_connect!(allow_localhost: true)
RSpec.configure do |config|
  config.before(:each) do
    stub_request(:any, /api\.mux\.com/).to_rack(FakeMuxApi)
  end
end