Ruby on Rails -- NilClass error on Faraday GET request - ruby-on-rails

Question

Using Rails 5.1.4, Ruby 2.4
I am attempting to connect to an API using Faraday which I've done before without issue, but I'm getting the following error when I run RSpec:
SearchController GET #index returns http success
Failure/Error: response = #conn.get("/congress/v1/members/house/#{state}/current.json")
NoMethodError:
undefined method `get' for nil:NilClass
Did you mean? gem
# ./app/controllers/search_controller.rb:9:in `block in index'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/faraday-0.13.1/lib/faraday/connection.rb:88:in `initialize'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/faraday-0.13.1/lib/faraday.rb:67:in `new'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/faraday-0.13.1/lib/faraday.rb:67:in `new'
# ./app/controllers/search_controller.rb:5:in `index'
# ./spec/controllers/search_controller_spec.rb:7:in `block (3 levels) in <top (required)>'
2) user can search for house members user submits a valid state name
Failure/Error: response = #conn.get("/congress/v1/members/house/#{state}/current.json")
NoMethodError:
undefined method `get' for nil:NilClass
Did you mean? gem
# ./app/controllers/search_controller.rb:9:in `block in index'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/faraday-0.13.1/lib/faraday/connection.rb:88:in `initialize'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/faraday-0.13.1/lib/faraday.rb:67:in `new'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/faraday-0.13.1/lib/faraday.rb:67:in `new'
# ./app/controllers/search_controller.rb:5:in `index'
# /Users/user/.rvm/gems/ruby-2.4.0#global/gems/rack-2.0.3/lib/rack/etag.rb:25:in `call'
# /Users/user/.rvm/gems/ruby-2.4.0#global/gems/rack-2.0.3/lib/rack/conditional_get.rb:25:in `call'
# /Users/user/.rvm/gems/ruby-2.4.0#global/gems/rack-2.0.3/lib/rack/head.rb:12:in `call'
# /Users/user/.rvm/gems/ruby-2.4.0#global/gems/rack-2.0.3/lib/rack/session/abstract/id.rb:232:in `context'
# /Users/user/.rvm/gems/ruby-2.4.0#global/gems/rack-2.0.3/lib/rack/session/abstract/id.rb:226:in `call'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/railties-5.1.4/lib/rails/rack/logger.rb:36:in `call_app'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/railties-5.1.4/lib/rails/rack/logger.rb:24:in `block in call'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/railties-5.1.4/lib/rails/rack/logger.rb:24:in `call'
# /Users/user/.rvm/gems/ruby-2.4.0#global/gems/rack-2.0.3/lib/rack/method_override.rb:22:in `call'
# /Users/user/.rvm/gems/ruby-2.4.0#global/gems/rack-2.0.3/lib/rack/runtime.rb:22:in `call'
# /Users/user/.rvm/gems/ruby-2.4.0#global/gems/rack-2.0.3/lib/rack/sendfile.rb:111:in `call'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/railties-5.1.4/lib/rails/engine.rb:522:in `call'
# /Users/user/.rvm/gems/ruby-2.4.0#global/gems/rack-2.0.3/lib/rack/urlmap.rb:68:in `block in call'
# /Users/user/.rvm/gems/ruby-2.4.0#global/gems/rack-2.0.3/lib/rack/urlmap.rb:53:in `each'
# /Users/user/.rvm/gems/ruby-2.4.0#global/gems/rack-2.0.3/lib/rack/urlmap.rb:53:in `call'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/rack-test-0.7.0/lib/rack/mock_session.rb:30:in `request'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/rack-test-0.7.0/lib/rack/test.rb:249:in `process_request'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/rack-test-0.7.0/lib/rack/test.rb:59:in `get'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/capybara-2.15.1/lib/capybara/rack_test/browser.rb:69:in `process'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/capybara-2.15.1/lib/capybara/rack_test/browser.rb:41:in `process_and_follow_redirects'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/capybara-2.15.1/lib/capybara/rack_test/browser.rb:32:in `submit'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/capybara-2.15.1/lib/capybara/rack_test/form.rb:78:in `submit'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/capybara-2.15.1/lib/capybara/rack_test/node.rb:64:in `click'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/capybara-2.15.1/lib/capybara/node/element.rb:143:in `block in click'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/capybara-2.15.1/lib/capybara/node/base.rb:85:in `synchronize'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/capybara-2.15.1/lib/capybara/node/element.rb:143:in `click'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/capybara-2.15.1/lib/capybara/node/actions.rb:25:in `click_link_or_button'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/capybara-2.15.1/lib/capybara/session.rb:776:in `block (2 levels) in <class:Session>'
# /Users/user/.rvm/gems/ruby-2.4.0/gems/capybara-2.15.1/lib/capybara/dsl.rb:50:in `block (2 levels) in <module:DSL>'
# ./spec/features/user_can_search_by_state_spec.rb:11:in `block (2 levels) in <top (required)>'
Here is my Search controller, where the logic resides until I can fix this error and extract it elsewhere:
class SearchController < ApplicationController
def index
state = params[:state]
#conn = Faraday.new(url: "https://api.propublica.org") do |faraday|
faraday.headers["X-API-KEY"] = "<$MY-API-KEY>"
faraday.adapter Faraday.default_adapter
response = #conn.get("/congress/v1/members/house/#{state}/current.json")
results = JSON.parse(response.body, symbolize_names: true)[:results]
#members = results.map do |result|
Member.new(result)
end
end
end
end
And to be thorough, here is my Member model:
class Member
attr_reader :name,
:role,
:party,
:district,
:seniority
def initialize(attributes = {})
#name = attributes[:name]
#role = attributes[:role]
#party = attributes[:party]
#district = attributes[:district]
#seniority = attributes[:seniority]
end
end

Answer 1

#conn is not being properly defined, so when it tries to call #conn.get it's really calling nil.get which raises undefined method get for nil. Ensure you have defined #conn before you try to reference it. I have cleaned up your example to show the issue:
class SearchController < ApplicationController
def index
state = params[:state]
#conn = Faraday.new(url: "https://api.propublica.org") do |faraday|
faraday.headers["X-API-KEY"] = "<$MY-API-KEY>"
faraday.adapter Faraday.default_adapter
# you are trying to reference #conn here
response = #conn.get("/congress/v1/members/house/#{state}/current.json")
results = JSON.parse(response.body, symbolize_names: true)[:results]
#members = results.map do |result|
Member.new(result)
end
end # but #conn is not defined until you get here
end
end
If you refactor your code, it should look something more like this:
class SearchController < ApplicationController
def index
state = params[:state]
# fully define your #conn object
#conn = Faraday.new(url: "https://api.propublica.org") do |faraday|
faraday.headers["X-API-KEY"] = "<$MY-API-KEY>"
faraday.adapter Faraday.default_adapter
end
# now you can reference it
response = #conn.get("/congress/v1/members/house/#{state}/current.json")
results = JSON.parse(response.body, symbolize_names: true)[:results]
#members = results.map do |result|
Member.new(result)
end
end
end