ruby on rails - Testing POST method with rspec -

i want test post method receives client-side token, verify validity of token , based on creates or not record in database (it doesn't matter record). in controller

def create      uri = uri('https://graph.facebook.com/me')     params = { access_token: params[:access_token] }     uri.query = uri.encode_www_form(params)     response = net::http.get_response(uri)     ...     # parse response , create user     ... end 

in test controller

describe "post #create"     "response forbidden error code"         post :create, access_token: 'xxxxx'         expect(response.status).to eq(403)     end end 

the test method gives error

nomethoderror: undefined method `[]' nil:nilclass 

and points line of code create method:

params = { access_token: params[:access_token] } 

also, when test method in postman got same error. ideas doing wrong?