如何修复“没有将字符串隐式转换为哈希”

Question

I am trying to run a test with RSpec but it always returns the same error:

DevicesController#update when user is a manager must update any device
     Failure/Error: put device_path device_id, params: params, headers: { 'Content-Type': 'application/vnd.api+json' }

     TypeError:
       no implicit conversion of String into Hash

My function with the request params:

def update_params(device, device_id)
  {
    data: {
      id: device.id,
      type: 'device',
      attributes: {
        device_id: device_id 
      }
    }
  }.to_json
end

My test using factories:

context 'when user is a manager' do
  let(:user) { create(:manager).account }
  let(:firebase_token) { Faker::Crypto.sha1 }
  let(:device_id) { physical_device.id }
  let(:params) { update_params(physical_device, firebase_token) }
  it 'must update any device' do
    expect(Device.find(device_id).device_id).to eq(firebase_token)
  end
end

The request OS update device:

put device_path device_id, params: params, headers: { 'Content-Type': 'application/vnd.api+json' }

Answer 1

ActionController::TestCase expects the params to be a hash (like the headers ).

But the params you pass to this method call

put device_path device_id, params: params, headers: { 'Content-Type': 'application/vnd.api+json' }

are generated by the update_params method and that method calls to_json on the generated hash and therefore returns a JSON string .

Just remove the .to_json from the last line of the update_params method and you should be fine.