Rails app with Faraday: Problem refactoring Faraday::new() without url parameter - ruby-on-rails

Question

I'm refactoring some code in a Rails app consisting of several microservices. The faraday_middleware gem is used for communication between services.
I managed to replace several calls to Faraday::new() in different helper files with one single call to Faraday::new() in a ServiceConnectionHelper module. All of these replaced calls had an url parameter: Faraday.new(url: url)
But there's two very similar pieces of code left that I'd like to get rid of. In these cases, there is no url parameter. This is the old (working) code:
# This code calls the connection function below
def create(resource)
params = {
resource_id: resource.to_param,
version: resource.version,
file: Faraday::UploadIO.new(resource.file.path, resource.mime_type.to_s, resource.file.original_filename)
}
res = connection(resource.authorization).post(foobar_url, params)
return res.body['id'] if [200, 201].include?(res.status)
raise UploadError, res.body['error']
end
# connection function
def connection(authorization_header = nil)
Faraday.new do |conn|
conn.use FaradayMiddleware::FollowRedirects, limit: 5
conn.request :multipart
conn.request :url_encoded
conn.use FaradayMiddleware::ParseJson, content_type: 'application/json'
conn.adapter Faraday.default_adapter
conn.headers['Accept'] = 'application/json'
conn.headers['Authorization'] = authorization_header unless authorization_header.nil?
end
end
This is the code I want to use instead. It's not working because of an error inside the create function. When I catch it and log it, e.inspect is just #<UploadError: Please specify a file>
# Small change only: Te other service's url is computed in the ServiceConnectionHelper module
def create(resource)
params = {
resource_id: resource.to_param,
version: resource.version,
file: Faraday::UploadIO.new(resource.file.path, resource.mime_type.to_s, resource.file.original_filename)
}
# This is were the error happens
res = connection(resource.authorization).post('/', params)
return res.body['id'] if [200, 201].include?(res.status)
raise UploadError, res.body['error']
end
# connection function calls the new helper module now
def connection(authorization_header = nil)
ServiceConnectionHelper.connection('foobar', authorization_header)
end
# the new module
module ServiceConnectionHelper
class << self
def connection(service, oauth_token = nil)
url = service_url(service)
Faraday.new(url: url) do |conn|
conn.use FaradayMiddleware::FollowRedirects, limit: 5
conn.request :url_encoded
conn.adapter Faraday.default_adapter
conn.request :multipart
conn.use FaradayMiddleware::ParseJson, content_type: 'application/json'
conn.headers['Accept'] = 'application/json'
conn.headers['Authorization'] = oauth_token if oauth_token
end
end
private
def service_url(service)
url = case service
when 'foobar' then 'foobar_url_as_a_string'
# the same for other services
end
url
end
end
end
What can I do to make the ServiceConnectionHelper work in this case?

Answer 1

Compared of your first example, the order of request changed:
conn.request :url_encoded
conn.request :multipart