[Javascript] Problems on deserialize text type and on file response

Hi,
I'm testing my api on the generated nodejs(javascript) client. I've found two problems, that break the client when called.
First:
when I've a call that return text/plain, SuperAgent initialize the body to {}, so data it's never null and doesn't verify the if condition, and in the end it gives an error.

I've done a fix for my case, just adding this line in the if clauses
"if (data == null || (returnType==='String' && Object.keys(data).length === 0 && data.constructor === Object))" but I think this is a bug and has to be correct

Second:
I've a call where the response is a file

And this is fine on other language like java or ruby, but not on javascript. It gives this error:

Thanks in advance for support

I'm using Swagger-codegen version 2.2.0

Reproduce both failures with the generated Node.js client using an API response of text/plain and another returning a file. Start by inspecting the generated JavaScript deserialization and file-response handling, then verify that text responses and file responses complete without the reported errors.