fixes #9: Can now change headers and body on client response

[GlenTiki]

You need to call .setHeaders(newHeaders) and .setBody(newBody) for modifying these values. The reason you can't shouldn't just assign .body is because they are used to build a cached request, and simply overwriting it would mean I would have to un-cache the request and build it every time the client makes the request, because wouldn't be able to effectively and efficiently detect when it has been changed... simply put, its a big no-no for perf. 😄

If you do need to assign directly to the body though, it is possible, you just need to rebuild your request like so:

const instance = autocannon({
    url: url,
    connections: 1000,
    duration: 10
  }, finishedBench)

  instance.on('response', function (client, statusCode, returnBytes, responseTime) {
    client.setHeaders({ .. })
    client.body = ...
    client.rebuildRequest()
  })

However, the preferred method of use is:

const instance = autocannon({
    url: url,
    connections: 1000,
    duration: 10
  }, finishedBench)

  instance.on('response', function (client, statusCode, returnBytes, responseTime) {
    client.setHeaders(...)
    client.setBody(...)
  })

Also, .headers cant be reassigned to, as I'm not what the .headers variable are for.

[mcollina]

I think you can avoid this.

[GlenTiki]

I'm not sure, as this will allow the user to assign to client.body and when the rebuildRequest() is called, it should pick up their assignments. However, I would prefer to take this out and just use .setBody(...) so its is a consistent api for headers and body.

[mcollina]

I agree with consistency. We should probably rename rebuildRequest to _rebuild().

[mcollina]

Unit tests are missing.

[mcollina]

This might be a perf issues, I know it's my code :(.

[GlenTiki]

Well, the request is built/cached once, unless users go crazy with the .setHeaders() and .setBody() call. If you this improved though, I'll need some guidance :)

[mcollina]

Let's talk about this later on :)

[mcollina]

Can you also add an example (maybe in the examples folder) where you are using this API?