Validation Errors in 0.5.0

[mbleigh]

I'm just posting this to see if anyone else has run into this...I tried to upgrade Divshot to Grape 0.5.0 and started immediately seeing unexpected 400 errors for "missing" required parameters that were present in the request. Here's what I've determined so far:

1. It only occurs when posting a request body that needs to be parsed (in my case, json)
2. It seems to be caused by the validator params request taking place before the Formatter middleware has had a chance to parse the request body.
3. I haven't been able to create a spec that repros it.

Is anyone else experiencing this issue? I'm still investigating.

[mbleigh]

Update: This can be solved by removing memoization in Grape::Request#params. What appears to be happening is params is called before the Formatter has run, then it's memoized so the value is frozen without the results of the parsed input.

[mbleigh]

Update: Tracked it down. By moving memoization to the request level, any Grape middleware that is added to the stack before the formatter has the potential to freeze the value. Commit coming momentarily.

[dblock]

Re: spec. What middleware are you inserting before the formatter? I tried to insert a dummy middleware before the formatter that would do something to the request, but that didn't produce the desired error. Is it possible that that middleware needs to be fixed instead of removing ||= here?

[mbleigh]

It was the Grape OAuth2 middleware (it has to be something that inherits from Grape::Middleware::Base). I'll try to contribute a minimal spec that breaks under the old code.

[dblock]

@mbleigh, I almost re-added this ||= again. I still don't understand why 3b1ca79 was necessary.

Maybe another way to solve this is to assign @env['grape.request.params'] and @env['grape.request.headers'] elsewhere, in a global middleware?

require 'grape/middleware/base'

module Grape
  module Middleware
    class Globals < Base
      def before
        @env['grape.request'] = Grape::Request.new(@env)
        @env['grape.request.headers'] = request.headers
        @env['grape.request.params'] = request.params if @env['rack.input']
      end
    end
  end
end

We could then try to stop creating Grape::Request in other places and rely on these to exist at all times?

[dblock]

@mbleigh I am pretty sure this is fixed via #512, because formatter will now use its own Rack::Request and therefore work independently. This was a chicken-and-egg problem in the OAuth middleware. I am going to put memoization back in at request level, see if your issue is back.