Rack 3.1 fixes (#2449)

* Add Grape::Http::Headers::TRANSFER_ENCODING
Fix spec regarding content-length on stream

* Add CHANGELOG.md

.github/workflows/test.yml

@@ -24,7 +24,7 @@ jobs:
       fail-fast: false
       matrix:
         ruby: ['2.7', '3.0', '3.1', '3.2', '3.3']
-        gemfile: [Gemfile, gemfiles/rack_2_0.gemfile, gemfiles/rack_3_0.gemfile, gemfiles/rails_6_0.gemfile, gemfiles/rails_6_1.gemfile, gemfiles/rails_7_0.gemfile, gemfiles/rails_7_1.gemfile]
+        gemfile: [Gemfile, gemfiles/rack_2_0.gemfile, gemfiles/rack_3_0.gemfile, gemfiles/rack_3_1.gemfile, gemfiles/rails_6_0.gemfile, gemfiles/rails_6_1.gemfile, gemfiles/rails_7_0.gemfile, gemfiles/rails_7_1.gemfile]
         specs: ['spec --exclude-pattern=spec/integration/**/*_spec.rb']
         include:
           - ruby: '2.7'

CHANGELOG.md

@@ -46,6 +46,7 @@
 * [#2378](https://github.com/ruby-grape/grape/pull/2378): Do not overwrite `route_param` with a regular one if they share same name - [@arg](https://github.com/arg).
 * [#2444](https://github.com/ruby-grape/grape/pull/2444): Replace method_missing in endpoint - [@ericproulx](https://github.com/ericproulx).
 * [#2441](https://github.com/ruby-grape/grape/pull/2441): Optimize memory alloc and retained - [@ericproulx](https://github.com/ericproulx).
+* [#2449](https://github.com/ruby-grape/grape/pull/2449): Rack 3.1 fixes - [@ericproulx](https://github.com/ericproulx).
 * Your contribution here.
 
 ### 2.0.0 (2023/11/11)

gemfiles/rack_3_1.gemfile

@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+eval_gemfile '../Gemfile'
+
+gem 'rack', '~> 3.1'

lib/grape/dsl/inside_route.rb

@@ -350,7 +350,7 @@ def stream(value = nil)
         return if value.nil? && @stream.nil?
 
         header Rack::CONTENT_LENGTH, nil
-        header Rack::TRANSFER_ENCODING, nil
+        header Grape::Http::Headers::TRANSFER_ENCODING, nil
         header Rack::CACHE_CONTROL, 'no-cache' # Skips ETag generation (reading the response up front)
         if value.is_a?(String)
           file_body = Grape::ServeStream::FileBody.new(value)

lib/grape/http/headers.rb

@@ -10,6 +10,7 @@ module Headers
       ALLOW = 'Allow'
       LOCATION = 'Location'
       X_CASCADE = 'X-Cascade'
+      TRANSFER_ENCODING = 'Transfer-Encoding'
 
       SUPPORTED_METHODS = [
         Rack::GET,

spec/grape/api_spec.rb

@@ -1252,7 +1252,7 @@ def to_txt
       expect(last_response.content_type).to eq('text/plain')
       expect(last_response.content_length).to be_nil
       expect(last_response.headers[Rack::CACHE_CONTROL]).to eq('no-cache')
-      expect(last_response.headers[Rack::TRANSFER_ENCODING]).to eq('chunked')
+      expect(last_response.headers[Grape::Http::Headers::TRANSFER_ENCODING]).to eq('chunked')
 
       expect(last_response.body).to eq("c\r\nThis is some\r\nd\r\n file content\r\n0\r\n\r\n")
     end

spec/grape/dsl/inside_route_spec.rb

@@ -247,7 +247,7 @@ def initialize
         before do
           subject.header Rack::CACHE_CONTROL, 'cache'
           subject.header Rack::CONTENT_LENGTH, 123
-          subject.header Rack::TRANSFER_ENCODING, 'base64'
+          subject.header Grape::Http::Headers::TRANSFER_ENCODING, 'base64'
         end
 
         it 'sends no deprecation warnings' do
@@ -277,7 +277,7 @@ def initialize
         it 'does not change the Transfer-Encoding header' do
           subject.sendfile file_path
 
-          expect(subject.header[Rack::TRANSFER_ENCODING]).to eq 'base64'
+          expect(subject.header[Grape::Http::Headers::TRANSFER_ENCODING]).to eq 'base64'
         end
       end
 
@@ -308,7 +308,7 @@ def initialize
         before do
           subject.header Rack::CACHE_CONTROL, 'cache'
           subject.header Rack::CONTENT_LENGTH, 123
-          subject.header Rack::TRANSFER_ENCODING, 'base64'
+          subject.header Grape::Http::Headers::TRANSFER_ENCODING, 'base64'
         end
 
         it 'emits no deprecation warnings' do
@@ -344,7 +344,7 @@ def initialize
         it 'sets Transfer-Encoding header to nil' do
           subject.stream file_path
 
-          expect(subject.header[Rack::TRANSFER_ENCODING]).to be_nil
+          expect(subject.header[Grape::Http::Headers::TRANSFER_ENCODING]).to be_nil
         end
       end
 
@@ -358,7 +358,7 @@ def initialize
         before do
           subject.header Rack::CACHE_CONTROL, 'cache'
           subject.header Rack::CONTENT_LENGTH, 123
-          subject.header Rack::TRANSFER_ENCODING, 'base64'
+          subject.header Grape::Http::Headers::TRANSFER_ENCODING, 'base64'
         end
 
         it 'emits no deprecation warnings' do
@@ -388,7 +388,7 @@ def initialize
         it 'sets Transfer-Encoding header to nil' do
           subject.stream stream_object
 
-          expect(subject.header[Rack::TRANSFER_ENCODING]).to be_nil
+          expect(subject.header[Grape::Http::Headers::TRANSFER_ENCODING]).to be_nil
         end
       end
 

spec/grape/middleware/formatter_spec.rb

@@ -453,12 +453,19 @@ def to_xml
     let(:env) do
       { Rack::PATH_INFO => '/somewhere', Grape::Http::Headers::HTTP_ACCEPT => 'application/json' }
     end
+    let(:headers) do
+      if Gem::Version.new(Rack.release) < Gem::Version.new('3.1')
+        { Rack::CONTENT_TYPE => 'application/json', Rack::CONTENT_LENGTH => body.bytesize.to_s }
+      else
+        { Rack::CONTENT_TYPE => 'application/json' }
+      end
+    end
 
     it 'returns a file response' do
       expect(file).to receive(:each).and_yield(body)
       r = Rack::MockResponse[*subject.call(env)]
       expect(r).to be_successful
-      expect(r.headers).to eq({ Rack::CONTENT_TYPE => 'application/json', Rack::CONTENT_LENGTH => body.bytesize.to_s })
+      expect(r.headers).to eq(headers)
       expect(r.body).to eq('data')
     end
   end

spec/support/chunked_response.rb

@@ -58,9 +58,9 @@ def call(env)
 
     if !Rack::Utils::STATUS_WITH_NO_ENTITY_BODY.key?(status.to_i) &&
        !headers[Rack::CONTENT_LENGTH] &&
-       !headers[Rack::TRANSFER_ENCODING]
+       !headers[Grape::Http::Headers::TRANSFER_ENCODING]
 
-      headers[Rack::TRANSFER_ENCODING] = 'chunked'
+      headers[Grape::Http::Headers::TRANSFER_ENCODING] = 'chunked'
       response[2] = if headers['trailer']
                       TrailerBody.new(body)
                     else