Set response headers based on Rack version (ruby-grape#2355)

* Set response headers based on Rack version
* Use Rack.release instead of Rack::RELEASE
* Bumped to 1.9.0 and updated UPGRADING.md
* Added .rack3? method
* Removed headers_helper
* Updated README and UPGRADING

.github/workflows/test.yml

@@ -63,6 +63,16 @@ jobs:
       if: ${{ matrix.gemfile == 'multi_xml' }}
       run: bundle exec rspec spec/integration/multi_xml
 
+    - name: Run tests (spec/integration/rack/v2)
+      # rack_2_0.gemfile is equals to Gemfile
+      if: ${{ matrix.gemfile == 'rack_2_0' }}
+      run: bundle exec rspec spec/integration/rack/v2
+
+    - name: Run tests (spec/integration/rack/v3)
+      # rack_2_0.gemfile is equals to Gemfile
+      if: ${{ matrix.gemfile == 'rack_3_0' }}
+      run: bundle exec rspec spec/integration/rack/v3
+
     - name: Coveralls
       uses: coverallsapp/github-action@master
       with:

.rubocop_todo.yml

@@ -272,6 +272,8 @@ RSpec/FilePath:
     - 'spec/integration/eager_load/eager_load_spec.rb'
     - 'spec/integration/multi_json/json_spec.rb'
     - 'spec/integration/multi_xml/xml_spec.rb'
+    - 'spec/integration/rack/v2/headers_spec.rb'
+    - 'spec/integration/rack/v3/headers_spec.rb'
 
 # Offense count: 12
 # Configuration parameters: Max.

CHANGELOG.md

@@ -1,11 +1,12 @@
-### 1.8.1 (Next)
+### 1.9.0 (Next)
 
 #### Features
 
 * [#2353](https://github.com/ruby-grape/grape/pull/2353): Added Rails 7.1 support - [@ericproulx](https://github.com/ericproulx).
+* [#2355](https://github.com/ruby-grape/grape/pull/2355): Set response headers based on Rack version - [@schinery](https://github.com/schinery).
 * [#2360](https://github.com/ruby-grape/grape/pull/2360): Reduce gem size by removing specs - [@ericproulx](https://github.com/ericproulx).
 * Your contribution here.
-
+  
 #### Fixes
 
 * Your contribution here.

README.md

@@ -160,7 +160,7 @@ content negotiation, versioning and much more.
 
 ## Stable Release
 
-You're reading the documentation for the next release of Grape, which should be **1.8.1**.
+You're reading the documentation for the next release of Grape, which should be **1.9.0**.
 Please read [UPGRADING](UPGRADING.md) when upgrading from a previous version.
 The current stable release is [1.8.0](https://github.com/ruby-grape/grape/blob/v1.8.0/README.md).
 
@@ -2130,8 +2130,9 @@ curl -H "secret_PassWord: swordfish" ...
 
 The header name will have been normalized for you.
 
-- In the `header` helper names will be coerced into a capitalized kebab case.
-- In the `env` collection they appear in all uppercase, in snake case, and prefixed with 'HTTP_'.
+- In the `header` helper names will be coerced into a downcased kebab case as `secret-password` if using Rack 3.
+- In the `header` helper names will be coerced into a capitalized kebab case as `Secret-PassWord` if using Rack < 3.
+- In the `env` collection they appear in all uppercase, in snake case, and prefixed with 'HTTP_' as `HTTP_SECRET_PASSWORD`
 
 The header name will have been normalized per HTTP standards defined in [RFC2616 Section 4.2](https://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2) regardless of what is being sent by a client.
 

UPGRADING.md

@@ -1,6 +1,35 @@
 Upgrading Grape
 ===============
 
+### Upgrading to >= 1.9.0
+
+#### Headers
+
+As per [rack/rack#1592](https://github.com/rack/rack/issues/1592) Rack 3.0 is enforcing the HTTP/2 semantics, and thus treats all headers as lowercase. Starting with Grape 1.9.0, headers will be cased based on what version of Rack you are using.
+
+Given this request:
+
+```shell
+curl -H "Content-Type: application/json" -H "Secret-Password: foo" ...
+```
+
+If you are using Rack 3 in your application then the headers will be set to:
+
+```ruby
+{ "content-type" => "application/json", "secret-password" => "foo"}
+```
+
+This means if you are checking for header values in your application, you would need to change your code to use downcased keys. 
+
+```ruby
+get do
+  # This would use headers['Secret-Password'] in Rack < 3
+  error!('Unauthorized', 401) unless headers['secret-password'] == 'swordfish'
+end
+```
+
+See [#2355](https://github.com/ruby-grape/grape/pull/2355) for more information.
+
 ### Upgrading to >= 1.7.0
 
 #### Exceptions renaming

lib/grape.rb

@@ -42,6 +42,10 @@ def self.deprecator
     @deprecator ||= ActiveSupport::Deprecation.new('2.0', 'Grape')
   end
 
+  def self.rack3?
+    Gem::Version.new(::Rack.release) >= Gem::Version.new('3')
+  end
+
   eager_autoload do
     autoload :API
     autoload :Endpoint

lib/grape/dsl/inside_route.rb

@@ -185,7 +185,7 @@ def redirect(url, permanent: false, body: nil, **_options)
           status 302
           body_message ||= "This resource has been moved temporarily to #{url}."
         end
-        header 'Location', url
+        header Grape::Http::Headers::LOCATION, url
         content_type 'text/plain'
         body body_message
       end
@@ -328,9 +328,9 @@ def sendfile(value = nil)
       def stream(value = nil)
         return if value.nil? && @stream.nil?
 
-        header 'Content-Length', nil
-        header 'Transfer-Encoding', nil
-        header 'Cache-Control', 'no-cache' # Skips ETag generation (reading the response up front)
+        header Grape::Http::Headers::CONTENT_LENGTH, nil
+        header Grape::Http::Headers::TRANSFER_ENCODING, nil
+        header Grape::Http::Headers::CACHE_CONTROL, 'no-cache' # Skips ETag generation (reading the response up front)
         if value.is_a?(String)
           file_body = Grape::ServeStream::FileBody.new(value)
           @stream = Grape::ServeStream::StreamResponse.new(file_body)

lib/grape/endpoint.rb

@@ -250,7 +250,7 @@ def run
           if (allowed_methods = env[Grape::Env::GRAPE_ALLOWED_METHODS])
             raise Grape::Exceptions::MethodNotAllowed.new(header.merge('Allow' => allowed_methods)) unless options?
 
-            header 'Allow', allowed_methods
+            header Grape::Http::Headers::ALLOW, allowed_methods
             response_object = ''
             status 204
           else

lib/grape/http/headers.rb

@@ -10,7 +10,24 @@ module Headers
       PATH_INFO       = 'PATH_INFO'
       REQUEST_METHOD  = 'REQUEST_METHOD'
       QUERY_STRING    = 'QUERY_STRING'
-      CONTENT_TYPE    = 'Content-Type'
+
+      if Grape.rack3?
+        ALLOW             = 'allow'
+        CACHE_CONTROL     = 'cache-control'
+        CONTENT_LENGTH    = 'content-length'
+        CONTENT_TYPE      = 'content-type'
+        LOCATION          = 'location'
+        TRANSFER_ENCODING = 'transfer-encoding'
+        X_CASCADE         = 'x-cascade'
+      else
+        ALLOW             = 'Allow'
+        CACHE_CONTROL     = 'Cache-Control'
+        CONTENT_LENGTH    = 'Content-Length'
+        CONTENT_TYPE      = 'Content-Type'
+        LOCATION          = 'Location'
+        TRANSFER_ENCODING = 'Transfer-Encoding'
+        X_CASCADE         = 'X-Cascade'
+      end
 
       GET     = 'GET'
       POST    = 'POST'
@@ -24,7 +41,6 @@ module Headers
       SUPPORTED_METHODS_WITHOUT_OPTIONS = Grape::Util::LazyObject.new { [GET, POST, PUT, PATCH, DELETE, HEAD].freeze }
 
       HTTP_ACCEPT_VERSION    = 'HTTP_ACCEPT_VERSION'
-      X_CASCADE              = 'X-Cascade'
       HTTP_TRANSFER_ENCODING = 'HTTP_TRANSFER_ENCODING'
       HTTP_ACCEPT            = 'HTTP_ACCEPT'
 

lib/grape/request.rb

@@ -46,8 +46,14 @@ def build_headers
       end
     end
 
-    def transform_header(header)
-      -header[5..].split('_').each(&:capitalize!).join('-')
+    if Grape.rack3?
+      def transform_header(header)
+        -header[5..].tr('_', '-').downcase
+      end
+    else
+      def transform_header(header)
+        -header[5..].split('_').map(&:capitalize).join('-')
+      end
     end
   end
 end

lib/grape/version.rb

@@ -2,5 +2,5 @@
 
 module Grape
   # The current version of Grape.
-  VERSION = '1.8.1'
+  VERSION = '1.9.0'
 end

spec/grape/api/custom_validations_spec.rb

@@ -162,13 +162,19 @@ def validate(request)
           return unless request.params.key? @attrs.first
           # check if admin flag is set to true
           return unless @option
+
           # check if user is admin or not
           # as an example get a token from request and check if it's admin or not
-          raise Grape::Exceptions::Validation.new(params: @attrs, message: 'Can not set Admin only field.') unless request.headers['X-Access-Token'] == 'admin'
+          raise Grape::Exceptions::Validation.new(params: @attrs, message: 'Can not set Admin only field.') unless request.headers[access_header] == 'admin'
+        end
+
+        def access_header
+          Grape.rack3? ? 'x-access-token' : 'X-Access-Token'
         end
       end
     end
     let(:app) { Rack::Builder.new(subject) }
+    let(:x_access_token_header) { Grape.rack3? ? 'x-access-token' : 'X-Access-Token' }
 
     before do
       described_class.register_validator('admin', admin_validator)
@@ -197,14 +203,14 @@ def validate(request)
     end
 
     it 'does not fail when we send admin fields and we are admin' do
-      header 'X-Access-Token', 'admin'
+      header x_access_token_header, 'admin'
       get '/', admin_field: 'tester', non_admin_field: 'toaster', admin_false_field: 'test'
       expect(last_response.status).to eq 200
       expect(last_response.body).to eq 'bacon'
     end
 
     it 'fails when we send admin fields and we are not admin' do
-      header 'X-Access-Token', 'user'
+      header x_access_token_header, 'user'
       get '/', admin_field: 'tester', non_admin_field: 'toaster', admin_false_field: 'test'
       expect(last_response.status).to eq 400
       expect(last_response.body).to include 'Can not set Admin only field.'