Revisit versioner middlewares (#2484)

* AcceptHeaderHandler is now part of Grape::Middleware::Versioner::Header
Use `const_get` to find versioner
Grape::Middleware::Versioner::* uses `default_options` like other middlewares
Add versioner_helpers for Grape::Middleware::Versioner::*
Replace `merge` by `deep_merge` in Grape::Middleware::Base initialize
Add specs

* Add CHANGELOG entry

* Remove prefix throw_ and add!
Use `camelize` instead of `classify`

CHANGELOG.md

@@ -3,6 +3,7 @@
 #### Features
 
 * [#2475](https://github.com/ruby-grape/grape/pull/2475): Remove Grape::Util::Registrable - [@ericproulx](https://github.com/ericproulx).
+* [#2484](https://github.com/ruby-grape/grape/pull/2484): Refactor versioner middlewares - [@ericproulx](https://github.com/ericproulx).
 * Your contribution here.
 
 #### Fixes

lib/grape/endpoint.rb

@@ -191,8 +191,7 @@ def prepare_default_route_attributes
 
     def prepare_version
       version = namespace_inheritable(:version)
-      return unless version
-      return if version.empty?
+      return if version.blank?
 
       version.length == 1 ? version.first : version
     end
@@ -298,9 +297,9 @@ def build_stack(helpers)
 
       stack.concat namespace_stackable(:middleware)
 
-      if namespace_inheritable(:version)
+      if namespace_inheritable(:version).present?
         stack.use Grape::Middleware::Versioner.using(namespace_inheritable(:version_options)[:using]),
-                  versions: namespace_inheritable(:version)&.flatten,
+                  versions: namespace_inheritable(:version).flatten,
                   version_options: namespace_inheritable(:version_options),
                   prefix: namespace_inheritable(:root_prefix),
                   mount_path: namespace_stackable(:mount_path).first

lib/grape/middleware/base.rb

@@ -4,18 +4,17 @@ module Grape
   module Middleware
     class Base
       include Helpers
+      include Grape::DSL::Headers
 
       attr_reader :app, :env, :options
 
       TEXT_HTML = 'text/html'
 
-      include Grape::DSL::Headers
-
       # @param [Rack Application] app The standard argument for a Rack middleware.
       # @param [Hash] options A hash of options, simply stored for use by subclasses.
       def initialize(app, *options)
         @app = app
-        @options = options.any? ? default_options.merge(options.shift) : default_options
+        @options = options.any? ? default_options.deep_merge(options.shift) : default_options
         @app_response = nil
       end
 

lib/grape/middleware/versioner.rb

@@ -4,30 +4,21 @@
 # on the requests. The current methods for determining version are:
 #
 #   :header - version from HTTP Accept header.
+#   :accept_version_header - version from HTTP Accept-Version header
 #   :path   - version from uri. e.g. /v1/resource
 #   :param  - version from uri query string, e.g. /v1/resource?apiver=v1
-#
 # See individual classes for details.
 module Grape
   module Middleware
     module Versioner
       module_function
 
-      # @param strategy [Symbol] :path, :header or :param
+      # @param strategy [Symbol] :path, :header, :accept_version_header or :param
       # @return a middleware class based on strategy
       def using(strategy)
-        case strategy
-        when :path
-          Path
-        when :header
-          Header
-        when :param
-          Param
-        when :accept_version_header
-          AcceptVersionHeader
-        else
-          raise Grape::Exceptions::InvalidVersionerOption.new(strategy)
-        end
+        Grape::Middleware::Versioner.const_get(:"#{strategy.to_s.camelize}")
+      rescue NameError
+        raise Grape::Exceptions::InvalidVersionerOption, strategy
       end
     end
   end

lib/grape/middleware/versioner/accept_version_header.rb

@@ -17,45 +17,22 @@ module Versioner
       # X-Cascade header to alert Grape::Router to attempt the next matched
       # route.
       class AcceptVersionHeader < Base
-        def before
-          potential_version = (env[Grape::Http::Headers::HTTP_ACCEPT_VERSION] || '').strip
-
-          if strict? && potential_version.empty?
-            # If no Accept-Version header:
-            throw :error, status: 406, headers: error_headers, message: 'Accept-Version header must be set.'
-          end
+        include VersionerHelpers
 
-          return if potential_version.empty?
+        def before
+          potential_version = env[Grape::Http::Headers::HTTP_ACCEPT_VERSION]&.strip
+          not_acceptable!('Accept-Version header must be set.') if strict? && potential_version.blank?
 
-          # If the requested version is not supported:
-          throw :error, status: 406, headers: error_headers, message: 'The requested version is not supported.' unless versions.any? { |v| v.to_s == potential_version }
+          return if potential_version.blank?
 
+          not_acceptable!('The requested version is not supported.') unless potential_version_match?(potential_version)
           env[Grape::Env::API_VERSION] = potential_version
         end
 
         private
 
-        def versions
-          options[:versions] || []
-        end
-
-        def strict?
-          options[:version_options] && options[:version_options][:strict]
-        end
-
-        # By default those errors contain an `X-Cascade` header set to `pass`, which allows nesting and stacking
-        # of routes (see Grape::Router) for more information). To prevent
-        # this behavior, and not add the `X-Cascade` header, one can set the `:cascade` option to `false`.
-        def cascade?
-          if options[:version_options]&.key?(:cascade)
-            options[:version_options][:cascade]
-          else
-            true
-          end
-        end
-
-        def error_headers
-          cascade? ? { Grape::Http::Headers::X_CASCADE => 'pass' } : {}
+        def not_acceptable!(message)
+          throw :error, status: 406, headers: error_headers, message: message
         end
       end
     end

lib/grape/middleware/versioner/header.rb

@@ -22,17 +22,10 @@ module Versioner
       # X-Cascade header to alert Grape::Router to attempt the next matched
       # route.
       class Header < Base
+        include VersionerHelpers
+
         def before
-          handler = Grape::Util::AcceptHeaderHandler.new(
-            accept_header: env[Grape::Http::Headers::HTTP_ACCEPT],
-            versions: options[:versions],
-            **options.fetch(:version_options) { {} }
-          )
-
-          handler.match_best_quality_media_type!(
-            content_types: content_types,
-            allowed_methods: env[Grape::Env::GRAPE_ALLOWED_METHODS]
-          ) do |media_type|
+          match_best_quality_media_type! do |media_type|
             env.update(
               Grape::Env::API_TYPE => media_type.type,
               Grape::Env::API_SUBTYPE => media_type.subtype,
@@ -42,6 +35,98 @@ def before
             )
           end
         end
+
+        private
+
+        def match_best_quality_media_type!
+          return unless vendor
+
+          strict_header_checks!
+          media_type = Grape::Util::MediaType.best_quality(accept_header, available_media_types)
+          if media_type
+            yield media_type
+          else
+            fail!(allowed_methods)
+          end
+        end
+
+        def allowed_methods
+          env[Grape::Env::GRAPE_ALLOWED_METHODS]
+        end
+
+        def accept_header
+          env[Grape::Http::Headers::HTTP_ACCEPT]
+        end
+
+        def strict_header_checks!
+          return unless strict?
+
+          accept_header_check!
+          version_and_vendor_check!
+        end
+
+        def accept_header_check!
+          return if accept_header.present?
+
+          invalid_accept_header!('Accept header must be set.')
+        end
+
+        def version_and_vendor_check!
+          return if versions.blank? || version_and_vendor?
+
+          invalid_accept_header!('API vendor or version not found.')
+        end
+
+        def q_values_mime_types
+          @q_values_mime_types ||= Rack::Utils.q_values(accept_header).map(&:first)
+        end
+
+        def version_and_vendor?
+          q_values_mime_types.any? { |mime_type| Grape::Util::MediaType.match?(mime_type) }
+        end
+
+        def invalid_accept_header!(message)
+          raise Grape::Exceptions::InvalidAcceptHeader.new(message, error_headers)
+        end
+
+        def invalid_version_header!(message)
+          raise Grape::Exceptions::InvalidVersionHeader.new(message, error_headers)
+        end
+
+        def fail!(grape_allowed_methods)
+          return grape_allowed_methods if grape_allowed_methods.present?
+
+          media_types = q_values_mime_types.map { |mime_type| Grape::Util::MediaType.parse(mime_type) }
+          vendor_not_found!(media_types) || version_not_found!(media_types)
+        end
+
+        def vendor_not_found!(media_types)
+          return unless media_types.all? { |media_type| media_type&.vendor && media_type.vendor != vendor }
+
+          invalid_accept_header!('API vendor not found.')
+        end
+
+        def version_not_found!(media_types)
+          return unless media_types.all? { |media_type| media_type&.version && versions&.exclude?(media_type.version) }
+
+          invalid_version_header!('API version not found.')
+        end
+
+        def available_media_types
+          [].tap do |available_media_types|
+            base_media_type = "application/vnd.#{vendor}"
+            content_types.each_key do |extension|
+              versions&.reverse_each do |version|
+                available_media_types << "#{base_media_type}-#{version}+#{extension}"
+                available_media_types << "#{base_media_type}-#{version}"
+              end
+              available_media_types << "#{base_media_type}+#{extension}"
+            end
+
+            available_media_types << base_media_type
+            available_media_types.concat(content_types.values.flatten)
+          end
+        end
       end
     end
   end

lib/grape/middleware/versioner/param.rb

@@ -19,31 +19,15 @@ module Versioner
       #
       #   env['api.version'] => 'v1'
       class Param < Base
-        def default_options
-          {
-            version_options: {
-              parameter: 'apiver'
-            }
-          }
-        end
+        include VersionerHelpers
 
         def before
-          potential_version = Rack::Utils.parse_nested_query(env[Rack::QUERY_STRING])[paramkey]
-          return if potential_version.nil?
+          potential_version = Rack::Utils.parse_nested_query(env[Rack::QUERY_STRING])[parameter_key]
+          return if potential_version.blank?
 
-          throw :error, status: 404, message: '404 API Version Not Found', headers: { Grape::Http::Headers::X_CASCADE => 'pass' } if options[:versions] && !options[:versions].find { |v| v.to_s == potential_version }
+          version_not_found! unless potential_version_match?(potential_version)
           env[Grape::Env::API_VERSION] = potential_version
-          env[Rack::RACK_REQUEST_QUERY_HASH].delete(paramkey) if env.key? Rack::RACK_REQUEST_QUERY_HASH
-        end
-
-        private
-
-        def paramkey
-          version_options[:parameter] || default_options[:version_options][:parameter]
-        end
-
-        def version_options
-          options[:version_options]
+          env[Rack::RACK_REQUEST_QUERY_HASH].delete(parameter_key) if env.key? Rack::RACK_REQUEST_QUERY_HASH
         end
       end
     end

lib/grape/middleware/versioner/path.rb

@@ -17,44 +17,24 @@ module Versioner
       #   env['api.version'] => 'v1'
       #
       class Path < Base
-        def default_options
-          {
-            pattern: /.*/i
-          }
-        end
+        include VersionerHelpers
 
         def before
-          path = env[Rack::PATH_INFO].dup
-          path.sub!(mount_path, '') if mounted_path?(path)
+          path_info = Grape::Router.normalize_path(env[Rack::PATH_INFO])
+          return if path_info == '/'
 
-          if prefix && path.index(prefix) == 0 # rubocop:disable all
-            path.sub!(prefix, '')
-            path = Grape::Router.normalize_path(path)
+          [mount_path, Grape::Router.normalize_path(prefix)].each do |path|
+            path_info.delete_prefix!(path) if path.present? && path != '/' && path_info.start_with?(path)
           end
 
-          pieces = path.split('/')
-          potential_version = pieces[1]
-          return unless potential_version&.match?(options[:pattern])
-
-          throw :error, status: 404, message: '404 API Version Not Found' if options[:versions] && !options[:versions].find { |v| v.to_s == potential_version }
-          env[Grape::Env::API_VERSION] = potential_version
-        end
-
-        private
+          slash_position = path_info.index('/', 1) # omit the first one
+          return unless slash_position
 
-        def mounted_path?(path)
-          return false unless mount_path && path.start_with?(mount_path)
+          potential_version = path_info[1..slash_position - 1]
+          return unless potential_version.match?(pattern)
 
-          rest = path.slice(mount_path.length..-1)
-          rest.start_with?('/') || rest.empty?
-        end
-
-        def mount_path
-          @mount_path ||= options[:mount_path] && options[:mount_path] != '/' ? options[:mount_path] : ''
-        end
-
-        def prefix
-          Grape::Router.normalize_path(options[:prefix].to_s) if options[:prefix]
+          version_not_found! unless potential_version_match?(potential_version)
+          env[Grape::Env::API_VERSION] = potential_version
         end
       end
     end