Refactor AutoInflate/Deflate into generic features

This makes HTTP::Client, Request and Response unaware of the
implementation details behind inflating and deflating stream bodies.
Instead, the client iterates over all enabled features on request and
response, calling `#wrap_request` or `#wrap_response`, which is expected
to return the Request or Response as-is if nothing should be done, or
returns a new Request or Response object after having done whatever
transformation the feature requires.

lib/http/client.rb

@@ -43,14 +43,17 @@ def build_request(verb, uri, opts = {}) # rubocop:disable Style/OptionHash
       body    = make_request_body(opts, headers)
       proxy   = opts.proxy
 
-      HTTP::Request.new(
+      req = HTTP::Request.new(
         :verb         => verb,
         :uri          => uri,
         :headers      => headers,
         :proxy        => proxy,
-        :body         => body,
-        :auto_deflate => opts.feature(:auto_deflate)
+        :body         => body
       )
+
+      opts.features.inject(req) do |request, (_name, feature)|
+        feature.wrap_request(request)
+      end
     end
 
     # @!method persistent?
@@ -78,10 +81,13 @@ def perform(req, options)
         :proxy_headers => @connection.proxy_response_headers,
         :connection    => @connection,
         :encoding      => options.encoding,
-        :auto_inflate  => options.feature(:auto_inflate),
         :uri           => req.uri
       )
 
+      res = options.features.inject(res) do |response, (_name, feature)|
+        feature.wrap_response(response)
+      end
+
       @connection.finish_response if req.verb == :head
       @state = :clean
 

lib/http/feature.rb

@@ -5,5 +5,13 @@ class Feature
     def initialize(opts = {}) # rubocop:disable Style/OptionHash
       @opts = opts
     end
+
+    def wrap_request(request)
+      request
+    end
+
+    def wrap_response(response)
+      response
+    end
   end
 end

lib/http/features/auto_deflate.rb

@@ -16,6 +16,19 @@ def initialize(*)
         raise Error, "Only gzip and deflate methods are supported" unless %w[gzip deflate].include?(@method)
       end
 
+      def wrap_request(request)
+        return request unless method
+
+        Request.new(
+          :version => request.version,
+          :verb => request.verb,
+          :uri => request.uri,
+          :headers => request.headers,
+          :proxy => request.proxy,
+          :body => deflated_body(request.body)
+        )
+      end
+
       def deflated_body(body)
         case method
         when "gzip"
@@ -36,6 +49,11 @@ def size
           @compressed.size
         end
 
+        def read(*a)
+          compress_all! unless @compressed
+          @compressed.read(*a)
+        end
+
         def each(&block)
           return to_enum __method__ unless block
 

lib/http/features/auto_inflate.rb

@@ -3,12 +3,20 @@
 module HTTP
   module Features
     class AutoInflate < Feature
-      def stream_for(connection, response)
-        if %w[deflate gzip x-gzip].include?(response.headers[:content_encoding])
-          Response::Inflater.new(connection)
-        else
-          connection
-        end
+      def wrap_response(response)
+        return response unless %w[deflate gzip x-gzip].include?(response.headers[:content_encoding])
+        Response.new(
+          :status => response.status,
+          :version => response.version,
+          :headers => response.headers,
+          :proxy_headers => response.proxy_headers,
+          :connection => response.connection,
+          :body => stream_for(response.connection)
+        )
+      end
+
+      def stream_for(connection)
+        Response::Body.new(Response::Inflater.new(connection))
       end
     end
   end

lib/http/request.rb

@@ -87,7 +87,6 @@ def initialize(opts)
 
       @proxy   = opts[:proxy] || {}
       @body    = Request::Body.new(opts[:body])
-      @deflate = opts[:auto_deflate]
       @version = opts[:version] || "1.1"
       @headers = HTTP::Headers.coerce(opts[:headers] || {})
 
@@ -106,15 +105,13 @@ def redirect(uri, verb = @verb)
         :headers      => headers,
         :proxy        => proxy,
         :body         => body.source,
-        :auto_deflate => @deflate,
         :version      => version
       )
     end
 
     # Stream the request to a socket
     def stream(socket)
       include_proxy_headers if using_proxy? && !@uri.https?
-      body = @deflate ? @deflate.deflated_body(self.body) : self.body
       Request::Writer.new(socket, body, headers, headline).stream
     end
 

lib/http/response.rb

@@ -20,6 +20,9 @@ class Response
     # @return [Status]
     attr_reader :status
 
+    # @return [String]
+    attr_reader :version
+
     # @return [Body]
     attr_reader :body
 
@@ -46,14 +49,13 @@ def initialize(opts)
       @headers       = HTTP::Headers.coerce(opts[:headers] || {})
       @proxy_headers = HTTP::Headers.coerce(opts[:proxy_headers] || {})
 
-      if opts.include?(:connection)
+      if opts.include?(:body)
+        @body = opts.fetch(:body)
+      else
         connection = opts.fetch(:connection)
         encoding   = opts[:encoding] || charset || Encoding::BINARY
-        stream     = body_stream_for(connection, opts)
 
-        @body = Response::Body.new(stream, :encoding => encoding)
-      else
-        @body = opts.fetch(:body)
+        @body = Response::Body.new(connection, :encoding => encoding)
       end
     end
 
@@ -160,15 +162,5 @@ def parse(as = nil)
     def inspect
       "#<#{self.class}/#{@version} #{code} #{reason} #{headers.to_h.inspect}>"
     end
-
-    private
-
-    def body_stream_for(connection, opts)
-      if opts[:auto_inflate]
-        opts[:auto_inflate].stream_for(connection, self)
-      else
-        connection
-      end
-    end
   end
 end

spec/lib/http/features/auto_inflate_spec.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 RSpec.describe HTTP::Features::AutoInflate do
-  subject { HTTP::Features::AutoInflate.new }
+  subject(:feature) { HTTP::Features::AutoInflate.new }
   let(:connection) { double }
   let(:headers) { {} }
   let(:response) do
@@ -13,56 +13,52 @@
     )
   end
 
-  describe "stream_for" do
+  describe "wrap_response" do
+    subject(:result) { feature.wrap_response(response) }
+
     context "when there is no Content-Encoding header" do
-      it "returns connection" do
-        stream = subject.stream_for(connection, response)
-        expect(stream).to eq(connection)
+      it "returns original request" do
+        expect(result).to be response
       end
     end
 
     context "for identity Content-Encoding header" do
-      let(:headers) { {:content_encoding => "not-supported"} }
+      let(:headers) { {:content_encoding => "identity"} }
 
-      it "returns connection" do
-        stream = subject.stream_for(connection, response)
-        expect(stream).to eq(connection)
+      it "returns original request" do
+        expect(result).to be response
       end
     end
 
     context "for unknown Content-Encoding header" do
       let(:headers) { {:content_encoding => "not-supported"} }
 
-      it "returns connection" do
-        stream = subject.stream_for(connection, response)
-        expect(stream).to eq(connection)
+      it "returns original request" do
+        expect(result).to be response
       end
     end
 
     context "for deflate Content-Encoding header" do
       let(:headers) { {:content_encoding => "deflate"} }
 
-      it "returns HTTP::Response::Inflater instance - connection wrapper" do
-        stream = subject.stream_for(connection, response)
-        expect(stream).to be_instance_of HTTP::Response::Inflater
+      it "returns a HTTP::Response wrapping the inflated response body" do
+        expect(result.body).to be_instance_of HTTP::Response::Body
       end
     end
 
     context "for gzip Content-Encoding header" do
       let(:headers) { {:content_encoding => "gzip"} }
 
-      it "returns HTTP::Response::Inflater instance - connection wrapper" do
-        stream = subject.stream_for(connection, response)
-        expect(stream).to be_instance_of HTTP::Response::Inflater
+      it "returns a HTTP::Response wrapping the inflated response body" do
+        expect(result.body).to be_instance_of HTTP::Response::Body
       end
     end
 
     context "for x-gzip Content-Encoding header" do
       let(:headers) { {:content_encoding => "x-gzip"} }
 
-      it "returns HTTP::Response::Inflater instance - connection wrapper" do
-        stream = subject.stream_for(connection, response)
-        expect(stream).to be_instance_of HTTP::Response::Inflater
+      it "returns a HTTP::Response wrapping the inflated response body" do
+        expect(result.body).to be_instance_of HTTP::Response::Body
       end
     end
   end