Added multipart plugin, to handle multipart requests

This logic was extracted from the vanilla httpx build to a plugin to
make the gem "leaner", by removing "http_form_data" as a hard
dependency.

The multipart plugin still requires one to install it though, but if you
don't need to upload files, you don't have to install the gem anymore

httpx.gemspec

@@ -20,8 +20,7 @@ Gem::Specification.new do |gem|
   gem.require_paths = ["lib"]
   gem.version       = HTTPX::VERSION
 
-  gem.add_runtime_dependency "http-2",          ">= 0.9.0"
-  gem.add_runtime_dependency "http-form_data",  ">= 2.0.0", "< 3"
-
-  gem.add_development_dependency "http-cookie", "~> 1.0"
+  gem.add_runtime_dependency "http-2",              ">= 0.9.0"
+  gem.add_development_dependency "http-form_data",  ">= 2.0.0", "< 3"
+  gem.add_development_dependency "http-cookie",     "~> 1.0"
 end

lib/httpx/plugins/multipart.rb

@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+module HTTPX
+  module Plugins
+    module Multipart
+      module FormTranscoder
+        module_function
+
+        class Encoder
+          extend Forwardable
+
+          def_delegator :@raw, :content_type
+
+          def_delegator :@raw, :to_s
+
+          def_delegator :@raw, :read
+
+          def initialize(form)
+            @raw = HTTP::FormData.create(form)
+          end
+
+          def bytesize
+            @raw.content_length
+          end
+
+          def force_encoding(*args)
+            @raw.to_s.force_encoding(*args)
+          end
+
+          def to_str
+            @raw.to_s
+          end
+        end
+
+        def encode(form)
+          Encoder.new(form)
+        end
+      end
+
+      def self.load_dependencies(*)
+        require "http/form_data"
+      end
+
+      def self.configure(*)
+        Transcoder.register("form", FormTranscoder)
+      end
+    end
+    register_plugin :multipart, Multipart
+  end
+end

lib/httpx/transcoder/form.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "forwardable"
-require "http/form_data"
+require "uri"
 
 module HTTPX::Transcoder
   module Form
@@ -10,22 +10,18 @@ module HTTPX::Transcoder
     class Encoder
       extend Forwardable
 
-      def_delegator :@raw, :content_type
-
       def_delegator :@raw, :to_s
 
-      def_delegator :@raw, :read
+      def_delegator :@raw, :bytesize
+
+      def_delegator :@raw, :force_encoding
 
       def initialize(form)
-        @raw = HTTP::FormData.create(form)
+        @raw = URI.encode_www_form(form)
       end
 
-      def bytesize
-        @raw.content_length
-      end
-
-      def force_encoding(*args)
-        @raw.to_s.force_encoding(*args)
+      def content_type
+        "application/x-www-form-urlencoded"
       end
 
       def to_str

test/http_test.rb

@@ -23,6 +23,7 @@ class HTTPTest < Minitest::Test
   include Plugins::Compression
   include Plugins::H2C
   include Plugins::Retries
+  include Plugins::Multipart
 
   private
 

test/https_test.rb

@@ -21,6 +21,7 @@ class HTTPSTest < Minitest::Test
   include Plugins::Compression
   include Plugins::PushPromise if OpenSSL::SSL::SSLContext.instance_methods.include?(:alpn_protocols)
   include Plugins::Retries
+  include Plugins::Multipart
 
   private
 

test/support/requests/plugins/multipart.rb

@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+require "http/form_data"
+
+module Requests
+  module Plugins
+    module Multipart
+      %w[post put patch delete].each do |meth|
+        define_method :"test_plugin_multipart_urlencoded_#{meth}" do
+          uri = build_uri("/#{meth}")
+          response = HTTPX.plugin(:multipart)
+                          .send(meth, uri, form: { "foo" => "bar" })
+          verify_status(response, 200)
+          body = json_body(response)
+          verify_header(body["headers"], "Content-Type", "application/x-www-form-urlencoded")
+          verify_uploaded(body, "form", "foo" => "bar")
+        end
+
+        define_method :"test_plugin_multipart_formdata_#{meth}" do
+          uri = build_uri("/#{meth}")
+          response = HTTPX.plugin(:multipart)
+                          .send(meth, uri, form: { image: HTTP::FormData::File.new(fixture_file_path) })
+          verify_status(response, 200)
+          body = json_body(response)
+          verify_header(body["headers"], "Content-Type", "multipart/form-data")
+          verify_uploaded_image(body)
+        end
+      end
+
+      def fixture
+        File.read(fixture_file_path, encoding: Encoding::BINARY)
+      end
+
+      def fixture_name
+        File.basename(fixture_file_path)
+      end
+
+      def fixture_file_path
+        File.join("test", "support", "fixtures", "image.jpg")
+      end
+
+      def verify_uploaded_image(body)
+        assert body.key?("files"), "there were no files uploaded"
+        assert body["files"].key?("image"), "there is no image in the file"
+      end
+    end
+  end
+end

test/support/requests/with_body.rb

@@ -21,6 +21,17 @@ module Requests
         verify_uploaded(body, "form", "foo" => "bar")
       end
 
+      define_method :"test_#{meth}_expect_100_form_params" do
+        uri = build_uri("/#{meth}")
+        response = HTTPX.headers("expect" => "100-continue")
+                        .send(meth, uri, form: { "foo" => "bar" })
+        verify_status(response, 200)
+        body = json_body(response)
+        verify_header(body["headers"], "Content-Type", "application/x-www-form-urlencoded")
+        verify_header(body["headers"], "Expect", "100-continue")
+        verify_uploaded(body, "form", "foo" => "bar")
+      end
+
       define_method :"test_#{meth}_json_params" do
         uri = build_uri("/#{meth}")
         response = HTTPX.send(meth, uri, json: { "foo" => "bar" })
@@ -73,50 +84,13 @@ module Requests
         verify_header(body["headers"], "Content-Type", "application/octet-stream")
         verify_uploaded(body, "data", "data")
       end
-
-      define_method :"test_#{meth}_form_file_params" do
-        uri = build_uri("/#{meth}")
-        response = HTTPX.send(meth, uri, form: { image: HTTP::FormData::File.new(fixture_file_path) })
-        verify_status(response, 200)
-        body = json_body(response)
-        verify_header(body["headers"], "Content-Type", "multipart/form-data")
-        verify_uploaded_image(body)
-      end
-
-      define_method :"test_#{meth}_expect_100_form_file_params" do
-        uri = build_uri("/#{meth}")
-        response = HTTPX.headers("expect" => "100-continue")
-                        .send(meth, uri, form: { image: HTTP::FormData::File.new(fixture_file_path) })
-        verify_status(response, 200)
-        body = json_body(response)
-        verify_header(body["headers"], "Content-Type", "multipart/form-data")
-        verify_header(body["headers"], "Expect", "100-continue")
-        verify_uploaded_image(body)
-      end
     end
 
     private
 
-    def fixture
-      File.read(fixture_file_path, encoding: Encoding::BINARY)
-    end
-
-    def fixture_name
-      File.basename(fixture_file_path)
-    end
-
-    def fixture_file_path
-      File.join("test", "support", "fixtures", "image.jpg")
-    end
-
     def verify_uploaded(body, type, expect)
       assert body.key?(type), "there is no #{type} available"
       assert body[type] == expect, "#{type} is unexpected: #{body[type]} (expected: #{expect})"
     end
-
-    def verify_uploaded_image(body)
-      assert body.key?("files"), "there were no files uploaded"
-      assert body["files"].key?("image"), "there is no image in the file"
-    end
   end
 end