introducing the :no_proxy option

can be passed in the `:proxy` option hash, and receives domains, as
strings, which requests should not go through the proxy.

Gemfile

@@ -18,7 +18,11 @@ group :test do
   gem "ruby-ntlm"
   gem "sentry-ruby" if RUBY_VERSION >= "2.4"
   gem "spy"
-  gem "webmock"
+  if RUBY_VERSION < "2.3.0"
+    gem "webmock", "< 3.15.0"
+  else
+    gem "webmock"
+  end
   gem "websocket-driver"
 
   gem "net-ssh", "~> 4.2.0" if RUBY_VERSION < "2.2"
@@ -115,8 +119,8 @@ group :assorted do
     if RUBY_VERSION < "2.2"
       gem "pry-byebug", "~> 3.4.3"
     else
-      gem "pry-byebug"
       gem "debug" if RUBY_VERSION >= "3.1.0"
+      gem "pry-byebug"
     end
   end
 end

docker-compose.yml

@@ -3,6 +3,7 @@ services:
   httpx:
     environment:
       - HTTPBIN_HOST=nghttp2
+      - HTTPBIN_NO_PROXY_HOST=http://httpbin:8000
       - HTTPX_HTTP_PROXY=http://proxyuser:password@httpproxy:3128
       - HTTPX_HTTPS_PROXY=http://proxyuser:password@httpproxy:3128
       - HTTPX_HTTP2_PROXY=http://proxyuser:password@http2proxy:80

lib/httpx/plugins/proxy.rb

@@ -105,6 +105,10 @@ module HTTPX
           end
           return if @_proxy_uris.empty?
 
+          proxy = options.proxy
+
+          return { uri: uri.host } if proxy && proxy.key?(:no_proxy) && !Array(proxy[:no_proxy]).grep(uri.host).empty?
+
           proxy_opts = { uri: @_proxy_uris.first }
           proxy_opts = options.proxy.merge(proxy_opts) if options.proxy
           proxy_opts
@@ -117,7 +121,9 @@ module HTTPX
           next_proxy = proxy_uris(uri, options)
           raise Error, "Failed to connect to proxy" unless next_proxy
 
-          proxy_options = options.merge(proxy: Parameters.new(**next_proxy))
+          proxy = Parameters.new(**next_proxy) unless next_proxy[:uri] == uri.host
+
+          proxy_options = options.merge(proxy: proxy)
           connection = pool.find_connection(uri, proxy_options) || build_connection(uri, proxy_options)
           unless connections.nil? || connections.include?(connection)
             connections << connection

sig/plugins/proxy.rbs

@@ -21,7 +21,7 @@ module HTTPX
 
         private
 
-        def initialize: (uri: generic_uri, ?scheme: String, ?username: String, ?password: String, **extra) -> untyped
+        def initialize: (uri: generic_uri, ?scheme: String, ?username: String, ?password: String, **untyped) -> untyped
       end
 
       def self.configure: (singleton(Session)) -> void

test/support/http_helpers.rb

@@ -21,4 +21,8 @@ module HTTPHelpers
   def httpbin
     ENV.fetch("HTTPBIN_HOST", "nghttp2.org/httpbin")
   end
+
+  def httpbin_no_proxy
+    URI(ENV.fetch("HTTPBIN_NO_PROXY_HOST", "httpbin.org"))
+  end
 end

test/support/proxy_response_detector.rb

@@ -17,7 +17,7 @@ module ProxyResponseDetector
 
   module ConnectionMethods
     def send(request)
-      return super unless @options.respond_to?(:proxy)
+      return super unless @options.respond_to?(:proxy) && @options.proxy
 
       proxy_uri = URI(@options.proxy.uri)
 

test/support/requests/plugins/proxy.rb

@@ -16,7 +16,7 @@ module Requests
         assert_raises(HTTPX::HTTPProxyError) { session.get(uri) }
       end
 
-      def test_plugin_http_http1_proxy
+      def test_plugin_http_http_proxy
         return unless origin.start_with?("http://")
 
         session = HTTPX.plugin(:proxy, fallback_protocol: "http/1.1").plugin(ProxyResponseDetector).with_proxy(uri: http_proxy)
@@ -27,6 +27,26 @@ module Requests
         assert response.proxied?
       end
 
+      def test_plugin_http_no_proxy
+        return unless origin.start_with?("http://")
+
+        session = HTTPX.plugin(:proxy).plugin(ProxyResponseDetector).with_proxy(uri: http_proxy, no_proxy: [httpbin_no_proxy.host])
+
+        # proxy
+        uri = build_uri("/get")
+        response = session.get(uri)
+        verify_status(response, 200)
+        verify_body_length(response)
+        assert response.proxied?
+
+        # no proxy
+        no_proxy_uri = build_uri("/get", httpbin_no_proxy)
+        no_proxy_response = session.get(no_proxy_uri)
+        verify_status(no_proxy_response, 200)
+        verify_body_length(no_proxy_response)
+        assert !no_proxy_response.proxied?
+      end
+
       def test_plugin_http_h2_proxy
         return unless origin.start_with?("http://")
 
@@ -99,11 +119,10 @@ module Requests
         no_auth_proxy.user = nil
         no_auth_proxy.password = nil
 
-        session = HTTPX.plugin(:proxy).plugin(ProxyResponseDetector).with_proxy(uri: no_auth_proxy.to_s)
+        session = HTTPX.plugin(:proxy).with_proxy(uri: no_auth_proxy.to_s)
         uri = build_uri("/get")
         response = session.get(uri)
         verify_status(response, 407)
-        assert response.proxied?
       end
 
       def test_plugin_http_proxy_digest_auth
@@ -228,7 +247,6 @@ module Requests
 
       def test_plugin_ssh_proxy
         session = HTTPX.plugin(:"proxy/ssh")
-                       .plugin(ProxyResponseDetector)
                        .with_proxy(uri: ssh_proxy,
                                    username: "root",
                                    auth_methods: %w[publickey],
@@ -238,7 +256,6 @@ module Requests
         response = session.get(uri)
         verify_status(response, 200)
         verify_body_length(response)
-        assert response.proxied?
       end if ENV.key?("HTTPX_SSH_PROXY") && RUBY_ENGINE != "jruby"
     end
   end