add integration tests for HTTP proxy support

Spins up a proxy server in a separate process, runs a few requests
through it with each adapter to verify that both proxy support and basic
authentication take effect.

lib/faraday/response/raise_error.rb

@@ -6,6 +6,9 @@ module Faraday
       case env[:status]
       when 404
         raise Faraday::Error::ResourceNotFound, response_values(env)
+      when 407
+        # mimic the behavior that we get with proxy requests with HTTPS
+        raise Faraday::Error::ConnectionFailed, %{407 "Proxy Authentication Required "}
       when ClientErrorStatuses
         raise Faraday::Error::ClientError, response_values(env)
       end

script/proxy-server

@@ -0,0 +1,41 @@
+#!/usr/bin/env ruby
+# Usage: script/proxy-server [-p PORT] [-u USER:PASSWORD]
+require 'webrick'
+require 'webrick/httpproxy'
+
+port = 4001
+
+if found = ARGV.index('-p')
+  port = ARGV[found + 1].to_i
+end
+if found = ARGV.index('-u')
+  username, password = ARGV[found + 1].split(':', 2)
+end
+
+match_credentials = lambda { |credentials|
+  got_username, got_password = credentials.to_s.unpack("m*")[0].split(":", 2)
+  got_username == username && got_password == password
+}
+
+log_io = $stdout
+log_io.sync = true
+
+webrick_opts = {
+  :Port => port, :Logger => WEBrick::Log::new(log_io),
+  :AccessLog => [[log_io, "[%{X-Faraday-Adapter}i] %m  %U  ->  %s %b"]],
+  :ProxyAuthProc => lambda { |req, res|
+    if username
+      type, credentials = req.header['proxy-authorization'].first.to_s.split(/\s+/, 2)
+      unless "Basic" == type && match_credentials.call(credentials)
+        raise WEBrick::HTTPStatus::ProxyAuthenticationRequired
+      end
+    end
+  }
+}
+
+proxy = WEBrick::HTTPProxyServer.new(webrick_opts)
+
+trap(:TERM) { proxy.shutdown }
+trap(:INT) { proxy.shutdown }
+
+proxy.start

script/test

@@ -24,6 +24,7 @@ if [[ "$RUBYOPT" != *"bundler/setup"* ]]; then
 fi
 
 port=3999
+proxy_port=3998
 scheme=http
 
 if [ "$SSL" = "yes" ]; then
@@ -51,8 +52,14 @@ start_server() {
   echo $!
 }
 
+start_proxy() {
+  mkdir -p log
+  script/proxy-server -p $proxy_port -u "faraday@test.local:there is cake" >log/proxy.log 2>&1 &
+  echo $!
+}
+
 server_started() {
-  lsof -i :$port >/dev/null
+  lsof -i :${1?} >/dev/null
 }
 
 timestamp() {
@@ -62,7 +69,7 @@ timestamp() {
 wait_for_server() {
   timeout=$(( `timestamp` + $1 ))
   while true; do
-    if server_started; then
+    if server_started "$2"; then
       break
     elif [ `timestamp` -gt "$timeout" ]; then
       echo "timed out after $1 seconds" >&2
@@ -109,23 +116,27 @@ fi
 
 # If there are any adapter tests, spin up the HTTP server
 if [ -n "$(filter_matching "adapters" "${test_files[@]}")" ]; then
-  if server_started; then
+  if server_started $port; then
     echo "aborted: another instance of server running on $port" >&2
     exit 1
   fi
   server_pid=$(start_server)
-  wait_for_server 15 || {
+  proxy_pid=$(start_proxy)
+  wait_for_server 15 $port || {
     cat log/test.log
     exit 1
   }
+  wait_for_server 5 $proxy_port
   cleanup() {
     if [ $? -ne 0 ] && [ -n "$TRAVIS" ]; then
       cat log/test.log
     fi
     kill "$server_pid"
+    kill "$proxy_pid"
   }
   trap cleanup INT EXIT
   export LIVE="${scheme}://localhost:${port}"
+  export LIVE_PROXY="http://faraday%40test.local:there%20is%20cake@localhost:${proxy_port}"
 fi
 
 warnings="${TMPDIR:-/tmp}/faraday-warnings.$$"

test/adapters/excon_test.rb

@@ -8,6 +8,10 @@ module Adapters
     Integration.apply(self, :NonParallel) do
       # https://github.com/geemus/excon/issues/126 ?
       undef :test_timeout if ssl_mode?
+
+      # Excon lets OpenSSL::SSL::SSLError be raised without any way to
+      # distinguish whether it happened because of a 407 proxy response
+      undef :test_proxy_auth_fail if ssl_mode?
     end
   end
 end

test/adapters/integration.rb

@@ -172,6 +172,34 @@ module Adapters
         end
       end
 
+      def test_proxy
+        proxy_uri = URI(ENV['LIVE_PROXY'])
+        conn = create_connection(:proxy => proxy_uri)
+
+        res = conn.get '/echo'
+        assert_equal 'get', res.body
+
+        unless self.class.ssl_mode?
+          # proxy can't append "Via" header for HTTPS responses
+          assert_match(/:#{proxy_uri.port}$/, res['via'])
+        end
+      end
+
+      def test_proxy_auth_fail
+        proxy_uri = URI(ENV['LIVE_PROXY'])
+        proxy_uri.password = 'WRONG'
+        conn = create_connection(:proxy => proxy_uri)
+
+        err = assert_raises Faraday::Error::ConnectionFailed do
+          conn.get '/echo'
+        end
+
+        unless self.class.ssl_mode? && self.class.jruby?
+          # JRuby raises "End of file reached" which cannot be distinguished from a 407
+          assert_equal %{407 "Proxy Authentication Required "}, err.message
+        end
+      end
+
       def test_empty_body_response_represented_as_blank_string
         response = get('204')
         assert_equal '', response.body

test/adapters/rack_test.rb

@@ -25,5 +25,7 @@ module Adapters
 
     # test not applicable
     undef test_connection_error
+    undef test_proxy
+    undef test_proxy_auth_fail
   end
 end

test/adapters/typhoeus_test.rb

@@ -13,6 +13,9 @@ module Adapters
       # which libcurl seems to generate for this particular request:
       undef :test_POST_sends_files
 
+      # inconsistent outcomes ranging from successful response to connection error
+      undef :test_proxy_auth_fail if ssl_mode?
+
       def test_binds_local_socket
         host = '1.2.3.4'
         conn = create_connection :request => { :bind => { :host => host } }