moar tests for native resolver paths

.rubocop_todo.yml

@@ -11,7 +11,7 @@ Metrics/ModuleLength:
   Max: 325
 
 Metrics/BlockLength:
-  Max: 200
+  Max: 500
 
 Metrics/BlockNesting:
   Enabled: False

test/support/requests/resolvers.rb

@@ -77,6 +77,51 @@ module Requests
           verify_error_response(response, HTTPX::ResolveError)
         end
       when :native
+        define_method :"test_resolver_#{resolver_type}_tcp_request" do
+          tcp_socket = nil
+          resolver_class = Class.new(HTTPX::Resolver::Native) do
+            define_method :build_socket do
+              tcp_socket = super()
+            end
+          end
+
+          session = HTTPX.plugin(SessionWithPool)
+          uri = build_uri("/get")
+          response = session.head(uri, resolver_class: resolver_class, resolver_options: options.merge(socket_type: :tcp))
+          verify_status(response, 200)
+          response.close
+
+          assert !tcp_socket.nil?
+          assert tcp_socket.is_a?(HTTPX::TCP)
+        end
+
+        define_method :"test_resolver_#{resolver_type}_same_relative_name" do
+          addresses = nil
+          resolver_class = Class.new(HTTPX::Resolver::Native) do
+            define_method :parse_addresses do |addrs|
+              addresses = addrs
+              super(addrs)
+            end
+          end
+
+          start_test_servlet(DNSSameRelativeName, 0.2) do |slow_dns_server|
+            start_test_servlet(DNSSameRelativeName, 0.2) do |not_so_slow_dns_server|
+              nameservers = [slow_dns_server.nameserver, not_so_slow_dns_server.nameserver]
+
+              resolver_opts = options.merge(nameserver: nameservers)
+
+              session = HTTPX.plugin(SessionWithPool)
+              uri = URI(build_uri("/get"))
+              response = session.head(uri, resolver_class: resolver_class, resolver_options: resolver_opts)
+              verify_status(response, 200)
+              response.close
+
+              assert !addresses.nil?
+              addr = addresses.first
+              assert addr["name"] != uri.host
+            end
+          end
+        end
 
         # this test mocks an unresponsive DNS server which doesn't return a DNS asnwer back.
         define_method :"test_resolver_#{resolver_type}_timeout" do
@@ -205,6 +250,23 @@ module Requests
 
           assert resolver_class.ios.any?(HTTPX::TCP), "resolver did not upgrade to tcp"
         end
+
+        define_method :"test_resolver_#{resolver_type}_no_addresses" do
+          start_test_servlet(DNSNoAddress, 0.2) do |slow_dns_server|
+            start_test_servlet(DNSNoAddress, 0.2) do |not_so_slow_dns_server|
+              nameservers = [slow_dns_server.nameserver, not_so_slow_dns_server.nameserver]
+
+              resolver_opts = options.merge(nameserver: nameservers)
+
+              HTTPX.plugin(SessionWithPool).wrap do |session|
+                uri = build_uri("/get")
+
+                response = session.get(uri, resolver_class: resolver_type, resolver_options: resolver_opts)
+                verify_error_response(response, /Can't resolve/)
+              end
+            end
+          end
+        end
       end
     end
   end

test/support/servlets/dns_no_address.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require "resolv"
+require_relative "test"
+
+# from https://gist.github.com/peterc/1425383
+
+class DNSNoAddress < TestDNSResolver
+  private
+
+  def dns_response(query)
+    domain = extract_domain(query)
+    ip = Resolv.getaddress(domain)
+    cname = ip =~ /[a-z]/
+
+    # Valid response header
+    response = "#{query[0, 2]}\x81\x00#{query[4, 2]}\x00\x00\x00\x00\x00\x00".b
+
+    # Append original question section
+    response << query[12..-1].b
+
+    # Use pointer to refer to domain name in question section
+    response << "\xc0\x0c".b
+    response
+  end
+end

test/support/servlets/dns_same_relative_name.rb

@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+require "resolv"
+require_relative "test"
+
+# from https://gist.github.com/peterc/1425383
+
+class DNSSameRelativeName < TestDNSResolver
+  private
+
+  def dns_response(query)
+    domain = extract_domain(query)
+    ip = Resolv.getaddress(domain)
+    cname = ip =~ /[a-z]/
+
+    # Valid response header
+    response = "#{query[0, 2]}\x81\x00#{query[4, 2] * 2}\x00\x00\x00\x00".b
+
+    # Append original question section
+    response << [domain.size].pack("C") << domain.b << query[-5..-1]
+
+    # Use pointer to refer to domain name in question section
+    response << "\xc0\x0c".b
+
+    # Set response type accordingly
+    response << (cname ? "\x00\x05".b : "\x00\x01".b)
+
+    # Set response class (IN)
+    response << "\x00\x01".b
+
+    # TTL in seconds
+    response << [120].pack("N").b
+
+    # Calculate RDATA - we need its length in advance
+    rdata = if cname
+      ip.split(".").map { |a| a.length.chr + a }.join << "\x00"
+    else
+      # Append IP address as four 8 bit unsigned bytes
+      ip.split(".").map(&:to_i).pack("C*")
+    end
+
+    # RDATA is 4 bytes
+    response << [rdata.length].pack("n").b
+    response << rdata.b
+    response
+  end
+end