Add createFromConfig factory methods

This little bit of syntactical sugar makes it cleaner to use the Config
class to load the system resolver configuration. Which right now is
limited to only one nameserver. By introducing this factory method
completing the implementation in #131 will also allow for instant
multiple server support out of the box without any need for users to
change code on their end to implement it.

Author: WyriHaximus

README.md

@@ -35,11 +35,8 @@ names, baby!
 ```php
 $loop = React\EventLoop\Factory::create();
 
-$config = React\Dns\Config\Config::loadSystemConfigBlocking();
-$server = $config->nameservers ? reset($config->nameservers) : '8.8.8.8';
-
 $factory = new React\Dns\Resolver\Factory();
-$dns = $factory->create($server, $loop);
+$dns = $factory->createFromConfig(React\Dns\Config\Config::loadSystemConfigBlocking(), $loop, '8.8.8.8');
 
 $dns->resolve('igor.io')->then(function ($ip) {
     echo "Host: $ip\n";
@@ -72,11 +69,8 @@ You can cache results by configuring the resolver to use a `CachedExecutor`:
 ```php
 $loop = React\EventLoop\Factory::create();
 
-$config = React\Dns\Config\Config::loadSystemConfigBlocking();
-$server = $config->nameservers ? reset($config->nameservers) : '8.8.8.8';
-
 $factory = new React\Dns\Resolver\Factory();
-$dns = $factory->createCached($server, $loop);
+$dns = $factory->createCachedFromConfig(React\Dns\Config\Config::loadSystemConfigBlocking(), $loop, '8.8.8.8');
 
 $dns->resolve('igor.io')->then(function ($ip) {
     echo "Host: $ip\n";

examples/01-one.php

@@ -7,11 +7,8 @@
 
 $loop = React\EventLoop\Factory::create();
 
-$config = Config::loadSystemConfigBlocking();
-$server = $config->nameservers ? reset($config->nameservers) : '8.8.8.8';
-
 $factory = new Factory();
-$resolver = $factory->create($server, $loop);
+$resolver = $factory->createFromConfig(Config::loadSystemConfigBlocking(), $loop, '8.8.8.8');
 
 $name = isset($argv[1]) ? $argv[1] : 'www.google.com';
 

examples/02-concurrent.php

@@ -7,11 +7,8 @@
 
 $loop = React\EventLoop\Factory::create();
 
-$config = Config::loadSystemConfigBlocking();
-$server = $config->nameservers ? reset($config->nameservers) : '8.8.8.8';
-
 $factory = new Factory();
-$resolver = $factory->create($server, $loop);
+$resolver = $factory->createFromConfig(Config::loadSystemConfigBlocking(), $loop, '8.8.8.8');
 
 $names = array_slice($argv, 1);
 if (!$names) {

examples/03-cached.php

@@ -7,11 +7,8 @@
 
 $loop = React\EventLoop\Factory::create();
 
-$config = Config::loadSystemConfigBlocking();
-$server = $config->nameservers ? reset($config->nameservers) : '8.8.8.8';
-
 $factory = new Factory();
-$resolver = $factory->createCached($server, $loop);
+$resolver = $factory->createCachedFromConfig(Config::loadSystemConfigBlocking(), $loop, '8.8.8.8');
 
 $name = isset($argv[1]) ? $argv[1] : 'www.google.com';
 

examples/11-all-ips.php

@@ -8,11 +8,8 @@
 
 $loop = React\EventLoop\Factory::create();
 
-$config = Config::loadSystemConfigBlocking();
-$server = $config->nameservers ? reset($config->nameservers) : '8.8.8.8';
-
 $factory = new Factory();
-$resolver = $factory->create($server, $loop);
+$resolver = $factory->createFromConfig(Config::loadSystemConfigBlocking(), $loop, '8.8.8.8');
 
 $name = isset($argv[1]) ? $argv[1] : 'www.google.com';
 

examples/12-all-types.php

@@ -10,11 +10,8 @@
 
 $loop = React\EventLoop\Factory::create();
 
-$config = Config::loadSystemConfigBlocking();
-$server = $config->nameservers ? reset($config->nameservers) : '8.8.8.8';
-
 $factory = new Factory();
-$resolver = $factory->create($server, $loop);
+$resolver = $factory->createFromConfig(Config::loadSystemConfigBlocking(), $loop, '8.8.8.8');
 
 $name = isset($argv[1]) ? $argv[1] : 'google.com';
 $type = constant('React\Dns\Model\Message::TYPE_' . (isset($argv[2]) ? $argv[2] : 'TXT'));

examples/13-reverse-dns.php

@@ -8,11 +8,8 @@
 
 $loop = React\EventLoop\Factory::create();
 
-$config = Config::loadSystemConfigBlocking();
-$server = $config->nameservers ? reset($config->nameservers) : '8.8.8.8';
-
 $factory = new Factory();
-$resolver = $factory->create($server, $loop);
+$resolver = $factory->createFromConfig(Config::loadSystemConfigBlocking(), $loop, '8.8.8.8');
 
 $ip = isset($argv[1]) ? $argv[1] : '8.8.8.8';
 

src/Resolver/Factory.php

@@ -4,6 +4,7 @@
 
 use React\Cache\ArrayCache;
 use React\Cache\CacheInterface;
+use React\Dns\Config\Config;
 use React\Dns\Config\HostsFile;
 use React\Dns\Query\CachingExecutor;
 use React\Dns\Query\CoopExecutor;
@@ -18,6 +19,29 @@
 
 final class Factory
 {
+    /**
+     * @param Config        $config
+     * @param LoopInterface $loop
+     * @param string        $fallbackNameserver
+     * @return \React\Dns\Resolver\ResolverInterface
+     */
+    public function createFromConfig(Config $config, LoopInterface $loop, $fallbackNameserver)
+    {
+        return self::create($config->nameservers ? reset($config->nameservers) : $fallbackNameserver, $loop);
+    }
+
+    /**
+     * @param Config          $config
+     * @param LoopInterface   $loop
+     * @param string          $fallbackNameserver
+     * @param ?CacheInterface $cache
+     * @return \React\Dns\Resolver\ResolverInterface
+     */
+    public function createCachedFromConfig(Config $config, LoopInterface $loop, $fallbackNameserver, CacheInterface $cache = null)
+    {
+        return self::createCached($config->nameservers ? reset($config->nameservers) : $fallbackNameserver, $loop, $cache);
+    }
+
     /**
      * @param string        $nameserver
      * @param LoopInterface $loop

tests/Resolver/FactoryTest.php

@@ -2,12 +2,24 @@
 
 namespace React\Tests\Dns\Resolver;
 
+use React\Dns\Config\Config;
 use React\Dns\Resolver\Factory;
 use React\Tests\Dns\TestCase;
 use React\Dns\Query\HostsFileExecutor;
 
 class FactoryTest extends TestCase
 {
+    /** @test */
+    public function createFromConfigShouldCreateResolver()
+    {
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
+
+        $factory = new Factory();
+        $resolver = $factory->createFromConfig(Config::loadSystemConfigBlocking(), $loop, '8.8.8.8:53');
+
+        $this->assertInstanceOf('React\Dns\Resolver\Resolver', $resolver);
+    }
+
     /** @test */
     public function createShouldCreateResolver()
     {
@@ -159,6 +171,21 @@ public function createCachedShouldCreateResolverWithCachingExecutor()
         $this->assertInstanceOf('React\Cache\ArrayCache', $cache);
     }
 
+    /** @test */
+    public function createCachedFromConfigShouldCreateResolverWithCachingExecutor()
+    {
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
+
+        $factory = new Factory();
+        $resolver = $factory->createCachedFromConfig(Config::loadSystemConfigBlocking(), $loop, '8.8.8.8:53');
+
+        $this->assertInstanceOf('React\Dns\Resolver\Resolver', $resolver);
+        $executor = $this->getResolverPrivateExecutor($resolver);
+        $this->assertInstanceOf('React\Dns\Query\CachingExecutor', $executor);
+        $cache = $this->getCachingExecutorPrivateMemberValue($executor, 'cache');
+        $this->assertInstanceOf('React\Cache\ArrayCache', $cache);
+    }
+
     /** @test */
     public function createCachedShouldCreateResolverWithCachingExecutorWithCustomCache()
     {