📝 Add some docblocks

src/Converter.php

@@ -13,13 +13,23 @@
  */
 class Converter
 {
+    /**
+     * @var Converter
+     */
     private static $instance;
 
+    /**
+     * Create a new Converter object that you can later get through "::get()"
+     * @param  SourceInterface $source
+     */
     public static function initialize(SourceInterface $source)
     {
         self::$instance = new static($source);
     }
 
+    /**
+     * @return Converter
+     */
     public static function get()
     {
         if (! self::$instance) {
@@ -29,23 +39,38 @@ public static function get()
         return self::$instance;
     }
 
+    /**
+     * Clear the object, returned through "::get"
+     */
     public static function clear()
     {
         self::$instance = null;
     }
 
+    /**
+     * @var SourceInterface
+     */
     private $source;
 
     public function __construct(SourceInterface $source)
     {
         $this->source = $source;
     }
 
+    /**
+     * @return SourceInterface
+     */
     public function getSource()
     {
         return $this->source;
     }
 
+    /**
+     * @param  Money    $money
+     * @param  Currency $to
+     * @param  int      $roundingMode
+     * @return Money
+     */
     public function convert(Money $money, Currency $to, $roundingMode = PHP_ROUND_HALF_UP)
     {
         $new = new Money($money->getAmount(), $to);

src/ECBSource.php

@@ -15,9 +15,20 @@
  */
 class ECBSource implements SourceInterface
 {
-    private $rates = array();
+    /**
+     * @var array
+     */
+    private $rates;
+
+    /**
+     * @var CachedRemoteData
+     */
     private $cachedRemoteData;
 
+    /**
+     * @param CacheItemPoolInterface $cachePool
+     * @param string                 $key
+     */
     public function __construct(CacheItemPoolInterface $cachePool, $key = 'ECBSource')
     {
         $this->cachedRemoteData = new CachedRemoteData(
@@ -27,16 +38,27 @@ public function __construct(CacheItemPoolInterface $cachePool, $key = 'ECBSource
         );
     }
 
+    /**
+     * @return CachedRemoteData
+     */
     public function getCachedRemoteData()
     {
         return $this->cachedRemoteData;
     }
 
+    /**
+     * @return string
+     * @throws Exception If error retrieving remote data
+     */
     public function getData()
     {
         return $this->cachedRemoteData->get();
     }
 
+    /**
+     * @return array
+     * @throws Exception If error retrieving remote data
+     */
     public function getRates()
     {
         if (! $this->rates) {
@@ -58,6 +80,11 @@ public function getRates()
         return $this->rates;
     }
 
+    /**
+     * @param  Currency $currency
+     * @return float
+     * @throws Exception If error retrieving remote data
+     */
     public function getRate(Currency $currency)
     {
         $rates = $this->getRates();
@@ -72,6 +99,11 @@ public function getRate(Currency $currency)
         return (float) $rates[$code];
     }
 
+    /**
+     * @param  Currency $from
+     * @param  Currency $to
+     * @return float
+     */
     public function getRateBetween(Currency $from, Currency $to)
     {
         $from = $this->getRate($from);

src/NullSource.php

@@ -11,8 +11,13 @@
  */
 class NullSource implements SourceInterface
 {
+    /**
+     * @param  Currency $from
+     * @param  Currency $to
+     * @return float
+     */
     public function getRateBetween(Currency $from, Currency $to)
     {
-        return 1;
+        return 1.0;
     }
 }

src/SourceInterface.php

@@ -11,5 +11,10 @@
  */
 interface SourceInterface
 {
+    /**
+     * @param  Currency $from
+     * @param  Currency $to
+     * @return float
+     */
     public function getRateBetween(Currency $from, Currency $to);
 }