Properties: Implement iteration support

src/Properties.php

@@ -3,6 +3,7 @@
 namespace ipl\Stdlib;
 
 use OutOfBoundsException;
+use Traversable;
 
 /**
  * Trait for property access, mutation and array access.
@@ -83,6 +84,18 @@ protected function setProperty($key, $value)
         return $this;
     }
 
+    /**
+     * Iterate over all existing properties
+     *
+     * @return Traversable
+     */
+    public function getIterator(): Traversable
+    {
+        foreach ($this->properties as $key => $value) {
+            yield $key => $value;
+        }
+    }
+
     /**
      * Check whether an offset exists
      *

tests/PropertiesTest.php

@@ -96,6 +96,28 @@ public function testUnsetForPropertyAccess()
         $subject->foo;
     }
 
+    public function testPropertyIterationWorks()
+    {
+        $subject = new TestClassUsingThePropertiesTrait();
+        $subject->foo = 'bar';
+        $subject->bar = 'foo';
+
+        $i = 0;
+        foreach ($subject as $name => $value) {
+            if ($i === 0) {
+                $this->assertEquals($name, 'foo');
+                $this->assertEquals($value, 'bar');
+            } elseif ($i === 1) {
+                $this->assertEquals($name, 'bar');
+                $this->assertEquals($value, 'foo');
+            } else {
+                $this->fail('There are more properties iterable than defined');
+            }
+
+            $i++;
+        }
+    }
+
     public function testGetPropertiesReturnsEmptyArrayIfUnset()
     {
         $this->markTestSkipped('Properties::getProperties() not yet implemented');

tests/TestClassUsingThePropertiesTrait.php

@@ -4,7 +4,7 @@
 
 use ipl\Stdlib\Properties;
 
-class TestClassUsingThePropertiesTrait implements \ArrayAccess
+class TestClassUsingThePropertiesTrait implements \ArrayAccess, \IteratorAggregate
 {
     use Properties;
 }