[Config] Add ExprBuilder::ifEmpty()

Author: ogizanagi

Definition/Builder/ExprBuilder.php

@@ -97,6 +97,18 @@ public function ifNull()
         return $this;
     }
 
+    /**
+     * Tests if the value is empty.
+     *
+     * @return ExprBuilder
+     */
+    public function ifEmpty()
+    {
+        $this->ifPart = function ($v) { return empty($v); };
+
+        return $this;
+    }
+
     /**
      * Tests if the value is an array.
      *

Tests/Definition/Builder/ExprBuilderTest.php

@@ -75,6 +75,21 @@ public function testIfNullExpression()
         $this->assertFinalizedValueIs('value', $test);
     }
 
+    public function testIfEmptyExpression()
+    {
+        $test = $this->getTestBuilder()
+            ->ifEmpty()
+            ->then($this->returnClosure('new_value'))
+        ->end();
+        $this->assertFinalizedValueIs('new_value', $test, array('key' => array()));
+
+        $test = $this->getTestBuilder()
+            ->ifEmpty()
+            ->then($this->returnClosure('new_value'))
+        ->end();
+        $this->assertFinalizedValueIs('value', $test);
+    }
+
     public function testIfArrayExpression()
     {
         $test = $this->getTestBuilder()