Added unit tests.

Author: tfbrito

src/Fields/FileField.php

@@ -31,9 +31,9 @@ public function __construct(array $args = array())
 
     public function validate($value)
     {
-        if ((!isset($value->size) && $this->isDisabled()) || 0 == $value->size && !$this->required) {
+        if ((!isset($value->size) || 0 == $value->size) && !$this->required) {
             return;
-        } elseif (!isset($value->size) && !$this->isDisabled()) {
+        } elseif (!isset($value->size) && $this->required) {
             throw new ValidationError(msg("INVALID_FILE"), 'invalid');
         }
 

tests/unit/Fields/FileFieldTest.php

@@ -55,6 +55,22 @@ public function testValidateMaxSize()
         $this->field->validate((object) $data);
     }
 
+    public function testValidateNull()
+    {
+        $result = $this->field->validate(null);
+        $this->assertNull($result);
+    }
+
+    /**
+     * @expectedException PHPForm\Exceptions\ValidationError
+     * @expectedExceptionMessage Invalid file submitted.
+     */
+    public function testValidateInvalid()
+    {
+        $field = new FileField(["max_size" => 20, 'required' => true]);
+        $field->validate(null);
+    }
+
     public function testToNative()
     {
         $data = array(