Allow to use when() rule without else

README.md

@@ -1932,11 +1932,12 @@ See also:
   * [v::consonant()](#vconsonant)
 
 #### v::when(v $if, v $then, v $else)
+#### v::when(v $if, v $then)
 
 A ternary validator that accepts three parameters.
 
-When the $if validates, returns validation for $then.
-When the $if doesn't validate, returns validation for $else.
+When the `$if` validates, returns validation for `$then`.
+When the `$if` doesn't validate, returns validation for `$else`, if defined.
 
 ```php
 v::when(v::int(), v::positive(), v::notEmpty())->validate($input);
@@ -1944,6 +1945,7 @@ v::when(v::int(), v::positive(), v::notEmpty())->validate($input);
 
 In the sample above, if `$input` is an integer, then it must be positive.
 If `$input` is not an integer, then it must not me empty.
+When `$else` is not defined use [v::alwaysInvalid()](#valwaysinvalid) as default.
 
 See also:
 

library/Exceptions/AlwaysInvalidException.php

@@ -3,12 +3,16 @@ namespace Respect\Validation\Exceptions;
 
 class AlwaysInvalidException extends ValidationException
 {
+    const SIMPLE = 0;
+
     public static $defaultTemplates = array(
         self::MODE_DEFAULT => array(
             self::STANDARD => '{{name}} is always invalid',
+            self::SIMPLE   => '{{name}} is not valid',
         ),
         self::MODE_NEGATIVE => array(
             self::STANDARD => '{{name}} is always valid',
+            self::SIMPLE   => '{{name}} is valid',
         ),
     );
 }

library/Rules/When.php

@@ -2,6 +2,7 @@
 namespace Respect\Validation\Rules;
 
 use Respect\Validation\Validatable;
+use Respect\Validation\Exceptions\AlwaysInvalidException;
 
 class When extends AbstractRule
 {
@@ -9,10 +10,15 @@ class When extends AbstractRule
     public $then;
     public $else;
 
-    public function __construct(Validatable $when, Validatable $then, Validatable $else)
+    public function __construct(Validatable $when, Validatable $then, Validatable $else = null)
     {
         $this->when = $when;
         $this->then = $then;
+        if (null === $else) {
+            $else = new AlwaysInvalid();
+            $else->setTemplate(AlwaysInvalidException::SIMPLE);
+        }
+
         $this->else = $else;
     }
 

library/Validator.php

@@ -93,7 +93,7 @@ use Respect\Validation\Rules\AllOf;
  * @method static Validator uppercase()
  * @method static Validator version()
  * @method static Validator vowel()
- * @method static Validator when(Validatable $if, Validatable $then, Validatable $when)
+ * @method static Validator when(Validatable $if, Validatable $then, Validatable $when = null)
  * @method static Validator writable()
  * @method static Validator xdigit(string $additionalChars = null)
  * @method static Validator yes($useLocale = false)

tests/Rules/WhenTest.php

@@ -1,6 +1,9 @@
 <?php
 namespace Respect\Validation\Rules;
 
+/**
+ * @covers Respect\Validation\Rules\When
+ */
 class WhenTest extends \PHPUnit_Framework_TestCase
 {
     public function testWhenHappypath()
@@ -9,11 +12,37 @@ class WhenTest extends \PHPUnit_Framework_TestCase
         $this->assertTrue($v->validate(3));
         $this->assertTrue($v->validate('aaa'));
     }
+
     public function testWhenError()
     {
         $v = new When(new Int(), new Between(1,5), new NotEmpty());
         $this->assertFalse($v->validate(15));
     }
+
+    public function testWhenWithoutElseHappypath()
+    {
+        $v = new When(new Int(), new Between(1,5));
+
+        $this->assertTrue($v->validate(3));
+    }
+
+    public function testWhenWithoutElseError()
+    {
+        $v = new When(new String(), new Between(1,5));
+
+        $this->assertFalse($v->validate(15));
+    }
+
+    /**
+     * @expectedException Respect\Validation\Exceptions\AlwaysInvalidException
+     * @expectedExceptionMessage "15" is not valid
+     */
+    public function testWhenWithoutElseAssert()
+    {
+        $v = new When(new String(), new Between(1,5));
+        $v->assert(15);
+    }
+
     /**
      * @expectedException Respect\Validation\Exceptions\BetweenException
      */
@@ -22,6 +51,7 @@ class WhenTest extends \PHPUnit_Framework_TestCase
         $v = new When(new Int(), new Between(1,5), new NotEmpty());
         $this->assertFalse($v->assert(15));
     }
+
     /**
      * @expectedException Respect\Validation\Exceptions\NotEmptyException
      */
@@ -30,6 +60,7 @@ class WhenTest extends \PHPUnit_Framework_TestCase
         $v = new When(new Int(), new Between(1,5), new NotEmpty());
         $this->assertFalse($v->assert(''));
     }
+
     /**
      * @expectedException Respect\Validation\Exceptions\MaxException
      */
@@ -38,6 +69,7 @@ class WhenTest extends \PHPUnit_Framework_TestCase
         $v = new When(new Int(), new Between(1,5), new NotEmpty());
         $this->assertFalse($v->check(15));
     }
+
     /**
      * @expectedException Respect\Validation\Exceptions\NotEmptyException
      */