[9.x] Add RequiredIfAccepted validation rule (#44035)

* RequiredIfAccepted validation rule

* RequiredIfAccepted attribute placeholder replacer + styling fixes

* Update ValidatesAttributes.php

Author: pascalbaljet

src/Illuminate/Validation/Concerns/ReplacesAttributes.php

@@ -434,6 +434,22 @@ protected function replaceRequiredIf($message, $attribute, $rule, $parameters)
         return str_replace([':other', ':value'], $parameters, $message);
     }
 
+    /**
+     * Replace all place-holders for the required_if_accepted rule.
+     *
+     * @param  string  $message
+     * @param  string  $attribute
+     * @param  string  $rule
+     * @param  array<int,string>  $parameters
+     * @return string
+     */
+    protected function replaceRequiredIfAccepted($message, $attribute, $rule, $parameters)
+    {
+        $parameters[0] = $this->getDisplayableAttribute($parameters[0]);
+
+        return str_replace([':other'], $parameters, $message);
+    }
+
     /**
      * Replace all place-holders for the required_unless rule.
      *

src/Illuminate/Validation/Concerns/ValidatesAttributes.php

@@ -1601,6 +1601,25 @@ public function validateRequiredIf($attribute, $value, $parameters)
         return true;
     }
 
+    /**
+     * Validate that an attribute exists when another attribute was "accepted".
+     *
+     * @param  string  $attribute
+     * @param  mixed  $value
+     * @param  mixed  $parameters
+     * @return bool
+     */
+    public function validateRequiredIfAccepted($attribute, $value, $parameters)
+    {
+        $this->requireParameterCount(1, $parameters, 'required_if_accepted');
+
+        if ($this->validateAccepted($parameters[0], $this->getValue($parameters[0]))) {
+            return $this->validateRequired($attribute, $value);
+        }
+
+        return true;
+    }
+
     /**
      * Validate that an attribute does not exist.
      *

src/Illuminate/Validation/Validator.php

@@ -210,6 +210,7 @@ class Validator implements ValidatorContract
         'Present',
         'Required',
         'RequiredIf',
+        'RequiredIfAccepted',
         'RequiredUnless',
         'RequiredWith',
         'RequiredWithAll',
@@ -240,6 +241,7 @@ class Validator implements ValidatorContract
         'AcceptedIf',
         'DeclinedIf',
         'RequiredIf',
+        'RequiredIfAccepted',
         'RequiredUnless',
         'RequiredWith',
         'RequiredWithAll',

tests/Validation/ValidationValidatorTest.php

@@ -1972,6 +1972,22 @@ public function testValidateAccepted()
         $this->assertTrue($v->passes());
     }
 
+    public function testValidateRequiredAcceptedIf()
+    {
+        $trans = $this->getIlluminateArrayTranslator();
+        $v = new Validator($trans, ['foo' => 'no', 'bar' => 'baz'], ['bar' => 'required_if_accepted:foo']);
+        $this->assertTrue($v->passes());
+
+        $v = new Validator($trans, ['foo' => 'yes', 'bar' => 'baz'], ['bar' => 'required_if_accepted:foo']);
+        $this->assertTrue($v->passes());
+
+        $v = new Validator($trans, ['foo' => 'no', 'bar' => ''], ['bar' => 'required_if_accepted:foo']);
+        $this->assertTrue($v->passes());
+
+        $v = new Validator($trans, ['foo' => 'yes', 'bar' => ''], ['bar' => 'required_if_accepted:foo']);
+        $this->assertFalse($v->passes());
+    }
+
     public function testValidateAcceptedIf()
     {
         $trans = $this->getIlluminateArrayTranslator();