[6.x] Fix nullable values for required_if (#37128)

* Fix nullable values for required_if

* Reword null value

Author: driesvints

src/Illuminate/Validation/Concerns/FormatsMessages.php

@@ -336,6 +336,10 @@ public function getDisplayableValue($attribute, $value)
             return $value ? 'true' : 'false';
         }
 
+        if (is_null($value)) {
+            return 'empty';
+        }
+
         return $value;
     }
 

src/Illuminate/Validation/Concerns/ValidatesAttributes.php

@@ -1420,9 +1420,13 @@ public function validateRequiredIf($attribute, $value, $parameters)
     {
         $this->requireParameterCount(2, $parameters, 'required_if');
 
+        if (! Arr::has($this->data, $parameters[0])) {
+            return true;
+        }
+
         [$values, $other] = $this->prepareValuesAndOther($parameters);
 
-        if (in_array($other, $values, is_bool($other))) {
+        if (in_array($other, $values, is_bool($other) || is_null($other))) {
             return $this->validateRequired($attribute, $value);
         }
 
@@ -1441,9 +1445,13 @@ public function validateExcludeIf($attribute, $value, $parameters)
     {
         $this->requireParameterCount(2, $parameters, 'exclude_if');
 
+        if (! Arr::has($this->data, $parameters[0])) {
+            return true;
+        }
+
         [$values, $other] = $this->prepareValuesAndOther($parameters);
 
-        return ! in_array($other, $values, is_bool($other));
+        return ! in_array($other, $values, is_bool($other) || is_null($other));
     }
 
     /**
@@ -1458,9 +1466,38 @@ public function validateExcludeUnless($attribute, $value, $parameters)
     {
         $this->requireParameterCount(2, $parameters, 'exclude_unless');
 
+        if (! Arr::has($this->data, $parameters[0])) {
+            return true;
+        }
+
         [$values, $other] = $this->prepareValuesAndOther($parameters);
 
-        return in_array($other, $values, is_bool($other));
+        return in_array($other, $values, is_bool($other) || is_null($other));
+    }
+
+    /**
+     * Validate that an attribute exists when another attribute does not have a given value.
+     *
+     * @param  string  $attribute
+     * @param  mixed  $value
+     * @param  mixed  $parameters
+     * @return bool
+     */
+    public function validateRequiredUnless($attribute, $value, $parameters)
+    {
+        $this->requireParameterCount(2, $parameters, 'required_unless');
+
+        if (! Arr::has($this->data, $parameters[0])) {
+            return true;
+        }
+
+        [$values, $other] = $this->prepareValuesAndOther($parameters);
+
+        if (! in_array($other, $values, is_bool($other) || is_null($other))) {
+            return $this->validateRequired($attribute, $value);
+        }
+
+        return true;
     }
 
     /**
@@ -1479,6 +1516,10 @@ protected function prepareValuesAndOther($parameters)
             $values = $this->convertValuesToBoolean($values);
         }
 
+        if ($this->shouldConvertToNull($parameters[0]) || is_null($other)) {
+            $values = $this->convertValuesToNull($values);
+        }
+
         return [$values, $other];
     }
 
@@ -1493,6 +1534,17 @@ protected function shouldConvertToBoolean($parameter)
         return in_array('boolean', Arr::get($this->rules, $parameter, []));
     }
 
+    /**
+     * Check if parameter should be converted to null.
+     *
+     * @param  string  $parameter
+     * @return bool
+     */
+    protected function shouldConvertToNull($parameter)
+    {
+        return in_array('nullable', Arr::get($this->rules, $parameter, []));
+    }
+
     /**
      * Convert the given values to boolean if they are string "true" / "false".
      *
@@ -1513,24 +1565,20 @@ protected function convertValuesToBoolean($values)
     }
 
     /**
-     * Validate that an attribute exists when another attribute does not have a given value.
+     * Convert the given values to null if they are string "null".
      *
-     * @param  string  $attribute
-     * @param  mixed  $value
-     * @param  mixed  $parameters
-     * @return bool
+     * @param  array  $values
+     * @return array
      */
-    public function validateRequiredUnless($attribute, $value, $parameters)
+    protected function convertValuesToNull($values)
     {
-        $this->requireParameterCount(2, $parameters, 'required_unless');
-
-        [$values, $other] = $this->prepareValuesAndOther($parameters);
-
-        if (! in_array($other, $values, is_bool($other))) {
-            return $this->validateRequired($attribute, $value);
-        }
+        return array_map(function ($value) {
+            if ($value === 'null') {
+                return null;
+            }
 
-        return true;
+            return $value;
+        }, $values);
     }
 
     /**

tests/Validation/ValidationValidatorTest.php

@@ -1094,13 +1094,44 @@ public function testRequiredIf()
         $trans = $this->getIlluminateArrayTranslator();
         $trans->addLines(['validation.required_if' => 'The :attribute field is required when :other is :value.'], 'en');
         $v = new Validator($trans, ['foo' => 0], [
-            'foo' => 'required|boolean',
+            'foo' => 'nullable|required|boolean',
             'bar' => 'required_if:foo,true',
             'baz' => 'required_if:foo,false',
         ]);
         $this->assertTrue($v->fails());
         $this->assertCount(1, $v->messages());
         $this->assertSame('The baz field is required when foo is 0.', $v->messages()->first('baz'));
+
+        $trans = $this->getIlluminateArrayTranslator();
+        $v = new Validator($trans, [], [
+            'foo' => 'nullable|boolean',
+            'baz' => 'nullable|required_if:foo,false',
+        ]);
+        $this->assertTrue($v->passes());
+
+        $trans = $this->getIlluminateArrayTranslator();
+        $v = new Validator($trans, ['foo' => null], [
+            'foo' => 'nullable|boolean',
+            'baz' => 'nullable|required_if:foo,false',
+        ]);
+        $this->assertTrue($v->passes());
+
+        $trans = $this->getIlluminateArrayTranslator();
+        $v = new Validator($trans, [], [
+            'foo' => 'nullable|boolean',
+            'baz' => 'nullable|required_if:foo,null',
+        ]);
+        $this->assertTrue($v->passes());
+
+        $trans = $this->getIlluminateArrayTranslator();
+        $trans->addLines(['validation.required_if' => 'The :attribute field is required when :other is :value.'], 'en');
+        $v = new Validator($trans, ['foo' => null], [
+            'foo' => 'nullable|boolean',
+            'baz' => 'nullable|required_if:foo,null',
+        ]);
+        $this->assertTrue($v->fails());
+        $this->assertCount(1, $v->messages());
+        $this->assertSame('The baz field is required when foo is empty.', $v->messages()->first('baz'));
     }
 
     public function testRequiredUnless()