Adding support for nullable values.

readme.md

@@ -58,6 +58,7 @@
 - [MinMaxLength](https://github.com/weew/validator/blob/master/src/Weew/Validator/Constraints/MinMaxLengthConstraint.php)
 - [NotEmpty](https://github.com/weew/validator/blob/master/src/Weew/Validator/Constraints/NotEmptyConstraint.php)
 - [NotNull](https://github.com/weew/validator/blob/master/src/Weew/Validator/Constraints/NotNullConstraint.php)
+- [Nullable](https://github.com/weew/validator/blob/master/src/Weew/Validator/Constraints/NullableConstraint.php)
 - [Null](https://github.com/weew/validator/blob/master/src/Weew/Validator/Constraints/NullConstraint.php)
 - [Numeric](https://github.com/weew/validator/blob/master/src/Weew/Validator/Constraints/NumericConstraint.php)
 - [Regex](https://github.com/weew/validator/blob/master/src/Weew/Validator/Constraints/RegexConstraint.php)

src/Weew/Validator/Constraints/NullableConstraint.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace Weew\Validator\Constraints;
+
+use Weew\Validator\IConstraint;
+use Weew\Validator\IValidationData;
+
+/**
+ * This constraint is used to allow to tag a specific
+ * subject as "optional". Validator will remove any errors
+ * that occurred for the given subject if the subject value
+ * is null or '' where this constraint has been applied.
+ */
+class NullableConstraint implements IConstraint {
+    /**
+     * @var string
+     */
+    protected $message;
+
+    /**
+     * FloatConstraint constructor.
+     *
+     * @param string $message
+     */
+    public function __construct($message = null) {
+        $this->message = $message;
+    }
+
+    /**
+     * @param $value
+     * @param IValidationData $data
+     *
+     * @return bool
+     */
+    public function check($value, IValidationData $data = null) {
+        return array_contains([null, ''], $value) ? false : true;
+    }
+
+    /**
+     * @return string
+     */
+    public function getMessage() {
+        if ($this->message !== null) {
+            return $this->message;
+        }
+
+        return 'May be null.';
+    }
+
+    /**
+     * @return array
+     */
+    public function getOptions() {
+        return [];
+    }
+}

src/Weew/Validator/ValidationResultFilter.php

@@ -0,0 +1,62 @@
+<?php
+
+namespace Weew\Validator;
+
+use Weew\Validator\Constraints\NullableConstraint;
+
+class ValidationResultFilter {
+    /**
+     * @param IValidationResult $result
+     *
+     * @return IValidationResult
+     */
+    public function removeNullableErrors(IValidationResult $result) {
+        $nullableSubjects = $this->getNullableSubjects($result);
+        $filteredResult = new ValidationResult();
+
+        foreach ($result->getErrors() as $error) {
+            if ( ! $this->shouldErrorBeIgnored($nullableSubjects, $error)) {
+                $filteredResult->addError($error);
+            }
+        }
+
+        return $filteredResult;
+    }
+
+    /**
+     * @param IValidationResult $result
+     *
+     * @return array
+     */
+    protected function getNullableSubjects(IValidationResult $result) {
+        $nullableSubjects = [];
+
+        foreach ($result->getErrors() as $error) {
+            if ($error->getConstraint() instanceof NullableConstraint) {
+                $nullableSubjects[] = $error->getSubject();
+            }
+        }
+
+        return $nullableSubjects;
+    }
+
+    /**
+     * @param array $nullableSubjects
+     * @param IValidationError $error
+     *
+     * @return bool
+     */
+    protected function shouldErrorBeIgnored(array $nullableSubjects, IValidationError $error) {
+        if ($error->getConstraint() instanceof NullableConstraint) {
+            return true;
+        }
+
+        foreach ($nullableSubjects as $subject) {
+            if (str_starts_with($error->getSubject(), $subject)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+}

src/Weew/Validator/Validator.php

@@ -147,7 +147,18 @@ protected function applyConstraints($data, array $groups) {
             }
         }
 
-        return $result;
+        return $this->filterResult($result);
+    }
+
+    /**
+     * @param IValidationResult $result
+     *
+     * @return ValidationResult
+     */
+    protected function filterResult(IValidationResult $result) {
+        $resultFilter = new ValidationResultFilter();
+
+        return $resultFilter->removeNullableErrors($result);
     }
 
     /**

tests/Weew/Validator/Constraints/NullableConstraintTest.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace Tests\Weew\Validator\Constraints;
+
+use PHPUnit_Framework_TestCase;
+use Weew\Validator\Constraints\NullableConstraint;
+
+class NullableConstraintTest extends PHPUnit_Framework_TestCase {
+    public function test_check() {
+        $c = new NullableConstraint();
+        $this->assertFalse($c->check(''));
+        $this->assertFalse($c->check(null));
+        $this->assertTrue($c->check('foo'));
+        $this->assertTrue($c->check(22));
+    }
+
+    public function test_get_options() {
+        $c = new NullableConstraint();
+        $this->assertEquals([], $c->getOptions());
+    }
+
+    public function test_get_message() {
+        $c = new NullableConstraint('foo');
+        $this->assertEquals('foo', $c->getMessage());
+
+        $c = new NullableConstraint();
+        $this->assertNotNull($c->getMessage());
+    }
+}

tests/Weew/Validator/ValidationResultFilterTest.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Tests\Weew\Validator;
+
+use PHPUnit_Framework_TestCase;
+use Weew\Validator\Constraints\NotNullConstraint;
+use Weew\Validator\Constraints\NullableConstraint;
+use Weew\Validator\ValidationError;
+use Weew\Validator\ValidationResult;
+use Weew\Validator\ValidationResultFilter;
+
+class ValidationResultFilterTest extends PHPUnit_Framework_TestCase {
+    public function test_removes_nullable_errors() {
+        $error1 = new ValidationError('foo.bar.baz', 'baz', new NotNullConstraint());
+        $error2 = new ValidationError('foo.bar.yolo', 'baz', new NotNullConstraint());
+        $error3 = new ValidationError('some.value', 'baz', new NotNullConstraint());
+        $error4 = new ValidationError('another.value', 'baz', new NotNullConstraint());
+        $error5 = new ValidationError('foo.bar', 'baz', new NullableConstraint());
+        $error6 = new ValidationError('foo', 'baz', new NotNullConstraint());
+        $errors = [$error1, $error2, $error3, $error4, $error5, $error6];
+
+        $result = new ValidationResult($errors);
+        $filter = new ValidationResultFilter();
+        $filteredResult = $filter->removeNullableErrors($result);
+
+        $this->assertEquals(3, $filteredResult->getErrorCount());
+        $this->assertTrue($filteredResult->getErrors()[0] === $error3);
+        $this->assertTrue($filteredResult->getErrors()[1] === $error4);
+        $this->assertTrue($filteredResult->getErrors()[2] === $error6);
+    }
+}