Apply contribution guidelines to "Negative" rule

Also does not allow validation of non-numeric values.

Co-Authored-By: Henrique Moody <henriquemoody@gmail.com>

docs/Negative.md

@@ -2,7 +2,7 @@
 
 - `Negative()`
 
-Validates if a number is lower than zero
+Validates whether the input is a negative number.
 
 ```php
 v::numericVal()->negative()->validate(-15); // true
@@ -12,6 +12,7 @@ v::numericVal()->negative()->validate(-15); // true
 
 Version | Description
 --------|-------------
+  2.0.0 | Does not validate non-numeric values
   0.3.9 | Created
 
 ***

library/Exceptions/NegativeException.php

@@ -13,8 +13,16 @@ declare(strict_types=1);
 
 namespace Respect\Validation\Exceptions;
 
-class NegativeException extends ValidationException
+/**
+ * @author Alexandre Gomes Gaigalas <alexandre@gaigalas.net>
+ * @author Henrique Moody <henriquemoody@gmail.com>
+ * @author Ismael Elias <ismael.esq@hotmail.com>
+ */
+final class NegativeException extends ValidationException
 {
+    /**
+     * {@inheritdoc}
+     */
     public static $defaultTemplates = [
         self::MODE_DEFAULT => [
             self::STANDARD => '{{name}} must be negative',

library/Rules/Negative.php

@@ -13,10 +13,26 @@ declare(strict_types=1);
 
 namespace Respect\Validation\Rules;
 
-class Negative extends AbstractRule
+use function is_numeric;
+
+/**
+ * Validates whether the input is a negative number.
+ *
+ * @author Alexandre Gomes Gaigalas <alexandre@gaigalas.net>
+ * @author Henrique Moody <henriquemoody@gmail.com>
+ * @author Ismael Elias <ismael.esq@hotmail.com>
+ */
+final class Negative extends AbstractRule
 {
+    /**
+     * {@inheritdoc}
+     */
     public function validate($input): bool
     {
+        if (!is_numeric($input)) {
+            return false;
+        }
+
         return $input < 0;
     }
 }

tests/integration/rules/negative.phpt

@@ -0,0 +1,38 @@
+--FILE--
+<?php
+require 'vendor/autoload.php';
+
+use Respect\Validation\Exceptions\NegativeException;
+use Respect\Validation\Exceptions\NestedValidationException;
+use Respect\Validation\Validator as v;
+
+try {
+    v::negative()->check(16);
+} catch (NegativeException $exception) {
+    echo $exception->getMessage().PHP_EOL;
+}
+
+try {
+    v::not(v::negative())->check(-10);
+} catch (NegativeException $exception) {
+    echo $exception->getMessage().PHP_EOL;
+}
+
+try {
+    v::negative()->assert('a');
+} catch (NestedValidationException $exception) {
+    echo $exception->getFullMessage().PHP_EOL;
+}
+
+try {
+    v::not(v::negative())->assert('-144');
+} catch (NestedValidationException $exception) {
+    echo $exception->getFullMessage().PHP_EOL;
+}
+
+?>
+--EXPECTF--
+16 must be negative
+-10 must not be negative
+- "a" must be negative
+- "-144" must not be negative

tests/unit/Rules/NegativeTest.php

@@ -13,65 +13,56 @@ declare(strict_types=1);
 
 namespace Respect\Validation\Rules;
 
-use PHPUnit\Framework\TestCase;
+use Respect\Validation\Test\RuleTestCase;
+use stdClass;
 
 /**
- * @group  rule
+ * @group rule
+ *
  * @covers \Respect\Validation\Rules\Negative
- * @covers \Respect\Validation\Exceptions\NegativeException
+ *
+ * @author Alexandre Gomes Gaigalas <alexandre@gaigalas.net>
+ * @author Gabriel Caruso <carusogabriel34@gmail.com>
+ * @author Henrique Moody <henriquemoody@gmail.com>
+ * @author Ismael Elias <ismael.esq@hotmail.com>
  */
-class NegativeTest extends TestCase
+final class NegativeTest extends RuleTestCase
 {
-    protected $negativeValidator;
-
-    protected function setUp(): void
+    /*
+    * {@inheritdoc}
+    */
+    public function providerForValidInput(): array
     {
-        $this->negativeValidator = new Negative();
-    }
+        $rule = new Negative();
 
-    /**
-     * @dataProvider providerForNegative
-     */
-    public function testNegativeShouldPass($input): void
-    {
-        $this->negativeValidator->assert($input);
-        self::assertTrue($this->negativeValidator->__invoke($input));
-        $this->negativeValidator->check($input);
-    }
-
-    /**
-     * @dataProvider providerForNotNegative
-     * @expectedException \Respect\Validation\Exceptions\NegativeException
-     */
-    public function testNotNegativeNumbersShouldThrowNegativeException($input): void
-    {
-        self::assertFalse($this->negativeValidator->__invoke($input));
-        $this->negativeValidator->assert($input);
-    }
-
-    public function providerForNegative()
-    {
         return [
-            ['-1.44'],
-            [-1e-5],
-            [-10],
+            [$rule, '-1.44'],
+            [$rule, -1e-5],
+            [$rule, -10],
         ];
     }
 
-    public function providerForNotNegative()
+    /*
+    * {@inheritdoc}
+    */
+    public function providerForInvalidInput(): array
     {
+        $rule = new Negative();
+
         return [
-            [''],
-            [0],
-            [-0],
-            [null],
-            ['a'],
-            [' '],
-            ['Foo'],
-            [16],
-            ['165'],
-            [123456],
-            [1e10],
+            [$rule, ''],
+            [$rule, []],
+            [$rule, new stdClass()],
+            [$rule, 0],
+            [$rule, -0],
+            [$rule, null],
+            [$rule, 'a'],
+            [$rule, ' '],
+            [$rule, 'Foo'],
+            [$rule, 16],
+            [$rule, '165'],
+            [$rule, 123456],
+            [$rule, 1e10],
         ];
     }
 }