Enhancement: Implement NoFinalNewLineNormalizer

README.md

@@ -21,6 +21,7 @@ This package comes with the following normalizers:
 
 * [`Localheinz\Json\Normalizer\FinalNewLineNormalizer`](#finalnewlinenormalizer)
 * [`Localheinz\Json\Normalizer\IndentNormalizer`](#indentnormalizer)
+* [`Localheinz\Json\Normalizer\NoFinalNewLineNormalizer`](#nofinalnewlinenormalizer)
 
 :bulb: All of these normalizers implement the `Localheinz\Json\Normalizer\NormalizerInterface`. 
 
@@ -70,6 +71,29 @@ $normalized = $normalizer->normalize($json);
 
 The normalized version will now be indented with 2 spaces.
 
+### `NoFinalNewLineNormalizer`
+
+If you want to ensure that a JSON file does not have a final new line, you can use the `FinalNewLineNormalizer`.
+
+```php
+use Localheinz\Json\Normalizer;
+
+$json = <<<'JSON'
+{
+    "name": "Andreas Möller",
+    "url": "https://localheinz.com"
+}
+
+
+JSON;
+
+$normalizer = new Normalizer\NoFinalNewLineNormalizer();
+
+$normalized = $normalizer->normalize($json);
+```
+
+The normalized version will not have a final new line now.
+
 ## Contributing
 
 Please have a look at [`CONTRIBUTING.md`](.github/CONTRIBUTING.md).

src/NoFinalNewLineNormalizer.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2018 Andreas Möller.
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/localheinz/json-normalizer
+ */
+
+namespace Localheinz\Json\Normalizer;
+
+final class NoFinalNewLineNormalizer implements NormalizerInterface
+{
+    public function normalize(string $json): string
+    {
+        if (null === \json_decode($json) && JSON_ERROR_NONE !== \json_last_error()) {
+            throw new \InvalidArgumentException(\sprintf(
+                '"%s" is not valid JSON.',
+                $json
+            ));
+        }
+
+        return \rtrim($json);
+    }
+}

test/Unit/NoFinalNewLineNormalizerTest.php

@@ -0,0 +1,82 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2018 Andreas Möller.
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/localheinz/json-normalizer
+ */
+
+namespace Localheinz\Json\Normalizer\Test\Unit;
+
+use Localheinz\Json\Normalizer\NoFinalNewLineNormalizer;
+use Localheinz\Json\Normalizer\NormalizerInterface;
+use Localheinz\Test\Util\Helper;
+use PHPUnit\Framework;
+
+final class NoFinalNewLineNormalizerTest extends Framework\TestCase
+{
+    use Helper;
+
+    public function testImplementsNormalizerInterface()
+    {
+        $this->assertClassImplementsInterface(NormalizerInterface::class, NoFinalNewLineNormalizer::class);
+    }
+
+    public function testNormalizeRejectsInvalidJson()
+    {
+        $json = $this->faker()->realText();
+
+        $normalizer = new NoFinalNewLineNormalizer();
+
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage(\sprintf(
+            '"%s" is not valid JSON.',
+            $json
+        ));
+
+        $normalizer->normalize($json);
+    }
+
+    /**
+     * @dataProvider providerWhitespace
+     *
+     * @param string $whitespace
+     */
+    public function testNormalizeRemovesAllWhitespaceFromEndOfJson(string $whitespace)
+    {
+        $json = <<<'JSON'
+{
+    "name": "Andreas Möller",
+    "url": "https://localheinz.com"
+}
+JSON;
+        $json .= $whitespace;
+
+        $normalized = \rtrim($json);
+
+        $normalizer = new NoFinalNewLineNormalizer();
+
+        $this->assertSame($normalized, $normalizer->normalize($json));
+    }
+
+    public function providerWhitespace()
+    {
+        $values = [
+            '',
+            ' ',
+            "\t",
+            PHP_EOL,
+        ];
+
+        foreach ($values as $value) {
+            yield [
+                $value,
+            ];
+        }
+    }
+}