Enhancement: Implement JsonEncodeNormalizer

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\JsonEncodeNormalizer`](#jsonencodenormalizer)
 * [`Localheinz\Json\Normalizer\NoFinalNewLineNormalizer`](#nofinalnewlinenormalizer)
 
 :bulb: All of these normalizers implement the `Localheinz\Json\Normalizer\NormalizerInterface`. 
@@ -71,6 +72,32 @@ $normalized = $normalizer->normalize($json);
 
 The normalized version will now be indented with 2 spaces.
 
+### `JsonEncodeNormalizer`
+
+If you need to adjust the encoding of a JSON file, you can use the `JsonEncodeNormalizer`.
+
+```php
+use Localheinz\Json\Normalizer;
+
+$json = <<<'JSON'
+{
+    "name": "Andreas Möller",
+    "url": "https://localheinz.com"
+}
+JSON;
+
+$jsonEncodeOptions = JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES;
+
+$normalizer = new Normalizer\JsonEncodeNormalizer($jsonEncodeOptions);
+
+$normalized = $normalizer->normalize($json);
+```
+
+The normalized version will now be encoded with `$jsonEncodeOptions`.
+
+:bulb: For reference, see [`json_encode()`](http://php.net/manual/en/function.json-encode.php) 
+and the corresponding [JSON constants](http://php.net/manual/en/json.constants.php).
+
 ### `NoFinalNewLineNormalizer`
 
 If you want to ensure that a JSON file does not have a final new line, you can use the `FinalNewLineNormalizer`.

src/JsonEncodeNormalizer.php

@@ -0,0 +1,53 @@
+<?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 JsonEncodeNormalizer implements NormalizerInterface
+{
+    /**
+     * @var int
+     */
+    private $jsonEncodeOptions;
+
+    /**
+     * @param int $jsonEncodeOptions
+     *
+     * @throws \InvalidArgumentException
+     */
+    public function __construct(int $jsonEncodeOptions)
+    {
+        if (0 > $jsonEncodeOptions) {
+            throw new \InvalidArgumentException(\sprintf(
+                '"%s" is not valid options for json_encode().',
+                $jsonEncodeOptions
+            ));
+        }
+        $this->jsonEncodeOptions = $jsonEncodeOptions;
+    }
+
+    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.',
+                $json
+            ));
+        }
+
+        return \json_encode(
+            \json_decode($json),
+            $this->jsonEncodeOptions
+        );
+    }
+}

test/Unit/JsonEncodeNormalizerTest.php

@@ -0,0 +1,117 @@
+<?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\JsonEncodeNormalizer;
+
+final class JsonEncodeNormalizerTest extends AbstractNormalizerTestCase
+{
+    public function testConstructorRejectsInvalidJsonEncodeOptions()
+    {
+        $jsonEncodeOptions = -1;
+
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage(\sprintf(
+            '"%s" is not valid options for json_encode().',
+            $jsonEncodeOptions
+        ));
+
+        new JsonEncodeNormalizer($jsonEncodeOptions);
+    }
+
+    /**
+     * @dataProvider providerJsonEncodeOptions
+     *
+     * @param int $jsonEncodeOptions
+     */
+    public function testNormalizeDecodesAndEncodesJsonWithJsonEncodeOptions(int $jsonEncodeOptions)
+    {
+        $json = <<<'JSON'
+{
+  "name": "Andreas M\u00f6ller",
+  "url": "https:\/\/github.com\/localheinz\/json-normalizer",
+  "string-apostroph": "'",
+  "string-numeric": "9000",
+  "string-quote": "\"",
+  "string-tag": "<p>"
+}
+JSON;
+        $normalizer = new JsonEncodeNormalizer($jsonEncodeOptions);
+
+        $encoded = \json_encode(
+            \json_decode($json),
+            $jsonEncodeOptions
+        );
+
+        $this->assertSame($encoded, $normalizer->normalize($json));
+    }
+
+    public function providerJsonEncodeOptions(): \Generator
+    {
+        /**
+         * Could add more, but the idea counts.
+         */
+        $jsonEncodeFlags = [
+            JSON_HEX_APOS,
+            JSON_HEX_QUOT,
+            JSON_HEX_TAG,
+            JSON_NUMERIC_CHECK,
+            JSON_UNESCAPED_SLASHES,
+            JSON_UNESCAPED_UNICODE,
+        ];
+
+        $combinations = $this->combinations($jsonEncodeFlags);
+
+        foreach ($combinations as $combination) {
+            $jsonEncodeOptions = \array_reduce(
+                $combination,
+                function (int $jsonEncodeFlag, int $jsonEncodeOptions) {
+                    $jsonEncodeOptions |= $jsonEncodeFlag;
+
+                    return $jsonEncodeOptions;
+                },
+                0
+            );
+
+            yield [
+                $jsonEncodeOptions,
+            ];
+        }
+    }
+
+    /**
+     * @see https://docstore.mik.ua/orelly/webprog/pcook/ch04_25.htm
+     *
+     * @param array $elements
+     *
+     * @return array
+     */
+    private function combinations(array $elements): array
+    {
+        $combinations = [[]];
+
+        foreach ($elements as $element) {
+            foreach ($combinations as $combination) {
+                $combinations[] = \array_merge(
+                    [
+                        $element,
+                    ],
+                    $combination
+                );
+            }
+        }
+
+        return $combinations;
+    }
+}