Enhancement: Extract NewLine value object

src/Format/Format.php

@@ -15,11 +15,6 @@
 
 final class Format implements FormatInterface
 {
-    /**
-     * Constant for a regular expression matching valid new-line character sequence.
-     */
-    private const PATTERN_NEW_LINE = '/^(?>\r\n|\n|\r)$/';
-
     /**
      * @var int
      */
@@ -31,24 +26,24 @@ final class Format implements FormatInterface
     private $indent;
 
     /**
-     * @var bool
+     * @var NewLineInterface
      */
-    private $hasFinalNewLine;
+    private $newLine;
 
     /**
-     * @var string
+     * @var bool
      */
-    private $newLine;
+    private $hasFinalNewLine;
 
     /**
-     * @param int             $jsonEncodeOptions
-     * @param IndentInterface $indent
-     * @param string          $newLine
-     * @param bool            $hasFinalNewLine
+     * @param int              $jsonEncodeOptions
+     * @param IndentInterface  $indent
+     * @param NewLineInterface $newLine
+     * @param bool             $hasFinalNewLine
      *
      * @throws \InvalidArgumentException
      */
-    public function __construct(int $jsonEncodeOptions, IndentInterface $indent, string $newLine, bool $hasFinalNewLine)
+    public function __construct(int $jsonEncodeOptions, IndentInterface $indent, NewLineInterface $newLine, bool $hasFinalNewLine)
     {
         if (0 > $jsonEncodeOptions) {
             throw new \InvalidArgumentException(\sprintf(
@@ -57,13 +52,6 @@ public function __construct(int $jsonEncodeOptions, IndentInterface $indent, str
             ));
         }
 
-        if (1 !== \preg_match(self::PATTERN_NEW_LINE, $newLine)) {
-            throw new \InvalidArgumentException(\sprintf(
-                '"%s" is not a valid new-line character sequence.',
-                $newLine
-            ));
-        }
-
         $this->jsonEncodeOptions = $jsonEncodeOptions;
         $this->indent = $indent;
         $this->newLine = $newLine;
@@ -80,7 +68,7 @@ public function indent(): IndentInterface
         return $this->indent;
     }
 
-    public function newLine(): string
+    public function newLine(): NewLineInterface
     {
         return $this->newLine;
     }
@@ -115,15 +103,8 @@ public function withIndent(IndentInterface $indent): FormatInterface
         return $mutated;
     }
 
-    public function withNewLine(string $newLine): FormatInterface
+    public function withNewLine(NewLineInterface $newLine): FormatInterface
     {
-        if (1 !== \preg_match(self::PATTERN_NEW_LINE, $newLine)) {
-            throw new \InvalidArgumentException(\sprintf(
-                '"%s" is not a valid new-line character sequence.',
-                $newLine
-            ));
-        }
-
         $mutated = clone $this;
 
         $mutated->newLine = $newLine;

src/Format/FormatInterface.php

@@ -19,7 +19,7 @@ public function jsonEncodeOptions(): int;
 
     public function indent(): IndentInterface;
 
-    public function newLine(): string;
+    public function newLine(): NewLineInterface;
 
     public function hasFinalNewLine(): bool;
 
@@ -34,14 +34,7 @@ public function withJsonEncodeOptions(int $jsonEncodeOptions): self;
 
     public function withIndent(IndentInterface $indent): self;
 
-    /**
-     * @param string $newLine
-     *
-     * @throws \InvalidArgumentException
-     *
-     * @return FormatInterface
-     */
-    public function withNewLine(string $newLine): self;
+    public function withNewLine(NewLineInterface $newLine): self;
 
     public function withHasFinalNewLine(bool $hasFinalNewLine): self;
 }

src/Format/Formatter.php

@@ -46,7 +46,7 @@ public function format(string $json, FormatInterface $format): string
         $printed = $this->printer->print(
             $encoded,
             (string) $format->indent(),
-            $format->newLine()
+            (string) $format->newLine()
         );
 
         if (!$format->hasFinalNewLine()) {

src/Format/NewLine.php

@@ -0,0 +1,51 @@
+<?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\Format;
+
+final class NewLine implements NewLineInterface
+{
+    /**
+     * @var string
+     */
+    private $string;
+
+    private function __construct(string $string)
+    {
+        $this->string = $string;
+    }
+
+    public function __toString(): string
+    {
+        return $this->string;
+    }
+
+    /**
+     * @param string $string
+     *
+     * @throws \InvalidArgumentException
+     *
+     * @return NewLineInterface
+     */
+    public static function fromString(string $string): NewLineInterface
+    {
+        if (1 !== \preg_match('/^(?>\r\n|\n|\r)$/', $string)) {
+            throw new \InvalidArgumentException(\sprintf(
+                '"%s" is not a valid new-line character sequence.',
+                $string
+            ));
+        }
+
+        return new self($string);
+    }
+}

src/Format/NewLineInterface.php

@@ -0,0 +1,19 @@
+<?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\Format;
+
+interface NewLineInterface
+{
+    public function __toString(): string;
+}

src/Format/Sniffer.php

@@ -59,13 +59,13 @@ private function indent(string $json): IndentInterface
         );
     }
 
-    private function newLine(string $json): string
+    private function newLine(string $json): NewLineInterface
     {
         if (1 === \preg_match('/(?P<newLine>\r\n|\n|\r)/', $json, $match)) {
-            return $match['newLine'];
+            return NewLine::fromString($match['newLine']);
         }
 
-        return \PHP_EOL;
+        return NewLine::fromString(\PHP_EOL);
     }
 
     private function hasFinalNewLine(string $json): bool