From 950395ec8d00695e3b311a101af19ea81074427e Mon Sep 17 00:00:00 2001
From: Romain Canon <romain.hydrocanon@gmail.com>
Date: Sun, 27 Oct 2024 21:49:11 +0100
Subject: [PATCH] feat: handle `JSON_PRETTY_PRINT` option with the JSON
 normalizer

Formats the JSON with whitespaces and line breaks.

```php
$input = [
    'value' => 'foo',
    'list' => [
        'foo',
        42,
        ['sub']
    ],
    'associative' => [
        'value' => 'foo',
        'sub' => [
            'string' => 'foo',
            'integer' => 42,
        ],
    ],
];

(new \CuyZ\Valinor\MapperBuilder())
    ->normalizer(\CuyZ\Valinor\Normalizer\Format::json())
    ->withOptions(\JSON_PRETTY_PRINT)
    ->normalize($input);

// Result:
// {
//     "value": "foo",
//     "list": [
//         "foo",
//         42,
//         [
//             "sub"
//         ]
//     ],
//     "associative": {
//         "value": "foo",
//         "sub": {
//             "string": "foo",
//             "integer": 42
//         }
//     }
// }
---
 docs/pages/serialization/normalizing-json.md  |  1 +
 src/Normalizer/Formatter/JsonFormatter.php    | 34 +++++++++--
 src/Normalizer/JsonNormalizer.php             |  1 +
 .../Integration/Normalizer/NormalizerTest.php | 61 +++++++++++++++++--
 4 files changed, 86 insertions(+), 11 deletions(-)

diff --git a/docs/pages/serialization/normalizing-json.md b/docs/pages/serialization/normalizing-json.md
index a935d92e..0b931cda 100644
--- a/docs/pages/serialization/normalizing-json.md
+++ b/docs/pages/serialization/normalizing-json.md
@@ -109,6 +109,7 @@ representations ([see official doc for more information]):
 - `JSON_INVALID_UTF8_IGNORE`
 - `JSON_INVALID_UTF8_SUBSTITUTE`
 - `JSON_NUMERIC_CHECK`
+- `JSON_PRETTY_PRINT`
 - `JSON_PRESERVE_ZERO_FRACTION`
 - `JSON_UNESCAPED_LINE_TERMINATORS`
 - `JSON_UNESCAPED_SLASHES`
diff --git a/src/Normalizer/Formatter/JsonFormatter.php b/src/Normalizer/Formatter/JsonFormatter.php
index e7dfe298..33c591b1 100644
--- a/src/Normalizer/Formatter/JsonFormatter.php
+++ b/src/Normalizer/Formatter/JsonFormatter.php
@@ -18,7 +18,6 @@
 use function json_encode;
 
 use const JSON_FORCE_OBJECT;
-use const JSON_THROW_ON_ERROR;
 
 /** @internal */
 final class JsonFormatter implements StreamFormatter
@@ -32,6 +31,11 @@ public function __construct(
     ) {}
 
     public function format(mixed $value): void
+    {
+        $this->formatRecursively($value, 1);
+    }
+
+    private function formatRecursively(mixed $value, int $depth): void
     {
         if (is_null($value)) {
             $this->write('null');
@@ -66,8 +70,14 @@ public function format(mixed $value): void
             $this->write($isList ? '[' : '{');
 
             foreach ($value as $key => $val) {
+                $chunk = '';
+
                 if (! $isFirst) {
-                    $this->write(',');
+                    $chunk = ',';
+                }
+
+                if ($this->jsonEncodingOptions & JSON_PRETTY_PRINT) {
+                    $chunk .= PHP_EOL . str_repeat('    ', $depth);
                 }
 
                 $isFirst = false;
@@ -75,13 +85,27 @@ public function format(mixed $value): void
                 if (! $isList) {
                     $key = json_encode((string)$key, $this->jsonEncodingOptions);
 
-                    $this->write($key . ':');
+                    $chunk .= $key . ':';
+
+                    if ($this->jsonEncodingOptions & JSON_PRETTY_PRINT) {
+                        $chunk .= ' ';
+                    }
                 }
 
-                $this->format($val);
+                $this->write($chunk);
+
+                $this->formatRecursively($val, $depth + 1);
+            }
+
+            $chunk = '';
+
+            if ($this->jsonEncodingOptions & JSON_PRETTY_PRINT) {
+                $chunk = PHP_EOL . str_repeat('    ', $depth - 1);
             }
 
-            $this->write($isList ? ']' : '}');
+            $chunk .= $isList ? ']' : '}';
+
+            $this->write($chunk);
         } else {
             throw new CannotFormatInvalidTypeToJson($value);
         }
diff --git a/src/Normalizer/JsonNormalizer.php b/src/Normalizer/JsonNormalizer.php
index 3ccb8702..2525bd24 100644
--- a/src/Normalizer/JsonNormalizer.php
+++ b/src/Normalizer/JsonNormalizer.php
@@ -43,6 +43,7 @@ final class JsonNormalizer implements Normalizer
     | JSON_INVALID_UTF8_IGNORE
     | JSON_INVALID_UTF8_SUBSTITUTE
     | JSON_NUMERIC_CHECK
+    | JSON_PRETTY_PRINT
     | JSON_PRESERVE_ZERO_FRACTION
     | JSON_UNESCAPED_LINE_TERMINATORS
     | JSON_UNESCAPED_SLASHES
diff --git a/tests/Integration/Normalizer/NormalizerTest.php b/tests/Integration/Normalizer/NormalizerTest.php
index 88e1aa95..6758868d 100644
--- a/tests/Integration/Normalizer/NormalizerTest.php
+++ b/tests/Integration/Normalizer/NormalizerTest.php
@@ -747,6 +747,61 @@ public function getIterator(): Traversable
             'expected array' => [],
             'expected_json' => '{}',
         ];
+
+        yield 'nested array with JSON_PRETTY_PRINT option' => [
+            'input' => [
+                'value' => 'foo',
+                'list' => [
+                    'foo',
+                    42,
+                    ['sub']
+                ],
+                'associative' => [
+                    'value' => 'foo',
+                    'sub' => [
+                        'string' => 'foo',
+                        'integer' => 42,
+                    ],
+                ],
+            ],
+            'expected array' => [
+                'value' => 'foo',
+                'list' => [
+                    'foo',
+                    42,
+                    ['sub']
+                ],
+                'associative' => [
+                    'value' => 'foo',
+                    'sub' => [
+                        'string' => 'foo',
+                        'integer' => 42,
+                    ],
+                ],
+            ],
+            'expected_json' => <<<JSON
+            {
+                "value": "foo",
+                "list": [
+                    "foo",
+                    42,
+                    [
+                        "sub"
+                    ]
+                ],
+                "associative": {
+                    "value": "foo",
+                    "sub": {
+                        "string": "foo",
+                        "integer": 42
+                    }
+                }
+            }
+            JSON,
+            'transformers' => [],
+            'transformerAttributes' => [],
+            'jsonEncodingOptions' => JSON_PRETTY_PRINT,
+        ];
     }
 
     public function test_generator_of_scalar_yields_expected_array(): void
@@ -1176,12 +1231,6 @@ public function test_json_transformer_only_accepts_acceptable_json_options(): vo
     {
         $normalizer = $this->mapperBuilder()->normalizer(Format::json())->withOptions(JSON_PARTIAL_OUTPUT_ON_ERROR);
         self::assertSame(JSON_THROW_ON_ERROR, (fn () => $this->jsonEncodingOptions)->call($normalizer));
-
-        $normalizer = $this->mapperBuilder()->normalizer(Format::json())->withOptions(JSON_PRETTY_PRINT);
-        self::assertSame(JSON_THROW_ON_ERROR, (fn () => $this->jsonEncodingOptions)->call($normalizer));
-
-        $normalizer = $this->mapperBuilder()->normalizer(Format::json())->withOptions(JSON_PARTIAL_OUTPUT_ON_ERROR | JSON_PRETTY_PRINT);
-        self::assertSame(JSON_THROW_ON_ERROR, (fn () => $this->jsonEncodingOptions)->call($normalizer));
     }
 }