[Yaml] Add support for dumping null as an empty string by using the Yaml::DUMP_NULL_AS_EMPTY flag

alexandre-daubois · alexandre-daubois · commit 2fa4bc614b29 · 2024-09-11T12:53:05.000+02:00
diff --git a/src/Symfony/Component/Yaml/CHANGELOG.md b/src/Symfony/Component/Yaml/CHANGELOG.md
@@ -5,6 +5,7 @@ CHANGELOG
 ---
 
  * Deprecate parsing duplicate mapping keys whose value is `null`
+ * Add support for dumping `null` as an empty string by using the `Yaml::DUMP_NULL_AS_EMPTY` flag
 
 7.1
 ---
diff --git a/src/Symfony/Component/Yaml/Dumper.php b/src/Symfony/Component/Yaml/Dumper.php
@@ -46,6 +46,10 @@ public function __construct(int $indentation = 4)
      */
     public function dump(mixed $input, int $inline = 0, int $indent = 0, int $flags = 0): string
     {
+        if ($flags & Yaml::DUMP_NULL_AS_TILDE && $flags & Yaml::DUMP_NULL_AS_EMPTY) {
+            throw new \InvalidArgumentException('The Yaml::DUMP_NULL_AS_TILDE and Yaml::DUMP_NULL_AS_EMPTY flags cannot be used together.');
+        }
+
         $output = '';
         $prefix = $indent ? str_repeat(' ', $indent) : '';
         $dumpObjectAsInlineMap = true;
diff --git a/src/Symfony/Component/Yaml/Inline.php b/src/Symfony/Component/Yaml/Inline.php
@@ -259,6 +259,10 @@ private static function dumpNull(int $flags): string
             return '~';
         }
 
+        if (Yaml::DUMP_NULL_AS_EMPTY & $flags) {
+            return '';
+        }
+
         return 'null';
     }
 
diff --git a/src/Symfony/Component/Yaml/Tests/DumperTest.php b/src/Symfony/Component/Yaml/Tests/DumperTest.php
@@ -853,6 +853,11 @@ public function testDumpNullAsTilde()
         $this->assertSame('{ foo: ~ }', $this->dumper->dump(['foo' => null], 0, 0, Yaml::DUMP_NULL_AS_TILDE));
     }
 
+    public function testDumpNullAsEmpty()
+    {
+        $this->assertSame('{ foo:  }', $this->dumper->dump(['foo' => null], 0, 0, Yaml::DUMP_NULL_AS_EMPTY));
+    }
+
     /**
      * @dataProvider getNumericKeyData
      */
@@ -1012,6 +1017,14 @@ private function assertSameData($expected, $actual)
             var_export($actual, true)
         );
     }
+
+    public function testUseDumpAsTildeAndDumpAsEmptyFlagsTogether()
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('The Yaml::DUMP_NULL_AS_TILDE and Yaml::DUMP_NULL_AS_EMPTY flags cannot be used together.');
+
+        $this->dumper->dump(['foo' => null], 0, 0, Yaml::DUMP_NULL_AS_TILDE | Yaml::DUMP_NULL_AS_EMPTY);
+    }
 }
 
 class A
diff --git a/src/Symfony/Component/Yaml/Yaml.php b/src/Symfony/Component/Yaml/Yaml.php
@@ -35,6 +35,7 @@ class Yaml
     public const DUMP_EMPTY_ARRAY_AS_SEQUENCE = 1024;
     public const DUMP_NULL_AS_TILDE = 2048;
     public const DUMP_NUMERIC_KEY_AS_STRING = 4096;
+    public const DUMP_NULL_AS_EMPTY = 8192;
 
     /**
      * Parses a YAML file into a PHP value.

Original file line number	Diff line number	Diff line change
`@@ -259,6 +259,10 @@ private static function dumpNull(int $flags): string`
`259`	`259`	`return '~';`
`260`	`260`	`}`
`261`	`261`
	`262`	`+ if (Yaml::DUMP_NULL_AS_EMPTY & $flags) {`
	`263`	`+ return '';`
	`264`	`+ }`
	`265`	`+`
`262`	`266`	`return 'null';`
`263`	`267`	`}`
`264`	`268`