[Yaml] Add support for !php/enum *->value syntax

src/Symfony/Component/Yaml/CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+6.2
+---
+
+ * Add support for `!php/enum` and `!php/enum *->value`
+
 6.1
 ---
 

src/Symfony/Component/Yaml/Inline.php

@@ -432,7 +432,7 @@ private static function parseMapping(string $mapping, int $flags, int &$i = 0, a
                 throw new ParseException('Missing mapping key.', self::$parsedLineNumber + 1, $mapping);
             }
 
-            if ('!php/const' === $key) {
+            if ('!php/const' === $key || '!php/enum' === $key) {
                 $key .= ' '.self::parseScalar($mapping, $flags, [':'], $i, false);
                 $key = self::evaluateScalar($key, $flags);
             }
@@ -623,6 +623,40 @@ private static function evaluateScalar(string $scalar, int $flags, array &$refer
                             throw new ParseException(sprintf('The string "%s" could not be parsed as a constant. Did you forget to pass the "Yaml::PARSE_CONSTANT" flag to the parser?', $scalar), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
                         }
 
+                        return null;
+                    case str_starts_with($scalar, '!php/enum'):
+                        if (self::$constantSupport) {
+                            if (!isset($scalar[11])) {
+                                throw new ParseException('Missing value for tag "!php/enum".', self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
+                            }
+
+                            $i = 0;
+                            $enum = self::parseScalar(substr($scalar, 10), 0, null, $i, false);
+                            if ($useValue = str_ends_with($enum, '->value')) {
+                                $enum = substr($enum, 0, -7);
+                            }
+                            if (!\defined($enum)) {
+                                throw new ParseException(sprintf('The enum "%s" is not defined.', $enum), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
+                            }
+
+                            $value = \constant($enum);
+
+                            if (!$value instanceof \UnitEnum) {
+                                throw new ParseException(sprintf('The string "%s" is not the name of a valid enum.', $enum), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
+                            }
+                            if (!$useValue) {
+                                return $value;
+                            }
+                            if (!$value instanceof \BackedEnum) {
+                                throw new ParseException(sprintf('The enum "%s" defines no value next to its name.', $enum), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
+                            }
+
+                            return $value->value;
+                        }
+                        if (self::$exceptionOnInvalidType) {
+                            throw new ParseException(sprintf('The string "%s" could not be parsed as an enum. Did you forget to pass the "Yaml::PARSE_CONSTANT" flag to the parser?', $scalar), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
+                        }
+
                         return null;
                     case str_starts_with($scalar, '!!float '):
                         return (float) substr($scalar, 8);
@@ -703,7 +737,7 @@ private static function parseTag(string $value, int &$i, int $flags): ?string
         }
 
         // Is followed by a scalar and is a built-in tag
-        if ('' !== $tag && (!isset($value[$nextOffset]) || !\in_array($value[$nextOffset], ['[', '{'], true)) && ('!' === $tag[0] || 'str' === $tag || 'php/const' === $tag || 'php/object' === $tag)) {
+        if ('' !== $tag && (!isset($value[$nextOffset]) || !\in_array($value[$nextOffset], ['[', '{'], true)) && ('!' === $tag[0] || \in_array($tag, ['str', 'php/const', 'php/enum', 'php/object'], true))) {
             // Manage in {@link self::evaluateScalar()}
             return null;
         }

src/Symfony/Component/Yaml/Tests/Fixtures/FooBackedEnum.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Symfony\Component\Yaml\Tests\Fixtures;
+
+enum FooBackedEnum: string
+{
+    case BAR = 'bar';
+}

src/Symfony/Component/Yaml/Tests/InlineTest.php

@@ -15,6 +15,7 @@
 use Symfony\Component\Yaml\Exception\ParseException;
 use Symfony\Component\Yaml\Inline;
 use Symfony\Component\Yaml\Tag\TaggedValue;
+use Symfony\Component\Yaml\Tests\Fixtures\FooBackedEnum;
 use Symfony\Component\Yaml\Tests\Fixtures\FooUnitEnum;
 use Symfony\Component\Yaml\Yaml;
 
@@ -72,13 +73,45 @@ public function testParsePhpConstantThrowsExceptionWhenUndefined()
         Inline::parse('!php/const WRONG_CONSTANT', Yaml::PARSE_CONSTANT);
     }
 
+    public function testParsePhpEnumThrowsExceptionWhenUndefined()
+    {
+        $this->expectException(ParseException::class);
+        $this->expectExceptionMessage('The enum "SomeEnum::Foo" is not defined');
+        Inline::parse('!php/enum SomeEnum::Foo', Yaml::PARSE_CONSTANT);
+    }
+
+    public function testParsePhpEnumThrowsExceptionWhenNotAnEnum()
+    {
+        $this->expectException(ParseException::class);
+        $this->expectExceptionMessage('The string "PHP_INT_MAX" is not the name of a valid enum');
+        Inline::parse('!php/enum PHP_INT_MAX', Yaml::PARSE_CONSTANT);
+    }
+
+    public function testParsePhpEnumThrowsExceptionWhenNotBacked()
+    {
+        $this->expectException(ParseException::class);
+        $this->expectExceptionMessage('The enum "Symfony\Component\Yaml\Tests\Fixtures\FooUnitEnum::BAR" defines no value next to its name');
+        Inline::parse('!php/enum Symfony\Component\Yaml\Tests\Fixtures\FooUnitEnum::BAR->value', Yaml::PARSE_CONSTANT);
+    }
+
     public function testParsePhpConstantThrowsExceptionOnInvalidType()
     {
+        $this->assertNull(Inline::parse('!php/const PHP_INT_MAX'));
+
         $this->expectException(ParseException::class);
         $this->expectExceptionMessageMatches('#The string "!php/const PHP_INT_MAX" could not be parsed as a constant.*#');
         Inline::parse('!php/const PHP_INT_MAX', Yaml::PARSE_EXCEPTION_ON_INVALID_TYPE);
     }
 
+    public function testParsePhpEnumThrowsExceptionOnInvalidType()
+    {
+        $this->assertNull(Inline::parse('!php/enum SomeEnum::Foo'));
+
+        $this->expectException(ParseException::class);
+        $this->expectExceptionMessageMatches('#The string "!php/enum SomeEnum::Foo" could not be parsed as an enum.*#');
+        Inline::parse('!php/enum SomeEnum::Foo', Yaml::PARSE_EXCEPTION_ON_INVALID_TYPE);
+    }
+
     /**
      * @dataProvider getTestsForDump
      */
@@ -589,6 +622,16 @@ public function testDumpUnitEnum()
         $this->assertSame("!php/const Symfony\Component\Yaml\Tests\Fixtures\FooUnitEnum::BAR", Inline::dump(FooUnitEnum::BAR));
     }
 
+    public function testParseUnitEnum()
+    {
+        $this->assertSame(FooUnitEnum::BAR, Inline::parse("!php/enum Symfony\Component\Yaml\Tests\Fixtures\FooUnitEnum::BAR", Yaml::PARSE_CONSTANT));
+    }
+
+    public function testParseBackedEnumValue()
+    {
+        $this->assertSame(FooBackedEnum::BAR->value, Inline::parse("!php/enum Symfony\Component\Yaml\Tests\Fixtures\FooBackedEnum::BAR->value", Yaml::PARSE_CONSTANT));
+    }
+
     public function getDateTimeDumpTests()
     {
         $tests = [];
@@ -818,6 +861,17 @@ public function testPhpConstTagWithEmptyValue(string $value)
         Inline::parse($value, Yaml::PARSE_CONSTANT);
     }
 
+    /**
+     * @dataProvider phpConstTagWithEmptyValueProvider
+     */
+    public function testPhpEnumTagWithEmptyValue(string $value)
+    {
+        $this->expectException(ParseException::class);
+        $this->expectExceptionMessage('Missing value for tag "!php/enum" at line 1 (near "!php/enum").');
+
+        Inline::parse(str_replace('!php/const', '!php/enum', $value), Yaml::PARSE_CONSTANT);
+    }
+
     public function phpConstTagWithEmptyValueProvider()
     {
         return [