[attributes] add support for class constants

src/Analysers/AttributeAnnotationFactory.php

@@ -74,6 +74,21 @@ public function build(\Reflector $reflector, Context $context): array
  }
  }
  }
+
+ if ($reflector instanceof \ReflectionClass) {
+ foreach ($reflector->getReflectionConstants() as $rc) {
+ foreach ($rc->getAttributes(Property::class) as $attribute) {
+ $instance = $attribute->newInstance();
+ if (Generator::isDefault($instance->property)) {
+ $instance->property = $rc->getName();
+ }
+ if (Generator::isDefault($instance->type)) {
+ $instance->const = $rc->getValue();
+ }
+ $annotations[] = $instance;
+ }
+ }
+ }
  } finally {
  Generator::$context = null;
  }

src/Annotations/Schema.php

@@ -336,6 +336,8 @@ class Schema extends AbstractAnnotation
 
  /**
  * http:https://json-schema.org/latest/json-schema-validation.html#rfc.section.6.24.
+ *
+ * @var string
  */
  public $const = Generator::UNDEFINED;
 
@@ -362,6 +364,7 @@ class Schema extends AbstractAnnotation
  'allOf' => '[' . Schema::class . ']',
  'oneOf' => '[' . Schema::class . ']',
  'anyOf' => '[' . Schema::class . ']',
+ 'const' => 'string',
  ];
 
  /**

src/Attributes/Property.php

@@ -8,7 +8,7 @@
 
 use OpenApi\Generator;
 
-#[\Attribute(\Attribute::TARGET_METHOD | \Attribute::TARGET_PROPERTY | \Attribute::TARGET_PARAMETER)]
+#[\Attribute(\Attribute::TARGET_METHOD | \Attribute::TARGET_PROPERTY | \Attribute::TARGET_PARAMETER | \Attribute::TARGET_CLASS_CONSTANT)]
 class Property extends \OpenApi\Annotations\Property
 {
  /**

src/Attributes/Schema.php

@@ -40,6 +40,7 @@ public function __construct(
  ?int $minItems = null,
  ?bool $uniqueItems = null,
  ?string $pattern = null,
+ ?string $const = null,
  ?array $enum = null,
  ?Discriminator $discriminator = null,
  ?bool $readOnly = null,
@@ -78,6 +79,7 @@ public function __construct(
  'minItems' => $minItems ?? Generator::UNDEFINED,
  'uniqueItems' => $uniqueItems ?? Generator::UNDEFINED,
  'pattern' => $pattern ?? Generator::UNDEFINED,
+ 'const' => $const ?? Generator::UNDEFINED,
  'enum' => $enum ?? Generator::UNDEFINED,
  'readOnly' => $readOnly ?? Generator::UNDEFINED,
  'writeOnly' => $writeOnly ?? Generator::UNDEFINED,

src/Generator.php

@@ -191,6 +191,7 @@ public function getProcessors(): array
  new Processors\MergeXmlContent(),
  new Processors\OperationId(),
  new Processors\CleanUnmerged(),
+ new Processors\BackportConstants(),
  ];
  }
 

src/Processors/BackportConstants.php

@@ -0,0 +1,36 @@
+<?php declare(strict_types=1);
+
+/**
+ * @license Apache 2.0
+ */
+
+namespace OpenApi\Processors;
+
+use OpenApi\Analysis;
+use OpenApi\Annotations\OpenApi;
+use OpenApi\Annotations\Property as AnnotationSchema;
+use OpenApi\Attributes\Property as AttributeSchema;
+use OpenApi\Generator;
+
+/**
+ * Transform const keywords to enum in OpenApi versions < 3.1.0.
+ */
+class BackportConstants
+{
+ public function __invoke(Analysis $analysis)
+ {
+ /** @var AnnotationSchema[] $schemas */
+ $schemas = $analysis->getAnnotationsOfType([AnnotationSchema::class, AttributeSchema::class], true);
+
+ foreach ($schemas as $schema) {
+ if (Generator::isDefault($schema->const)) {
+ continue;
+ }
+
+ if (version_compare($analysis->context->version, OpenApi::VERSION_3_1_0, '<')) {
+ $schema->enum = [$schema->const];
+ $schema->const = Generator::UNDEFINED;
+ }
+ }
+ }
+}