Allow Reference for Schema::additionalProperties

adding a ref here was not possible before and resulted in a broken
Schema object.

Author: cebe

src/SpecBaseObject.php

@@ -125,9 +125,9 @@ public function __construct(array $data)
     /**
      * @throws TypeErrorException
      */
-    private function instantiate($type, $data)
+    protected function instantiate($type, $data)
     {
-        if ($data instanceof $type) {
+        if ($data instanceof $type || $data instanceof Reference) {
             return $data;
         }
 

src/spec/Schema.php

@@ -136,21 +136,13 @@ public function __construct(array $data)
     {
         if (isset($data['additionalProperties'])) {
             if (is_array($data['additionalProperties'])) {
-                try {
-                    $data['additionalProperties'] = new Schema($data['additionalProperties']);
-                } catch (\TypeError $e) {
-                    throw new TypeErrorException(
-                        "Unable to instantiate Schema Object with data '" . print_r($data['additionalProperties'], true) . "'",
-                        $e->getCode(),
-                        $e
-                    );
-                }
-            } elseif (!($data['additionalProperties'] instanceof Schema || is_bool($data['additionalProperties']))) {
+                $data['additionalProperties'] = $this->instantiate(Schema::class, $data['additionalProperties']);
+            } elseif (!($data['additionalProperties'] instanceof Schema || $data['additionalProperties'] instanceof Reference || is_bool($data['additionalProperties']))) {
                 $givenType = gettype($data['additionalProperties']);
                 if ($givenType === 'object') {
                     $givenType = get_class($data['additionalProperties']);
                 }
-                throw new TypeErrorException(sprintf('Schema::$additionalProperties MUST be either array, boolean or a Schema object, "%s" given', $givenType));
+                throw new TypeErrorException(sprintf('Schema::$additionalProperties MUST be either boolean or a Schema/Reference object, "%s" given', $givenType));
             }
         }
         parent::__construct($data);

tests/spec/SchemaTest.php

@@ -167,9 +167,9 @@ public function badSchemaProvider()
         yield [['properties' => ['a' => false]], 'Unable to instantiate cebe\openapi\spec\Schema Object with data \'\''];
         yield [['properties' => ['a' => new stdClass()]], "Unable to instantiate cebe\openapi\spec\Schema Object with data 'stdClass Object\n(\n)\n'"];
 
-        yield [['additionalProperties' => 'foo'], 'Schema::$additionalProperties MUST be either array, boolean or a Schema object, "string" given'];
-        yield [['additionalProperties' => 42], 'Schema::$additionalProperties MUST be either array, boolean or a Schema object, "integer" given'];
-        yield [['additionalProperties' => new stdClass()], 'Schema::$additionalProperties MUST be either array, boolean or a Schema object, "stdClass" given'];
+        yield [['additionalProperties' => 'foo'], 'Schema::$additionalProperties MUST be either boolean or a Schema/Reference object, "string" given'];
+        yield [['additionalProperties' => 42], 'Schema::$additionalProperties MUST be either boolean or a Schema/Reference object, "integer" given'];
+        yield [['additionalProperties' => new stdClass()], 'Schema::$additionalProperties MUST be either boolean or a Schema/Reference object, "stdClass" given'];
         // The last one can be supported in future, but now SpecBaseObjects::__construct() requires array explicitly
     }
 
@@ -283,4 +283,41 @@ public function testSchemaProperties()
             $this->assertEquals($defaultValue, $schema->$property, "testing property '$property'");
         }
     }
+
+    public function testRefAdditionalProperties()
+    {
+        $json = <<<'JSON'
+{
+  "components": {
+    "schemas": {
+      "booleanProperties": {
+        "type": "boolean"
+      },
+      "person": {
+        "type": "object",
+        "properties": {
+          "name": {
+            "type": "string"
+          }
+        },
+        "additionalProperties": {"$ref": "#/components/schemas/booleanProperties"}
+      }
+    }
+  }
+}
+JSON;
+        $openApi = Reader::readFromJson($json);
+        $this->assertInstanceOf(Schema::class, $booleanProperties = $openApi->components->schemas['booleanProperties']);
+        $this->assertInstanceOf(Schema::class, $person = $openApi->components->schemas['person']);
+
+        $this->assertEquals('boolean', $booleanProperties->type);
+        $this->assertInstanceOf(Reference::class, $person->additionalProperties);
+
+        $this->assertInstanceOf(Schema::class, $refResolved = $person->additionalProperties->resolve(new ReferenceContext($openApi, 'tmp://openapi.yaml')));
+
+        $this->assertEquals('boolean', $refResolved->type);
+
+        $schema = new Schema(['additionalProperties' => new Reference(['$ref' => '#/here'], Schema::class)]);
+        $this->assertInstanceOf(Reference::class, $schema->additionalProperties);
+    }
 }