[TypeInfo] Add Type::traverse() method

mtarld · fabpot · commit 65c7e13e964d · 2025-03-24T09:24:09.000+01:00
diff --git a/src/Symfony/Component/TypeInfo/CHANGELOG.md b/src/Symfony/Component/TypeInfo/CHANGELOG.md
@@ -11,6 +11,7 @@ CHANGELOG
  * Add type alias support in `TypeContext` and `StringTypeResolver`
  * Add `CollectionType::mergeCollectionValueTypes()` method
  * Add `ArrayShapeType` to represent the exact shape of an array
+ * Add `Type::traverse()` method
 
 7.2
 ---
diff --git a/src/Symfony/Component/TypeInfo/Tests/TypeTest.php b/src/Symfony/Component/TypeInfo/Tests/TypeTest.php
@@ -34,4 +34,44 @@ public function testIsNullable()
 
         $this->assertFalse(Type::int()->isNullable());
     }
+
+    public function testTraverse()
+    {
+        $this->assertEquals([Type::int()], iterator_to_array(Type::int()->traverse()));
+
+        $this->assertEquals(
+            [Type::union(Type::int(), Type::string()), Type::int(), Type::string()],
+            iterator_to_array(Type::union(Type::int(), Type::string())->traverse()),
+        );
+        $this->assertEquals(
+            [Type::union(Type::int(), Type::string())],
+            iterator_to_array(Type::union(Type::int(), Type::string())->traverse(traverseComposite: false)),
+        );
+
+        $this->assertEquals(
+            [Type::generic(Type::object(\Traversable::class), Type::string()), Type::object(\Traversable::class)],
+            iterator_to_array(Type::generic(Type::object(\Traversable::class), Type::string())->traverse()),
+        );
+        $this->assertEquals(
+            [Type::generic(Type::object(\Traversable::class), Type::string())],
+            iterator_to_array(Type::generic(Type::object(\Traversable::class), Type::string())->traverse(traverseWrapped: false)),
+        );
+
+        $this->assertEquals(
+            [Type::nullable(Type::int()), Type::int(), Type::null()],
+            iterator_to_array(Type::nullable(Type::int())->traverse()),
+        );
+        $this->assertEquals(
+            [Type::nullable(Type::int()), Type::int()],
+            iterator_to_array(Type::nullable(Type::int())->traverse(traverseComposite: false)),
+        );
+        $this->assertEquals(
+            [Type::nullable(Type::int()), Type::int(), Type::null()],
+            iterator_to_array(Type::nullable(Type::int())->traverse(traverseWrapped: false)),
+        );
+        $this->assertEquals(
+            [Type::nullable(Type::int())],
+            iterator_to_array(Type::nullable(Type::int())->traverse(traverseComposite: false, traverseWrapped: false)),
+        );
+    }
 }
diff --git a/src/Symfony/Component/TypeInfo/Type.php b/src/Symfony/Component/TypeInfo/Type.php
@@ -76,4 +76,27 @@ public function accepts(mixed $value): bool
 
         return $this->isSatisfiedBy($specification);
     }
+
+    /**
+     * Traverses the whole type tree.
+     *
+     * @return iterable<self>
+     */
+    public function traverse(bool $traverseComposite = true, bool $traverseWrapped = true): iterable
+    {
+        yield $this;
+
+        if ($this instanceof CompositeTypeInterface && $traverseComposite) {
+            foreach ($this->getTypes() as $type) {
+                yield $type;
+            }
+
+            // prevent yielding twice when having a type that is both composite and wrapped
+            return;
+        }
+
+        if ($this instanceof WrappingTypeInterface && $traverseWrapped) {
+            yield $this->getWrappedType();
+        }
+    }
 }
