Fix iterator return types (#1123)

Co-authored-by: Hugo Hamon <hhamon@users.noreply.github.com>

src/Definition/FlagBag.php

@@ -17,6 +17,7 @@
 use Countable;
 use IteratorAggregate;
 use function Nelmio\Alice\deep_clone;
+use Traversable;
 
 /**
  * Collection of flags.
@@ -94,7 +95,7 @@ public function getKey(): string
         return $this->key;
     }
 
-    public function getIterator(): ArrayIterator
+    public function getIterator(): Traversable
     {
         return new ArrayIterator(array_values($this->flags));
     }

src/Definition/MethodCallBag.php

@@ -16,6 +16,7 @@
 use ArrayIterator;
 use Countable;
 use IteratorAggregate;
+use Traversable;
 
 final class MethodCallBag implements IteratorAggregate, Countable
 {
@@ -51,7 +52,7 @@ public function isEmpty(): bool
         return [] === $this->methodCalls;
     }
 
-    public function getIterator(): ArrayIterator
+    public function getIterator(): Traversable
     {
         return new ArrayIterator(array_values($this->methodCalls));
     }

src/Definition/PropertyBag.php

@@ -16,6 +16,7 @@
 use ArrayIterator;
 use Countable;
 use IteratorAggregate;
+use Traversable;
 
 final class PropertyBag implements IteratorAggregate, Countable
 {
@@ -51,7 +52,7 @@ public function isEmpty(): bool
         return [] === $this->properties;
     }
 
-    public function getIterator(): ArrayIterator
+    public function getIterator(): Traversable
     {
         return new ArrayIterator(array_values($this->properties));
     }

src/FixtureBag.php

@@ -17,6 +17,7 @@
 use IteratorAggregate;
 use Nelmio\Alice\Throwable\Exception\FixtureNotFoundException;
 use Nelmio\Alice\Throwable\Exception\FixtureNotFoundExceptionFactory;
+use Traversable;
 
 /**
  * Value object containing a list of fixtures.
@@ -85,7 +86,7 @@ public function get(string $id): FixtureInterface
         throw FixtureNotFoundExceptionFactory::create($id);
     }
 
-    public function getIterator(): ArrayIterator
+    public function getIterator(): Traversable
     {
         return new ArrayIterator($this->fixtures);
     }

src/ObjectBag.php

@@ -21,6 +21,7 @@
 use Nelmio\Alice\Throwable\Exception\InvalidArgumentExceptionFactory;
 use Nelmio\Alice\Throwable\Exception\ObjectNotFoundException;
 use Nelmio\Alice\Throwable\Exception\ObjectNotFoundExceptionFactory;
+use Traversable;
 
 /**
  * Value object containing a list of objects.
@@ -121,8 +122,8 @@ public function count(): int
     {
         return count($this->objects);
     }
-    
-    public function getIterator(): ArrayIterator
+
+    public function getIterator(): Traversable
     {
         return new ArrayIterator($this->objects);
     }

src/ParameterBag.php

@@ -18,6 +18,7 @@
 use IteratorAggregate;
 use Nelmio\Alice\Throwable\Exception\ParameterNotFoundException;
 use Nelmio\Alice\Throwable\Exception\ParameterNotFoundExceptionFactory;
+use Traversable;
 
 /**
  * Value object containing a list of parameters.
@@ -78,7 +79,7 @@ public function get(string $key)
         throw ParameterNotFoundExceptionFactory::create($key);
     }
 
-    public function getIterator(): ArrayIterator
+    public function getIterator(): Traversable
     {
         return new ArrayIterator($this->parameters);
     }