Proposal to improve consistency of is_iterable() and isIterable Reflection class method with what foreach actually expects

Zend/zend_API.c

@@ -4807,14 +4807,8 @@ ZEND_API ZEND_COLD const char *zend_get_object_type(const zend_class_entry *ce)
 
 ZEND_API bool zend_is_iterable(zval *iterable) /* {{{ */
 {
-	switch (Z_TYPE_P(iterable)) {
-		case IS_ARRAY:
-			return 1;
-		case IS_OBJECT:
-			return zend_class_implements_interface(Z_OBJCE_P(iterable), zend_ce_traversable);
-		default:
-			return 0;
-	}
+	return EXPECTED(Z_TYPE_P(iterable) == IS_ARRAY)
+		|| EXPECTED(Z_TYPE_P(iterable) == IS_OBJECT);
 }
 /* }}} */
 

ext/reflection/php_reflection.c

@@ -5287,7 +5287,7 @@ ZEND_METHOD(ReflectionClass, isIterable)
 		RETURN_FALSE;
 	}
 
-	RETURN_BOOL(ce->get_iterator || instanceof_function(ce, zend_ce_traversable));
+	RETURN_TRUE;
 }
 /* }}} */
 

ext/reflection/tests/ReflectionClass_isIterateable_001.phpt

@@ -49,7 +49,7 @@ Is IteratorImpl iterable? bool(true)
 Is IteratorAggregateImpl iterable? bool(true)
 Is ExtendsIteratorImpl iterable? bool(true)
 Is ExtendsIteratorAggregateImpl iterable? bool(true)
-Is A iterable? bool(false)
+Is A iterable? bool(true)
 
 Test static invocation:
 

ext/reflection/tests/ReflectionClass_isIterateable_basic.phpt

@@ -14,14 +14,14 @@ class IteratorClass implements Iterator {
     function rewind(): void {}
 }
 class DerivedClass extends IteratorClass {}
-class NonIterator {}
+class RegularClass {}
 
 function dump_iterateable($class) {
     $reflection = new ReflectionClass($class);
     var_dump($reflection->isIterateable());
 }
 
-$classes = array("ArrayObject", "IteratorClass", "DerivedClass", "NonIterator");
+$classes = array("ArrayObject", "IteratorClass", "DerivedClass", "RegularClass");
 foreach ($classes as $class) {
     echo "Is $class iterateable? ";
     dump_iterateable($class);
@@ -31,4 +31,4 @@ foreach ($classes as $class) {
 Is ArrayObject iterateable? bool(true)
 Is IteratorClass iterateable? bool(true)
 Is DerivedClass iterateable? bool(true)
-Is NonIterator iterateable? bool(false)
+Is RegularClass iterateable? bool(true)

ext/reflection/tests/ReflectionClass_isIterateable_variation1.phpt

@@ -21,5 +21,5 @@ dump_iterateable($stdClass);
 
 ?>
 --EXPECT--
-bool(false)
-bool(false)
+bool(true)
+bool(true)

ext/standard/tests/general_functions/is_iterable.phpt

@@ -3,6 +3,16 @@ Test is_iterable() function
 --FILE--
 <?php
 
+function stdClassObjectFromJsonDecode() {
+    $exampleKeyValueStore = [
+        'key1' => 'value1',
+        'key2' => 'value2',
+        'key3' => 'value3'
+    ];
+
+    return json_decode(json_encode($exampleKeyValueStore));
+}
+
 function gen() {
     yield;
 }
@@ -13,6 +23,7 @@ var_dump(is_iterable(gen()));
 var_dump(is_iterable(1));
 var_dump(is_iterable(3.14));
 var_dump(is_iterable(new stdClass()));
+var_dump(is_iterable(stdClassObjectFromJsonDecode()));
 
 ?>
 --EXPECT--
@@ -21,4 +32,5 @@ bool(true)
 bool(true)
 bool(false)
 bool(false)
-bool(false)
+bool(true)
+bool(true)