Fixes #392. More tests for Static extension methods syntax
diff --git a/LanguageFeatures/Extension-methods/syntax_type_t01.dart b/LanguageFeatures/Extension-methods/syntax_type_t01.dart
index 19a64c2..68340a3 100644
--- a/LanguageFeatures/Extension-methods/syntax_type_t01.dart
+++ b/LanguageFeatures/Extension-methods/syntax_type_t01.dart
@@ -17,7 +17,7 @@
* default (NNBD), this ? syntax is removed and subsumed by nullable types like
* int? being allowed in the <type> position.
*
- * @description Check that The type can be any valid Dart type, including a
+ * @description Check that the type can be any valid Dart type, including a
* single type variable
* @author sgrekhov@unipro.ru
*/
diff --git a/LanguageFeatures/Extension-methods/syntax_type_t02.dart b/LanguageFeatures/Extension-methods/syntax_type_t02.dart
index a1b5673..533a3f2 100644
--- a/LanguageFeatures/Extension-methods/syntax_type_t02.dart
+++ b/LanguageFeatures/Extension-methods/syntax_type_t02.dart
@@ -17,7 +17,7 @@
* default (NNBD), this ? syntax is removed and subsumed by nullable types like
* int? being allowed in the <type> position.
*
- * @description Check that The type can be any valid Dart type, including a
+ * @description Check that the type can be any valid Dart type, including a
* single type variable. Test nullable types
* @author sgrekhov@unipro.ru
*/
diff --git a/LanguageFeatures/Extension-methods/syntax_type_t03.dart b/LanguageFeatures/Extension-methods/syntax_type_t03.dart
new file mode 100644
index 0000000..8dc415f
--- /dev/null
+++ b/LanguageFeatures/Extension-methods/syntax_type_t03.dart
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
+ * for details. All rights reserved. Use of this source code is governed by a
+ * BSD-style license that can be found in the LICENSE file.
+ */
+/**
+ * @assertion an extension declaration is a top-level declaration with a grammar
+ * similar to:
+ * <extension> ::=
+ * `extension' <identifier>? <typeParameters>? `on' <type> `?'? `{'
+ * memberDeclaration*
+ * `}'
+ * ...
+ * The type can be any valid Dart type, including a single type variable. It can
+ * refer to the type parameters of the extension. It can be followed by ? which
+ * means that it allows null values. When Dart gets non-nullable types by
+ * default (NNBD), this ? syntax is removed and subsumed by nullable types like
+ * int? being allowed in the <type> position.
+ *
+ * @description Check that the type can be any valid Dart type, including a
+ * single type variable. Test built-in types
+ * @author sgrekhov@unipro.ru
+ */
+// SharedOptions=--enable-experiment=extension-methods
+
+extension MyInt on int {}
+
+extension MyNum on num {}
+
+extension MyDouble on double {}
+
+extension MyNull on Null {}
+
+extension MyString on String {}
+
+extension MyString on Void {}
+
+extension MyDynamic on dynamic {}
+
+extension MyBool on bool {}
+
+extension MyObject on Object {}
+
+extension MyFunction on Function {}
+
+main() {
+}
diff --git a/LanguageFeatures/Extension-methods/syntax_type_t04.dart b/LanguageFeatures/Extension-methods/syntax_type_t04.dart
new file mode 100644
index 0000000..da74641
--- /dev/null
+++ b/LanguageFeatures/Extension-methods/syntax_type_t04.dart
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
+ * for details. All rights reserved. Use of this source code is governed by a
+ * BSD-style license that can be found in the LICENSE file.
+ */
+/**
+ * @assertion an extension declaration is a top-level declaration with a grammar
+ * similar to:
+ * <extension> ::=
+ * `extension' <identifier>? <typeParameters>? `on' <type> `?'? `{'
+ * memberDeclaration*
+ * `}'
+ * ...
+ * The type can be any valid Dart type, including a single type variable. It can
+ * refer to the type parameters of the extension. It can be followed by ? which
+ * means that it allows null values. When Dart gets non-nullable types by
+ * default (NNBD), this ? syntax is removed and subsumed by nullable types like
+ * int? being allowed in the <type> position.
+ *
+ * @description Check that the type can be any valid Dart type, including a
+ * single type variable. Test nullable built-in types
+ * @author sgrekhov@unipro.ru
+ */
+// SharedOptions=--enable-experiment=extension-methods
+
+extension MyInt on int? {}
+
+extension MyNum on num? {}
+
+extension MyDouble on double? {}
+
+extension MyString on String? {}
+
+extension MyBool on bool? {}
+
+extension MyObject on Object? {}
+
+extension MyFunction on Function? {}
+
+main() {
+}
