diff --git a/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_array.params.yaml b/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_array.params.yaml
new file mode 100644
index 0000000000..96e90d4f3a
--- /dev/null
+++ b/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_array.params.yaml
@@ -0,0 +1,97 @@
+# Copyright (c) 2024 Huawei Device Co., Ltd.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+---
+cases:
+    # 0. Regular extension functions
+    - decl: |-
+          class A {}
+          function A[].test() { return 1 }
+          function A[][].test() { return 2 }
+          function A[][][].test() { return 3 }
+      use: |-
+          let a: A[] = []
+          let b: A[][] = [[]]
+          let c: A[][][] = [[[]]]
+          assert a.test() == 1
+          assert b.test() == 2
+          assert c.test() == 3
+
+    # 1. Extension functions with different signatures
+    - decl: |-
+          class A {}
+          function A[].test(n: double) { return 1 }
+          function A[].test(n: string) { return 2 }
+          function A[].test(n: int) { return 3 }
+      use: |-
+          let a: A[] = [new A(), new A(), new A()]
+          assert a.test(1) == 3
+          assert a.test(14.1) == 1
+          assert a.test("test") == 2
+
+    # 2. Extension Function working with an array element
+    - decl: |-
+          class A {
+              value: int
+              constructor(n: int) { this.value = n }
+          }
+          function A[].test(i: int) { return this[i].value }
+      use: |-
+          let a: A[] = [new A(42), new A(81), new A(1), new A(890)] 
+          assert a.test(0) == 42
+          assert a.test(1) == 81
+          assert a.test(2) == 1
+          assert a.test(3) == 890
+  
+    # 3. Extension function working with built-in array member
+    - decl: |-
+          class A {}
+          function A[].test_len() { return this.length }
+      use: |-
+          let a: A[] = [new A(), new A(), new A(), new A()]
+          let b: A[] = []
+          assert a.test_len() == 4
+          assert b.test_len() == 0
+
+    # 4. Extension function with the same signatures for the class and the array.
+    - decl: |-
+          class A {}
+          function A.test() { return 1 }
+          function A[].test() { return 2 }
+      use: |-
+          let a = new A()
+          let b = [new A()]
+          assert a.test() == 1
+          assert b.test() == 2
+
+    # 5. Extension function for primitive array
+    - decl: |-
+          function int[].sum() {
+              let sum: int = 0;
+              for (let i of this) {
+                  sum += i
+              }
+              return sum;
+          }
+      use: |-
+          let a: int[] = [800000, 80000, 8000, 800, 80, 8]
+          assert a.sum() == 888888
+
+    # 6. Extension function is shadowed by built-in function
+    - decl: |-
+          function double[].toString() { 
+              return "ext-func"
+          }
+      use: |-
+          let a = [4.211, 0.00001, 1.2, 1.999]
+          assert a.toString() == "4.211,0.00001,1.2,1.999"
diff --git a/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_array.sts b/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_array.sts
new file mode 100644
index 0000000000..d64de96ee8
--- /dev/null
+++ b/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_array.sts
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2024 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+{%- for c in cases %}
+/*---
+desc: >-
+    The extension function mechanism allows using a special form of top-level functions
+    as extensions of class, interface or array.
+    These cases test array support.
+---*/
+
+{{c.decl}}
+
+function main() {
+    {{c.use|indent}}
+}
+{%- endfor %}
diff --git a/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_class.params.yaml b/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_class.params.yaml
new file mode 100644
index 0000000000..b7fb1d2f7b
--- /dev/null
+++ b/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_class.params.yaml
@@ -0,0 +1,96 @@
+# Copyright (c) 2024 Huawei Device Co., Ltd.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+---
+cases:
+    # 0. Regular extension functions
+    - decl: |-
+          class A {}
+          function A.test(n: int) { return n }
+      use: |-
+          let a = new A()
+          assert a.test(99) == 99
+
+    # 1. Extension functions with different signatures
+    - decl: |-
+          class A {}
+          function A.test(n: double) { return 1 }
+          function A.test(n: string) { return 2 }
+          function A.test(n: int) { return 3 }
+      use: |-
+          let a = new A()
+          assert a.test(1) == 3
+          assert a.test(14.1) == 1
+          assert a.test("test") == 2
+
+    # 2. Extension function working with class member
+    - decl: |-
+          class A { n1: int = 10 }
+          function A.test() { return this.n1 }
+      use: |-
+          let a = new A()
+          assert a.test() == 10
+
+    # 3. Extension function working with class member function
+    - decl: |-
+          class A { 
+              sum(n1: int, n2: int) {
+                return n1 + n2
+              }
+          }
+          function A.test(n1: int, n2: int) { 
+              return this.sum(n1, n2) 
+          }
+      use: |-
+          let a = new A()
+          assert a.test(99, 100) == 199
+
+    # 4. Extension function is shadowed by a class member function
+    - decl: |-
+          class A {
+              test(): int { return 1 }
+          }
+          function A.test(): int { return 2 }
+      use: |-
+          let a = new A()
+          assert a.test() == 1
+
+    # 5. Extension function and member function with different signatures
+    - decl: |-
+          class A {
+              test(n: long): int { return 1 }
+          }
+          function A.test(n: double): int { return 2 }
+      use: |-
+          let a = new A()
+          assert a.test(4140100.0) == 2
+          assert a.test(4140100) == 1
+
+    # 6. Extension function for built-in class
+    - decl: |-
+          function Long.test_add(n: long): long { 
+              return this as long  + n
+          }
+      use: |-
+          let a: Long = 1002000
+          assert a.test_add(444) == 1002444
+
+    # 7. Extension function is shadowed by built-in function
+    - decl: |-
+          function Object.toString() { 
+              return "ext-func"
+          }
+      use: |-
+          let a = new Object()
+          assert a.toString() == "[object Object]"
+
diff --git a/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_class.sts b/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_class.sts
new file mode 100644
index 0000000000..892343b90b
--- /dev/null
+++ b/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_class.sts
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2024 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+{%- for c in cases %}
+/*---
+desc: >-
+    The extension function mechanism allows using a special form of top-level functions
+    as extensions of class, interface or array.
+    These cases test class support.
+---*/
+
+{{c.decl}}
+
+function main() {
+    {{c.use|indent}}
+}
+{%- endfor %}
diff --git a/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_interface.params.yaml b/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_interface.params.yaml
new file mode 100644
index 0000000000..93cd6e8c3d
--- /dev/null
+++ b/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_interface.params.yaml
@@ -0,0 +1,74 @@
+# Copyright (c) 2024 Huawei Device Co., Ltd.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+---
+cases:
+    # 0. Regular extension functions
+    - decl: |-
+          interface I {}
+          class A implements I {}
+          function I.test(n: int) { return n }
+      use: |-
+          let a = new A()
+          assert a.test(99) == 99
+
+    # 1. Extension functions with different signatures
+    - decl: |-
+          interface I {}
+          class A implements I {}
+          function I.test(n: double) { return 1 }
+          function I.test(n: string) { return 2 }
+          function I.test(n: int) { return 3 }
+      use: |-
+          let a = new A()
+          assert a.test(1) == 3
+          assert a.test(14.1) == 1
+          assert a.test("test") == 2
+
+    # 2. Extension function working with interface member function
+    - decl: |-
+          interface I { 
+              sum(n1: int, n2: int) {
+                return n1 + n2
+              }
+          }
+          class A implements I {}
+          function I.test(n1: int, n2: int) { 
+              return this.sum(n1, n2) 
+          }
+      use: |-
+          let a = new A()
+          assert a.test(99, 100) == 199
+
+    # 3. Extension function is shadowed by a interface member function
+    - decl: |-
+          interface I {
+              test(): int { return 1 }
+          }
+          class A implements I {}
+          function I.test(): int { return 2 }
+      use: |-
+          let a = new A()
+          assert a.test() == 1
+
+    # 4. Extension function and member function with different signatures
+    - decl: |-
+          interface I {
+              test(n: long): int { return 1 }
+          }
+          class A implements I {}
+          function I.test(n: double): int { return 2 }
+      use: |-
+          let a = new A()
+          assert a.test(4140100.0) == 2
+          assert a.test(4140100) == 1
diff --git a/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_interface.sts b/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_interface.sts
new file mode 100644
index 0000000000..6eb05d179c
--- /dev/null
+++ b/static_core/plugins/ets/tests/ets-templates/17.experimental_features/11.extension_functions/extension_functions_interface.sts
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2024 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+{%- for c in cases %}
+/*---
+desc: >-
+    The extension function mechanism allows using a special form of top-level functions
+    as extensions of class, interface or array.
+    These cases test interface support.
+---*/
+
+{{c.decl}}
+
+function main() {
+    {{c.use|indent}}
+}
+{%- endfor %}