diff --git a/.vscode/extensions.json b/.vscode/extensions.json
new file mode 100644
index 00000000..e2dcfca1
--- /dev/null
+++ b/.vscode/extensions.json
@@ -0,0 +1,5 @@
+{
+    "recommendations": [
+        "GitHub.copilot"
+    ]
+}
\ No newline at end of file
diff --git a/__test__/datasources/inherit.test.js b/__test__/datasources/inherit.test.js
new file mode 100644
index 00000000..a986e611
--- /dev/null
+++ b/__test__/datasources/inherit.test.js
@@ -0,0 +1,20 @@
+"use strict";
+exports.__esModule = true 
+var assert = require("assert");
+
+import ModelFactory  from '../../esm/domain/model-factory'
+
+describe("datasource inheritance", function () {
+  describe("polymorph", function () {
+    it("dataSource.saveSync()", async function () {
+    /**@type {import("../../src/domain/datasource").default} */
+      const dsMemory = require('../../src/domain/datasource-factory').getDataSource("test", {adapter:'DataSourceMemory'})
+        /**@type {import("../../src/domain/datasource").default} */
+      const dsMongo = require('../../src/domain/datasource-factory').getDataSource("test", {adapter:'DataSourceMongoDb'})
+      dsMemory.saveSync(1, {a:1})
+      dsMongo.saveSync(1, {b:2})
+      console.log(dsMemory.findSync(1))
+      assert.strictEqual(updated.a, "b");
+    });
+  });
+});
diff --git a/__test__/template.test.js b/__test__/template.test.js
new file mode 100644
index 00000000..b98ed4dd
--- /dev/null
+++ b/__test__/template.test.js
@@ -0,0 +1,13 @@
+"use strict";
+
+var assert = require("assert");
+
+
+describe("testName", function () {
+    it("this test will pass", function () {
+        assert.strictEqual(1,1);
+    });
+});
+
+
+
diff --git a/package.json b/package.json
index 38124c9e..6d93572a 100644
--- a/package.json
+++ b/package.json
@@ -32,6 +32,7 @@
     "ipfs": "^0.61.0",
     "jwks-rsa": "2.0.5",
     "mesh-link": "0.13.6",
+    "mocha-esm": "^1.1.1",
     "mongodb": "4.3.1",
     "multicast-dns": "7.2.4",
     "nanoid": "3.2.0",