added test cases for api gateway

Author: KevithMannage

API_Gateway/babel.config.cjs

@@ -0,0 +1,10 @@
+module.exports = {
+  presets: [
+    [
+      "@babel/preset-env",
+      {
+        targets: { node: "current" }, // for Node.js environment
+      },
+    ],
+  ],
+};

API_Gateway/jest.config.js

@@ -0,0 +1,4 @@
+export default {
+  testEnvironment: "node",
+  // transform is optional; babel-jest will handle .js files automatically
+};