Using ES Modules

hello/srv/world.js

@@ -1,7 +1,6 @@
-module.exports = class say {
-  hello(req) {
-    let {to} = req.data
-    if (to === 'me') to = require('os').userInfo().username
+import cds from '@sap/cds'
+export class say extends cds.ApplicationService {
+  hello (to = 'World') {
     return `Hello ${to}!`
   }
 }

hello/srv/world.ts

@@ -1,7 +1,6 @@
-import { Request } from "@sap/cds"
-
-module.exports = class say {
-    hello(req: Request) {
-        return `Hello ${req.data.to} from a TypeScript file!`
-    }
+import cds from '@sap/cds'
+export class say extends cds.ApplicationService {
+  hello (to : String = 'World') {
+    return `Hello ${to} from TypeScript!`
+  }
 }