update build script and refactor code for ES module compatibility

package.json

@@ -5,7 +5,7 @@
   "main": "dist/index.js",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1",
-    "build": "tsc",
+    "build": "rm -rf dist/* && tsc",
     "start": "node dist/index.js",
     "dev": "ts-node src/index.ts",
     "lint": "eslint .",

src/index.ts

@@ -1,9 +1,9 @@
-import { greet } from './lib/greeter'
-import { Person } from './types'
+import { Person } from './types.js';
+import { greet } from './lib/greeter.js';
 
 const person: Person = {
-  firstName: 'Jane',
-  lastName: 'Doe',
-}
+  firstName: 'John',
+  lastName: 'Doe'
+};
 
-console.log(greet(`${person.firstName} ${person.lastName}`))
+console.log(greet(person));

src/lib/greeter.ts

@@ -1,3 +1,5 @@
-export function greet(name: string): string {
-  return `Hello, ${name}!`
+import { Person } from '../types.js';
+
+export function greet(person: Person): string {
+  return `Hello ${person.firstName} ${person.lastName}!`;
 }

tsconfig.json

@@ -25,10 +25,10 @@
     // "moduleDetection": "auto",                        /* Control what method is used to detect module-format JS files. */
 
     /* Modules */
-    "module": "commonjs" /* Specify what module code is generated. */,
+    "module": "NodeNext" /* Specify what module code is generated. */,
     "outDir": "./dist" /* Specify an output folder for all emitted files. */,
-    // "rootDir": "./",                                  /* Specify the root folder within your source files. */
-    // "moduleResolution": "node10",                     /* Specify how TypeScript looks up a file from a given module specifier. */
+    "rootDir": "./src", /* Specify the root folder within your source files. */
+    "moduleResolution": "NodeNext",                     /* Specify how TypeScript looks up a file from a given module specifier. */
     // "baseUrl": "./",                                  /* Specify the base directory to resolve non-relative module names. */
     // "paths": {},                                      /* Specify a set of entries that re-map imports to additional lookup locations. */
     // "rootDirs": [],                                   /* Allow multiple folders to be treated as one when resolving modules. */
@@ -108,5 +108,6 @@
     /* Completeness */
     // "skipDefaultLibCheck": true,                      /* Skip type checking .d.ts files that are included with TypeScript. */
     "skipLibCheck": true /* Skip type checking all .d.ts files. */
-  }
+  },
+  "include": ["src/**/*"]
 }