How to dynamic import a local typescript file - node.js

Question

I have 2 files in the same folder. I want to dynamically import MyInterfaces.ts into index.ts.
// MyInterfaces.ts
export interface MyInterface1 {
id: number;
name: string;
}
// index.ts
async function importMyInterfaces() {
const myInterfaces = await import("./MyInterfaces");
const data1: myInterfaces.MyInterface1 = {
id: 1,
name: "John Doe",
};
}
I cannot figure how to achieve this without errors TS2503: Cannot find namespace 'myInterfaces'. I tried wrapping MyInterfaces.ts in a namespace but that didnt work either:
// MyInterfaces.ts
export namespace MyInterfaces {
export interface MyInterface1 {
id: number;
name: string;
}
}
// index.ts
async function importMyInterfaces() {
const {MyInterfaces} = await import("./MyInterfaces");
const data1: MyInterfaces.MyInterface1 = {
id: 1,
name: "John Doe",
};
}
TS2503: Cannot find namespace 'MyInterfaces'.
My tsconfig is set as follows with node 18:
{
"compilerOptions": {
"module": "commonjs",
"noImplicitReturns": true,
"noUnusedLocals": true,
"outDir": "lib",
"sourceMap": true,
"strict": true,
"target": "es2017"
},
"compileOnSave": true,
"include": [
"src"
]
}

Answer 1

If MyInterface1 was a default export, then you could asynchronously import and find the typeof within the importMyInterfaces() call.
MyInterfaces.ts
export default interface MyInterface1 {
id: number;
name: string;
}
index.ts
async function importMyInterfaces() {
const MyInterface1 = await import("./MyInterfaces");
const data1: typeof MyInterface1 = {
id: 1,
name: "John Doe"
};
console.log("data1", data1);
}
If you don't need to import asynchronously, then you can simply import at the top of index.ts.
MyInterfaces.ts
export interface MyInterface1 {
id: number;
name: string;
}
index.ts
import { MyInterface1 } from './MyInterfaces';
async function importMyInterfaces() {
const data1: MyInterface1 = {
id: 1,
name: "John Doe",
};
}