Editor_class_import.ts

//move.ts
import Test from "./test";
 private _test:Test;

    public onStart(): void {
        console.log(this._test._testNumber);
        this._test.showLog();
    }
//

//test.ts
export default class Test extends Node {
    public _testNumber:number;
    public onInitialize(): void {
        this._testNumber=3;
        // ...
    }
    
    public showLog:void(){
      console.log("showing log");
    }
}