typescript inherit / extend multiple classes

multi-extends-class.ts

interface User extends BaseUser, BaseEntity {}

class User {
  public get fullName() : string {
    return `${this.firstName} ${this.lastName}`
  }
}
applyMixins(User, [BaseUser, BaseEntity])


function applyMixins(derivedCtor: any, baseCtors: any[]) {
  baseCtors.forEach((baseCtor) => {
    Object.getOwnPropertyNames(baseCtor.prototype).forEach((name) => {
      const propertyDescriptor = Object.getOwnPropertyDescriptor(baseCtor.prototype, name)
      if (!propertyDescriptor) throw new Error(`cannot find property descriptor of class ${baseCtor}`)
      Object.defineProperty(
        derivedCtor.prototype,
        name,
        propertyDescriptor
      )
    })
  })
}