Returning a newly created derived object from an interface function is not allowed

Question

Returning a newly created derived object from an interface function is not allowed

Having trouble compiling my Typescript code.

Error Message: error TS2416: Property 'deepcopy' in type 'Vector2' is not assignable to the same property in base type 'Vector'.

I'm new to Typescript and encountered this issue shortly after starting. It seems simple, but I can't find a solution that works.

interface Vector {
    deepcopy() : this;
}

export class Vector2 implements Vector {
    constructor() {
    }

    deepcopy() {
        return new Vector2();
    }
}

Any hints or suggestions would be greatly appreciated.

typescript npm

Answer 1

Answer №1

interface Vector {
    clone() : Vector;
}

export class Vector2 implements Vector {
    constructor() {
    }

    clone() {
        return new Vector2();
    }
}

The issue here is that this is being used incorrectly as a type, causing Vector2 to not be compatible. By correcting it to Vector, you can create an instance that adheres to the Vector interface.

Answer 2

interface Vector {
    clone() : Vector;
}

export class Vector2 implements Vector {
    constructor() {
    }

    clone() {
        return new Vector2();
    }
}

The issue here is that this is being used incorrectly as a type, causing Vector2 to not be compatible. By correcting it to Vector, you can create an instance that adheres to the Vector interface.

Answer 3

Answer №2

Not sure if this approach will suit your specific situation, but consider utilizing an abstract class as an alternative:

export abstract class Vector {
  duplicate(): this {
    return { ...this };
  }
}
export class Vector2 extends Vector {
  constructor() {
    super();
  }
  /* add custom copy logic if needed
  duplicate(): this {
     ...
  }
  */
}

The following code will have the correct type annotations:

const x = new Vector2(); // inferred type: Vector2
const y = x.duplicate();  // inferred type: Vector2

Answer 4

Not sure if this approach will suit your specific situation, but consider utilizing an abstract class as an alternative:

export abstract class Vector {
  duplicate(): this {
    return { ...this };
  }
}
export class Vector2 extends Vector {
  constructor() {
    super();
  }
  /* add custom copy logic if needed
  duplicate(): this {
     ...
  }
  */
}

The following code will have the correct type annotations:

const x = new Vector2(); // inferred type: Vector2
const y = x.duplicate();  // inferred type: Vector2

Returning a newly created derived object from an interface function is not allowed

Answer №1

Answer №2

Similar questions

Efficiently Combining Objects with Rxjs

What is the process for verifying the installation of socket.io on my system?

Is it necessary to rebuild after every change in a react project?

Error: Update required to lodash version 3.0.0 to proceed with the build process

Deliver a numerical input to the component on an equivalent hierarchical tier

What is the process for obtaining a flattened tuple type from a tuple comprised of nested tuples?

What is the process for modifying input text and saving it for future use?

Creating Mongoose models in TypeScript with multiple connections

The header content contains an invalid character, specifically in the value of the header key "x-cypress-file-path" within

What is the reason for the regeneration of the 2D array?

Running ioBroker on a Windows 10 operating system

What is the Best Method for Dividing an Array in Typescript?

Can the getState() method be utilized within a reducer function?

What is the reason behind continuously receiving the error message stating "Not all code paths return a value here"?

Should one bother utilizing Promise.all within the context of a TypeORM transaction?

What is the process of mapping an object from a JSON file to a different object?

How can I enable dragging functionality for components (not elements) in angular?

What could be causing the type errors I am encountering while trying to resolve this Promise within a generic function?

Utilize the npm command following the execution of any other command

Executing a personalized npm command within Powershell on a Visual Studio Team Services hosted build agent