Typescript Chain Constants with a Negative function

Question

I am working in Typescript 2.8.1 and want to group my constants into a common file, similar to an include file in other languages. While this is straight forward, I am trying to chain some methods to work with the values and cannot seem to get it to work.

EDIT: Need a default return for simplicity and have correcte my initial problem of not returning the object.

For instance, I have the numbers 1 to 10 as defined constants:

export enum CONSTANTS {
    ONE = 1, TWO, ... TEN
}

I want to be able to use these in code, such as CONSTANTS.FIVE for the number 5, but also be able to possibly do a CONSTANTS.NEGATIVE.FIVE to get -5.

I am trying to use chained methods, but it appears that I need to then define the original enumerations as individual methods that return a value.

export class CONSTANTS {
    private Value_:number;

    public constructor() {
        this.Value_ = 0;
    }
    public ONE() {
        this.Value_ = 1;
        return this;
    }
    public TWO() {
        this.Value_ = 2;
        return this;
    }
    public NEGATIVE() {
        this.Value_ = this.Value_ * -1;
        return this;
    }
    public GetValue() {
        return this.Value_;    // This is the function I want to default to at the end
}

value = new CONSTANTS().ONE().NEGATIVE();        // Trying for -1

Leaving off the GetValue(); returns the object.

Answer 1

As an alternative, and to simplify your code you could use the negative unary operator:

export enum CONSTANTS {
    ONE = 1, TWO = 2, ... TEN
}

//**//

console.log(-CONSTANTS.TWO)