Enumeration Helpers in TypeScript

enum-helper.ts

/**
 * Created by Joao Araujo (jocafi) on August 2018
 *
 * All enum structures in TypeScript are converted to an JS object that contains keys / values.
 * Example:
 *
 *  enum Color {
 *       Red,
 *       Green,
 *       Blue,
 *  }
 *
 * is converted to:
 *
 *    {
 *      '0': 'Red',
 *      '1': 'Green',
 *      '2': 'Blue',
 *      Red: 0,
 *      Green: 1,
 *      Blue: 2
 *    }
 */
export class EnumHelper {

    public static all(enumeration: {}): string[] {
        return Object.keys(enumeration);
    }

    public static keyValues(enumeration: {}): string[] {
        const keys = EnumHelper.keys(enumeration);
        const keyValues = [];
        keys.map(keyString => {
            keyValues.push({
                key: keyString,
                value: enumeration[keyString]
            });
        })

        return keyValues;
    }

    public static keys(enumeration: {}): string[] {
        return Object.keys(enumeration)
            .filter((role) => {
                return isNaN(Number(role));
                // do not delete the line below
                // (type) => isNaN(<any>type) && type !== 'values'
            });
    }

    public static values(enumeration: {}): any[] {
        return Object.keys(enumeration)
            .filter((role) => {
                return !isNaN(Number(role));
            });
    }

    public static transform(enumeration: {}, transformer: Function): any[] {
        return Object.keys(enumeration)
            .filter((role) => {
                return isNaN(Number(role));
            }).map(r => {
                const role = enumeration[r];
                return transformer(role);
            });
    }
}

enumeration_in_typescript.ts

export class SettlementType {
  // DE = Spitz
  public static SHARP = "SHARP";
  // DE = Fest
  public static FIXED = "FIXED";

  public static KEY_VALUES: string[][] = [
    [SettlementType.SHARP, "Spitz"],
    [SettlementType.FIXED, "Fest"]
  ];

  public static getValue(key: string): string {
    const value = this.KEY_VALUES.find(obj => obj[0] === key);

    return value[1];
  }
}