getEnumKeys function

Lists the member names of an enum, without the reverse mapping of numeric enums.

import { getEnumKeys } from 'utils';

Signature

export function getEnumKeys<E extends EnumObject>(enumObject: E): (keyof E & string)[]

Parameters

Name	Description
E	The type of the enum object.
enumObject	The enum to read, such as Direction.

Returns

The member names, in declaration order.

Example

enum Direction { Up, Down }
getEnumKeys(Direction); // ['Up', 'Down']

Tests

Line coverage: 100 %.

• ✅ lists the member names without the reverse mapping

Source

src/enum/get-enum-keys.ts (on GitHub)

Uses

• EnumObject: Any TypeScript enum, or a const object used as one.
• getEnumEntries: Lists the members of an enum as [name, value] pairs, without the reverse mapping of numeric enums.

Files it needs

src/enum/get-enum-keys.ts imports, directly or not:

• src/enum/enum-object.ts
• src/enum/get-enum-entries.ts

Source code

import type { EnumObject } from './enum-object';
import { getEnumEntries } from './get-enum-entries';

/**
 * Lists the member names of an enum, without the reverse mapping of numeric enums.
 *
 * @template E - The type of the enum object.
 * @param enumObject - The enum to read, such as `Direction`.
 * @returns The member names, in declaration order.
 * @example
 * enum Direction { Up, Down }
 * getEnumKeys(Direction); // ['Up', 'Down']
 */
export function getEnumKeys<E extends EnumObject>(enumObject: E): (keyof E & string)[] {
  return getEnumEntries(enumObject).map(([key]) => key);
}

Test file

import { getEnumKeys } from './get-enum-keys';

enum Direction {
  Up = 0,
  Down = 1,
}

enum Status {
  Idle = 'idle',
}

describe(getEnumKeys, () => {
  it('lists the member names without the reverse mapping', () => {
    expect(getEnumKeys(Direction)).toStrictEqual(['Up', 'Down']);
    expect(getEnumKeys(Status)).toStrictEqual(['Idle']);
  });
});

Keywords: get, enum, keys, enums, function