getEnumEntries function

Lists the members of an enum as [name, value] pairs, without the reverse mapping of numeric enums.

import { getEnumEntries } from 'utils';

Signature

export function getEnumEntries<E extends EnumObject>(enumObject: E): [key: keyof E & string, value: E[keyof E]][]

Parameters

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

Returns

The [name, value] pairs, in declaration order.

Example

enum Direction { Up, Down }
getEnumEntries(Direction); // [['Up', 0], ['Down', 1]]

Tests

Line coverage: 100 %.

• ✅ lists name and value pairs without the reverse mapping

Source

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

Uses

• EnumObject: Any TypeScript enum, or a const object used as one.

Used by

• getEnumKey: Finds the member name of an enum value, string enums included: a readable name for a log or a translation key.
• getEnumKeys: Lists the member names of an enum, without the reverse mapping of numeric enums.
• getEnumValues: Lists the values of an enum, without the names of the reverse mapping of numeric enums.
• parseEnumValue: Reads an enum member from a text, such as a query parameter: '1' gives the member of value 1.

Files it needs

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

• src/enum/enum-object.ts

Source code

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

/**
 * Lists the members of an enum as `[name, value]` pairs, 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 `[name, value]` pairs, in declaration order.
 * @example
 * enum Direction { Up, Down }
 * getEnumEntries(Direction); // [['Up', 0], ['Down', 1]]
 */
export function getEnumEntries<E extends EnumObject>(enumObject: E): [key: keyof E & string, value: E[keyof E]][] {
  const entries: [keyof E & string, E[keyof E]][] = [];
  for (const [key, value] of Object.entries(enumObject)) {
    if (String(Number(key)) !== key) {
      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion -- A value of `E`, read from `E`.
      entries.push([key, value as E[keyof E]]);
    }
  }
  return entries;
}

Test file

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

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

enum Status {
  Idle = 'idle',
  Running = 'running',
}

describe(getEnumEntries, () => {
  it('lists name and value pairs without the reverse mapping', () => {
    expect(getEnumEntries(Direction)).toStrictEqual([
      ['Up', 0],
      ['Down', 1],
    ]);
    expect(getEnumEntries(Status)).toStrictEqual([
      ['Idle', 'idle'],
      ['Running', 'running'],
    ]);
  });
});

Keywords: get, enum, entries, enums, function