Accessing Keys of a Typescript Interface as an Array of Strings

Introduction

Working with tabular data in Typescript requires the use of interfaces to define column structures. To efficiently manipulate these structures, it is often necessary to retrieve the property names of these interfaces as an array of strings.

Solution

Using Custom Transformers

Since Typescript version 2.4, custom transformers provide a mechanism to extract keys from interfaces. Consider the following interface:

interface IMyTable {
  id: number;
  title: string;
  createdAt: Date;
  isDeleted: boolean;
}

To obtain the property names as an array:

import { keys } from 'ts-transformer-keys';

const IMyTable = keys();

console.log(IMyTable); // ["id", "title", "createdAt", "isDeleted"]

Limitations of Custom Transformers

While custom transformers offer a convenient solution, they require the use of the Typescript transformation API rather than the ts command. This limitation can hinder their usability.

Alternatives

In scenarios where custom transformers are not feasible, alternative options include:

• Using reflection techniques (not recommended for performance reasons)
• Explicitly specifying the array of property names (prone to human error and maintenance overhead)