isDevBuild()

import { isDevBuild } from '@dr.pogodin/react-utils';

function isDevBuild(): boolean;

Returns boolean — true if the development version of code is running, false otherwise.

Beware

It relies on Babel and Webpack configurations provided by react-utils library being used by the host code, along with provided mechanics for server creation and client-side app initialization. It won't work correctly with a different app setup.