import { copyFile } from 'fs'; // Configure Angular `environment.ts` file path const sourcePath = './src/environments/mock-environment.ts'; const targetPath = './src/environments/environment.ts'; // destination.txt will be created or overwritten by default. copyFile(sourcePath, targetPath, (err) => { if (err) throw err; console.log(sourcePath + ' was copied to ' + targetPath); });