@naturalcycles/js-lib/src/env.ts

Standard library for universal (browser + Node.js) javascript

/**
 * Use it to detect SSR/Node.js environment.
 *
 * Will return `true` in Node.js.
 * Will return `false` in the Browser.
 */
export function isServerSide(): boolean {
  return !isClientSide()
}

/**
 * Use it to detect Browser (not SSR/Node) environment.
 *
 * Will return `true` in the Browser.
 * Will return `false` in Node.js.
 */
export function isClientSide(): boolean {
  // oxlint-disable-next-line unicorn/prefer-global-this
  return typeof window !== 'undefined' && !!window?.document
}

/**
 * Almost the same as isServerSide()
 * (isServerSide should return true for Node),
 * but detects Node specifically (not Deno, not Bun, etc).
 */
export function isNode(): boolean {
  return typeof process !== 'undefined' && process?.release?.name === 'node'
}