@babel/plugin-transform-instanceof

NOTE: This plugin is included in @babel/preset-env

Example

In

  1. foo instanceof Bar;

Out

  1. function _instanceof(left, right) {
  2.   if (
  3.     right != null &&
  4.     typeof Symbol !== "undefined" &&
  5.     right[Symbol.hasInstance]
  6.   ) {
  7.     return right[Symbol.hasInstance](left);
  8.   } else {
  9.     return left instanceof right;
  10.   }
  11. }
  13. _instanceof(foo, Bar);

Installation

  1. npm install --save-dev @babel/plugin-transform-instanceof

Usage

With a configuration file (Recommended)

  1. {
  2.   "plugins": ["@babel/plugin-transform-instanceof"]
  3. }

Via CLI

  1. babel --plugins @babel/plugin-transform-instanceof script.js

Via Node API

  1. require("@babel/core").transformSync("code", {
  2.   plugins: ["@babel/plugin-transform-instanceof"],
  3. });

References