@babel/plugin-transform-nullish-coalescing-operator

info

This plugin is included in @babel/preset-env, in ES2020

Example

In

JavaScript

var foo = object.foo ?? "default";

Out

JavaScript

var _object$foo;
var foo =
  (_object$foo = object.foo) !== null && _object$foo !== void 0
    ? _object$foo
    : "default";

note

We cannot use != null here because document.all == null and document.all has been deemed not “nullish”.

Installation

• npm
• Yarn
• pnpm

npm install --save-dev @babel/plugin-transform-nullish-coalescing-operator

yarn add --dev @babel/plugin-transform-nullish-coalescing-operator

pnpm add --save-dev @babel/plugin-transform-nullish-coalescing-operator

Usage

With a configuration file (Recommended)

babel.config.json

{
  "plugins": ["@babel/plugin-transform-nullish-coalescing-operator"]
}

Via CLI

Shell

babel --plugins @babel/plugin-transform-nullish-coalescing-operator script.js

Via Node API

JavaScript

require("@babel/core").transformSync("code", {
  plugins: ["@babel/plugin-transform-nullish-coalescing-operator"],
});

Options

loose

boolean, defaults to false.

When true, this transform will pretend document.all does not exist, and perform loose equality checks with null instead of strict equality checks against both null and undefined.

caution

Consider migrating to the top level noDocumentAll assumption.

babel.config.json

{
  "assumptions": {
    "noDocumentAll": true
  }
}

Example

In

JavaScript

var foo = object.foo ?? "default";

Out

JavaScript

var _object$foo;
var foo = (_object$foo = object.foo) != null ? _object$foo : "default";

tip

You can read more about configuring plugin options here

References

• Proposal: Nullish Coalescing