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

What is @babel/plugin-transform-nullish-coalescing-operator?

The @babel/plugin-transform-nullish-coalescing-operator package allows Babel to transform nullish coalescing operator (??) syntax into equivalent JavaScript code that can run in environments that do not support this operator. The nullish coalescing operator is a logical operator that returns its right-hand side operand when its left-hand side operand is null or undefined, and otherwise returns its left-hand side operand.

What are @babel/plugin-transform-nullish-coalescing-operator's main functionalities?

Transform nullish coalescing operator

This feature transforms the nullish coalescing operator (??) into equivalent JavaScript code. In this example, if 'foo' is null or undefined, 'bar' will be set to 'default value'. Otherwise, 'bar' will be set to the value of 'foo'.

const foo = null;\nconst bar = foo ?? 'default value';

Other packages similar to @babel/plugin-transform-nullish-coalescing-operator

@babel/plugin-proposal-optional-chaining

This package allows Babel to transform optional chaining (?.) syntax, which is somewhat related to the nullish coalescing operator in that it helps with dealing with null or undefined values. However, optional chaining is used to access properties of an object without having to explicitly check if each reference in the chain is null or undefined.

@babel/preset-env

While not a direct equivalent, @babel/preset-env includes support for transforming nullish coalescing operators among many other JavaScript features based on the target environment. It's a broader solution for compiling modern JavaScript down to a version compatible with older browsers or environments.

README

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

Remove nullish coalescing operator

See our website @babel/plugin-transform-nullish-coalescing-operator for more information.

Install

Using npm:

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

or using yarn:

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

Changelog

v7.25.9 (2024-10-22)

:bug: Bug Fix

• babel-parser, babel-template, babel-types
  • #16905 fix: Keep type annotations in syntacticPlaceholders mode (@liuxingbaoyu)
• babel-helper-compilation-targets, babel-preset-env
  • #16907 fix: support BROWSERSLIST{,_CONFIG} env (@JLHwung)
• Other
  • #16884 Analyze ClassAccessorProperty to prevent the no-undef rule (@victorenator)

:house: Internal

• babel-helper-transform-fixture-test-runner
  • #16914 remove test options flaky (@JLHwung)

:running_woman: Performance

• babel-parser, babel-types
  • #16918 perf: Make VISITOR_KEYS etc. faster to access (@liuxingbaoyu)