Registry / testing / babel-plugin-unassert

babel-plugin-unassert

library3.2.0jsnpmunverified

Babel plugin that removes assertion calls (assert, console.assert, power-assert) from production builds. Current stable version is 3.2.0, compatible with Babel 7. Release cadence is low, with major versions tied to Babel major versions. Key differentiator: allows full use of assertions during development without runtime overhead in production, with support for ES modules and power-assert integration. Alternative to manual conditional wrapping or dead-code elimination.

testing devops

npm install babel-plugin-unassert

github ↗package ↗

INSTALL

IMPORT

SIG · BABEL-PLUGIN-UNASS

babel-plugin-unassert

testingjavascriptv3.2.0

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default export

✓ import unassert from 'babel-plugin-unassert'; module.exports = { plugins: ['babel-plugin-unassert'] };

✗ import { default } from 'babel-plugin-unassert'; const plugin = require('babel-plugin-unassert').default;

Plugin is a CommonJS module; use string name in Babel config or require() directly. No named exports.

require()

✓ const unassert = require('babel-plugin-unassert');

✗ const { unassert } = require('babel-plugin-unassert'); const unassert = require('babel-plugin-unassert').unassert;

Only default export exists; destructuring or .unassert will be undefined.

ESM import (if bundler allows)

✓ import unassert from 'babel-plugin-unassert';

✗ import { unassert } from 'babel-plugin-unassert'; import * as unassert from 'babel-plugin-unassert';

Package does not have a 'module' field; default import works if bundler resolves to CJS. Named import does not exist.

Demonstrates using babel-plugin-unassert via Babel config to remove assertions in production. Shows conditional plugin addition based on NODE_ENV.

// babel.config.js module.exports = function (api) { const presets = ['@babel/env']; const plugins = []; if (process.env.NODE_ENV === 'production') { plugins.push('babel-plugin-unassert'); } return { presets, plugins }; }; // src/math.js const assert = require('assert'); function add(a, b) { console.assert(typeof a === 'number'); assert(!isNaN(a)); return a + b; } // After build: // function add(a, b) { // return a + b; // }

Debug

Known issues

breakingBabel 7 is incompatible with Babel 6; babel-plugin-unassert v3 requires Babel 7.

fix

Use babel-plugin-unassert@2 for Babel 6, @1 for Babel <=5.

affects: >=3.0.0

breakingBabel 6 is incompatible with Babel 5; babel-plugin-unassert v2 requires Babel 6.

fix

Use babel-plugin-unassert@1 for Babel 5 or lower.

affects: >=2.0.0 <3.0.0

deprecatedbabel-plugin-unassert v1 is deprecated; use v2 or v3 with appropriate Babel version.

fix

Upgrade to v2 (Babel 6) or v3 (Babel 7) as per your Babel version.

affects: 1.x

gotchaPlugin removes only calls to assert, console.assert, and power-assert modules. Custom assert functions are not removed.

fix

Ensure your assertions use standard assert module or power-assert. Alternatively, ensure custom functions have no side effects.

affects: all

gotchaUsing require('babel-plugin-unassert') in Node returns the plugin function, not an object with a default property. Importing with ES named import fails.

fix

Use require('babel-plugin-unassert') or import default. Never destructure as { unassert }.

affects: all

Errors

Common errors & fixes

Error: Cannot find module 'babel-plugin-unassert'

Package not installed or incorrectly required.

fix

Run 'npm install --save-dev babel-plugin-unassert' and ensure it's in node_modules.

Error: [BABEL] unknown: Plugin babel-plugin-unassert is not a valid plugin (Error: Cannot find module 'babel-plugin-unassert')

String name in Babel config but plugin not installed.

fix

Install the plugin and ensure node_modules path is correct. Check for typos.

TypeError: babelPluginUnassert is not a function

Trying to use the default export incorrectly, e.g., destructuring.

fix

Use const plugin = require('babel-plugin-unassert'); not const { unassert } = require('babel-plugin-unassert');

Assertions not removed in production build

Plugin not added to Babel plugins list, or NODE_ENV not set correctly.

fix

Add 'babel-plugin-unassert' to plugins array when NODE_ENV === 'production'. Verify Babel config applies during build.

Upgrade

Version history

3.2.0latest on npm

Audit

Dependencies

@babel/coreoptionalpeer dependency for Babel plugin

Agent activity

19 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/unassert-js/babel-plugin-unassert ↗

packagehttps://www.npmjs.com/package/babel-plugin-unassert ↗