{"id":19420,"library":"corejs-upgrade-webpack-plugin","title":"CoreJS Upgrade Webpack Plugin","description":"A webpack plugin that transforms core-js v2 require/module paths to core-js v3 counterparts during bundling. Current stable version is 4.0.1 with maintenance-level releases. It resolves mismatched core-js versions by mapping old path patterns to new ones, preventing bundle bloat and runtime errors from library dependencies. Supports custom resolve directories via resolveFrom option. Released intermittently; uses core-js's path mapping to ensure the latest core-js is used everywhere. Differentiator: automates migration in existing webpack setups without manual code changes.","status":"maintenance","version":"4.0.1","language":"javascript","source_language":"en","source_url":"https://github.com/ndelangen/corejs-upgrade-webpack-plugin","tags":["javascript","core-js","path","resolve","transform","webpack"],"install":[{"cmd":"npm install corejs-upgrade-webpack-plugin","lang":"bash","label":"npm"},{"cmd":"yarn add corejs-upgrade-webpack-plugin","lang":"bash","label":"yarn"},{"cmd":"pnpm add corejs-upgrade-webpack-plugin","lang":"bash","label":"pnpm"}],"dependencies":[{"reason":"The plugin resolves core-js v2 paths against core-js v3 structure; core-js must be installed.","package":"core-js","optional":false},{"reason":"Webpack plugin; requires webpack as a peer dependency.","package":"webpack","optional":false}],"imports":[{"note":"ESM-only; default import. CommonJS require will fail.","wrong":"const CoreJSUpgradeWebpackPlugin = require('corejs-upgrade-webpack-plugin')","symbol":"CoreJSUpgradeWebpackPlugin","correct":"import CoreJSUpgradeWebpackPlugin from 'corejs-upgrade-webpack-plugin'"},{"note":"For CommonJS, use named destructuring. Default export is not available.","wrong":"const CoreJSUpgradeWebpackPlugin = require('corejs-upgrade-webpack-plugin').default","symbol":"CoreJSUpgradeWebpackPlugin","correct":"const { CoreJSUpgradeWebpackPlugin } = require('corejs-upgrade-webpack-plugin')"},{"note":"Use type import for TypeScript, not value import.","wrong":null,"symbol":"Options","correct":"import type { Options } from 'corejs-upgrade-webpack-plugin'"}],"quickstart":{"code":"// webpack.config.js\nimport CoreJSUpgradeWebpackPlugin from 'corejs-upgrade-webpack-plugin';\n\nexport default {\n  plugins: [\n    new CoreJSUpgradeWebpackPlugin({\n      resolveFrom: [process.cwd()],\n    }),\n  ],\n};","lang":"typescript","description":"Demonstrates ESM import and plugin instantiation with optional resolveFrom option for custom core-js resolution path."},"warnings":[{"fix":"Update resolveFrom to an array: new CoreJSUpgradeWebpackPlugin({ resolveFrom: [path] })","message":"Version 3.0.0 changed options structure; resolveFrom now expects an array.","severity":"breaking","affected_versions":"<3.0.0"},{"fix":"Consider using built-in webpack resolve.alias for core-js if applicable.","message":"The plugin is in maintenance mode; no new features planned.","severity":"deprecated","affected_versions":">=0.0.0"},{"fix":"Manually audit dependencies if multiple core-js versions remain.","message":"Plugin only transforms paths that match /core-js/; nested references may be missed.","severity":"gotcha","affected_versions":">=0.0.0"}],"env_vars":null,"last_verified":"2026-04-25T00:00:00.000Z","next_check":"2026-07-24T00:00:00.000Z","problems":[{"fix":"Use ESM import statement or use .mjs extension.","cause":"Attempting to require the plugin via CommonJS require.","error":"Cannot find module 'corejs-upgrade-webpack-plugin'"},{"fix":"Use import CoreJSUpgradeWebpackPlugin from 'corejs-upgrade-webpack-plugin' (ESM) or const { CoreJSUpgradeWebpackPlugin } = require('...') (CJS).","cause":"Wrong import style, e.g., using default import when plugin is exported as named.","error":"TypeError: CoreJSUpgradeWebpackPlugin is not a constructor"}],"ecosystem":"npm","meta_description":null,"install_score":null,"install_tag":null,"quickstart_score":null,"quickstart_tag":null}