next.js: `swcMinify: true` does not produce an usable build with v12.1.5

@VeronikaSergiyenko I think it will be fixed by https://github.com/vercel/next.js/pull/36535

React now uses google closure compiler as their minifier, and it triggered a bug of swc minifier. So I disabled the problematic pass for now and I’m working on a full fix for alias analyzer

@seanparmelee

It will be fixed by https://github.com/vercel/next.js/pull/36351

(I used my own script to replace next-swc binary)

@kdy1 I can reproduce this error using a dependency as example:

/** @type {import('next').NextConfig} */
const nextConfig = {
  swcMinify: true,
};

module.exports = nextConfig;

{
  "name": "swc-test",
  "version": "0.1.0",
  "private": true,
  "scripts": {
    "dev": "next dev",
    "build": "next build",
    "start": "next start",
    "lint": "next lint"
  },
  "dependencies": {
    "@codemirror/text": "^0.19.6",
    "next": "12.1.6",
    "react": "18.2.0",
    "react-dom": "18.2.0"
  },
  "devDependencies": {
    "@types/node": "18.0.0",
    "@types/react": "18.0.14",
    "@types/react-dom": "18.0.5",
    "eslint": "8.18.0",
    "eslint-config-next": "12.1.6",
    "typescript": "4.7.4"
  }
}

import type { NextPage } from "next";
import { Text } from "@codemirror/text";

const Home: NextPage = () => {
  const length = Text.of(["Hello World"]).length;

  return <p>{length}</p>;
};

export default Home;

The variable value should always return 11, but if you set the swcMinify to true it returns -1. As far I could understand, this option is generating a different output of the following piece of code.

// Wrong
swcMinify: true,

// @codemirror/text
constructor(a, b=function(a) {
  for (let b of a)
    b.length;
  return -1
} 

// Correct
swcMinify: false,

// @codemirror/text
constructor(a, b=function(a) {
  let e = -1
  for (let b of a)
    e += b.length + 1;
  return e
}

Hope it helps

Edit: it has been fixed on Canary

We have been running into this issue in one of our apps as well (even on the latest canary). In our case, the following error is thrown:

TypeError: j is not a function
    at r.exports (util.js:1:46666)
    at Object.112 (util.js:1:46666)
    at __nccwpck_require__ (util.js:1:46666)
    at Object.749 (util.js:1:46666)
    at __nccwpck_require__ (util.js:1:46666)
    at Object.715 (util.js:1:46666)
    at __nccwpck_require__ (util.js:1:46666)
    at Object.3 (util.js:1:46666)
    at __nccwpck_require__ (util.js:1:46666)
    at Object.650 (util.js:1:46666)

After some process of elimination, the culprit turned out to be some code that was using

import { isString } from 'util';

And removing that code makes the error goes away.

I pushed up a simple reproduction here in hopes it helps get to the root cause of the issue (this form of it anyway): https://github.com/seanparmelee/nextjs-36127-reproduction

• Pull it down
• Run yarn build && yarn start
• Navigate to http://localhost:3000