Parcel Incorrectly Detects Destructuring Assignment As Module Usage

[an0nusr]

🐛 bug report

When using Parcel 2.2.0 with a single HTML file with an inline script, Parcel incorrectly identifies a destructuring assignment as some sort of module, triggering the error: @parcel/transformer-js: Browser scripts cannot have imports or exports. when running parcel build.

Writing this will trigger the error in an inline script block:

let [prev, last] = getLastLine(currentBlock)

However, writing this does not:

let res = getLastLine(currentBlock)
let prev = res[0]
let last = res[1]

🎛 Configuration (.babelrc, package.json, cli command)

Package json:

{
  "name": "furryfont",
  "version": "1.0.0",
  "source": "index.html",
  "browserslist": "> 0.5%, last 2 versions, not dead",
  "author": "anonusr",
  "license": "AGPL-3.0-only",
  "scripts": {
    "start": "parcel",
    "build": "parcel build",
    "deploy": "echo 'furryfont.anonusr.org' > ./dist/CNAME && gh-pages -d dist"
  },
  "devDependencies": {
    "gh-pages": "^3.2.3",
    "parcel": "^2.2.0"
  }
}

🤔 Expected Behavior

The inline script, that does not use any modules, should build as expected.

😯 Current Behavior

Parcel incorrectly declares that I'm using a module when I attempt to build the package:

🚨 Build failed.

@parcel/transformer-js: Browser scripts cannot have imports or exports.

  /home/user/furryfont/index.html:81:1
    80 |
  > 81 |         <script>
  >    | ^
    82 |             function render_editor() {
    83 |                 window.quill = new Quill('#editor', {

  💡 Add the type="module" attribute to the <script> tag.
  📝 Learn more: https://parceljs.org/languages/javascript/#classic-scripts

error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

🔦 Context

This was frustrating as I needed to go through my last commit line by line to see what was causing the build system to fail. I knew I hadn't used an import, so the error caught me offguard.

💻 Code Sample

You can view my code here: https://github.com/an0nusr/furryfont/commits/main

The issue began when I introduced the destructuring assignment in commit 9df206bc65b559d8326f5263d66f3b4e1cbdac23.

It resolved when I rewrote the line in commit: 7e279a691c8faeeaac536debf3557b1ec838322c

🌍 Your Environment

Software	Version(s)
Parcel	2.2.0
Node	v12.22.7
npm/Yarn	yarn 1.22.5
Operating System	Ubuntu 18.04

[Shinyaigeek]

This bug seems to be caused by this line. when swc parses code, swc replaces let [prev, last] = getLines() with

const _helpers = require("@swc/helpers");
let [prev, last] = _helpers.slicedToArray(getLastLine());

[Shinyaigeek]

I sent PR to fix this #7599