Build breaks with browserslist configuration "supports es6-module"

[01231]

🐛 bug report

The build crashes. I found out when I remove this statement "browserslist": "supports es6-module" in the package.json the build works flawless.

🎛 Configuration (package.json)

{
  "name": "project",
  "version": "0.1.0",
  "description": "",
  "source": "src/index.html",
  "browserslist": "supports es6-module",
  "scripts": {
    "start": "parcel --open chrome",
    "build": "parcel build"
  },
  "repository": "",
  "author": "",
  "license": "MIT",
  "dependencies": {
    "eslint-config-airbnb": "^18.2.1",
    "eslint-config-prettier": "^8.3.0",
    "eslint-plugin-prettier": "^3.4.0"
  },
  "devDependencies": {
    "parcel": "^2.0.0-rc.0"
  }
}

🤔 Expected Behavior

In my opinion this should just work out of the box. I did run npx browserslist 'supports es6-module' to test if this is a valid query for browserslist and it did work.

😯 Current Behavior

This is the output when running yarn build.

$ parcel build
🚨 Build failed.

@parcel/transformer-js: Invalid Version: TP.0.0

  TypeError: Invalid Version: TP.0.0
  at new SemVer
  (.../project/node_modules/semver/semver.js:323:11)
  at compare
  (.../project/node_modules/semver/semver.js:614:39)
  at Function.gt
  (.../project/node_modules/semver/semver.js:643:10)
  at Object.transform
  (.../project/node_modules/@parcel/transformer-js/lib/JSTransformer.js:312:58)
  at processTicksAndRejections
  (internal/process/task_queues.js:95:5)
  at async Transformation.runTransformer
  (.../project/node_modules/@parcel/core/lib/Transformation.js:604:5)
  at async Transformation.runPipeline
  (.../project/node_modules/@parcel/core/lib/Transformation.js:357:36)
  at async Transformation.runPipelines
  (.../project/node_modules/@parcel/core/lib/Transformation.js:241:40)
  at async Transformation.run
  (.../project/node_modules/@parcel/core/lib/Transformation.js:167:19)
  at async Child.handleRequest
  (.../project/node_modules/@parcel/workers/lib/child.js:217:9)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

💁 Possible Solution

🔦 Context

💻 Code Sample

🌍 Your Environment

Software	Version(s)
Parcel	^2.0.0-rc.0
Node	v14.17.0.
npm/Yarn	1.22.11
Operating System	macOS Big Sur 11.4

[devongovett]

Seems like potentially an issue with browserslist. They should be returning a version number. I'm not sure what TP is...

[mischnic]

parcel/packages/transformers/js/src/JSTransformer.js

Lines 311 to 329 in 95f5648

	let [name, version] = browser.split(' ');
	if (BROWSER_MAPPING.hasOwnProperty(name)) {
	name = BROWSER_MAPPING[name];
	if (!name) {
	continue;
	}
	}
	let [major, minor = '0', patch = '0'] = version
	.split('-')[0]
	.split('.');
	let semverVersion = `${major}.${minor}.${patch}`;
	if (
	targets[name] == null ||
	semver.gt(targets[name], semverVersion)
	) {
	targets[name] = semverVersion;
	}

browser is "safari TP", then semverVersion is TP.0.0 which is of course an invalid version number

[cekvenich2]

Watching.

[folknor]

In fact the bug is with any valid supports foo keyword, as far as I can see - I tested 6 of them.
EDIT: Ah, I read the relevant code above now, please excuse my unnecessary comment.