babel: [Bug]: subclassing seems broken in older Chrome

💻

• Would you like to work on a fix?

How are you using Babel?

babel-loader (webpack)

Input code

(function (cb) {
	class Foo extends HTMLElement {
		connectedCallback() {
			this._baz = 'hello';
		}

		baz() {
			return this._baz;
		}
	}

	class Fooz extends Foo {
		connectedCallback() {
			super.connectedCallback();

			this._baz = this._baz + ' world';
		}
	}

	customElements.define('web-test-fooz', Fooz);
	document.body.appendChild(new Fooz());
	var fooz = document.getElementsByTagName('web-test-fooz')[0];

	cb(fooz.baz() === 'hello world');
})(callback);

Configuration file name

No response

Configuration

https://github.com/mrhenry/web-tests/blob/main/webpack-core-web.config.js#L166-L217

use: {
	loader: 'babel-loader',
	options: {
		comments: false,
		presets: [
			[
				'@babel/preset-env',
				{
					corejs: '^3.6.3',
					bugfixes: true,
					targets: {
						browsers: [
							"IE >= 8",
							"Opera >= 12",
							"Safari >= 5.1",
							"Chrome >= 15",
							"Edge >= 12",
							"Firefox >= 4"
						]
					},
					useBuiltIns: 'usage',
					exclude: [
						"web.dom-collections.iterator",
						"web.dom-collections.for-each"
					]
				}
			]
		]
	}
}

Current and expected behavior

Current :

Uncaught TypeError: Cannot call a class as a function

In function _classCallCheck

Expected subclasses to work.

Environment

Started occurring after upgrading @babel/core from 7.16.0 to 7.16.5

Possible solution

No response

Additional context

Test results page : https://mrhenry.github.io/web-tests/#53d613d8-773c-43d5-800b-a78aeeab8ef7

Results for chrome <=36 dropped below 1.0 indicating that the test is now failing. The only change between tests passing and tests failing is this commit : https://github.com/mrhenry/web-tests/commit/16599fd5bd5716d24c63d9dbed57ca63408796c9

(build outputs are included in git)

Test source code : https://github.com/mrhenry/web-tests/blob/main/specifications/whatwg/html/4.13.4.customElements.define.super/test.pure.js

Git blame for the affected build output :

https://github.com/mrhenry/web-tests/blame/main/specifications/whatwg/html/4.13.4.customElements.define.super/test.babel.js