@babel/plugin-transform-classses(createSuper)@7.9.x may have performance issue

Classes with super class are very slow to new, in comparison to what babel@7.8.8 does. The difference can be found at here.

function test(Vec3) {
    const t1 = Date.now();
    (() => {
        for (let i = 0; i < 1000000; ++i) {
            const x = Math.random();
            new Vec3(x, x, x); // Key line
        }
    })();
    const t2 = Date.now();
    console.log(`Past: ${t2 - t1}ms`);
}

test(require('./out/7.8.8/vec3.js').Vec3); // 18ms
test(require('./out/7.9.x/vec3.js').Vec3); // Oops, 2451ms!!

I have upload the test code to this repository. You can try it just by node ./run-perf.js.

[nicolo-ribaudo]

I’d be ok with a assumeNoExtendNative option to the classes plugin.

[nicolo-ribaudo]

It’s because with new you can’t specify the third parameter of Reflect.construct (new.target).