this before super() is a runtime error, not a static one.

[nicolo-ribaudo]

Q	A
Fixed Issues?	#6370
Patch: Bug Fix?	Yes
Major: Breaking Change?
Minor: New Feature?
Tests Added + Pass?	Yes
Documentation PR
Any Dependency Changes?

This errors were all thrown at compile-time, but they should be runtime errors:

class A extends B {
  constructor() {
    // Missing super
  }
}

class A extends B {
  constructor() {
    super.foo; // super.* before super()
    super();
  }
}

class A extends B {
  constructor() {
    this.foo; // this before super
    super();
  }
}

I have mixed feelings about 14f35c8: it makes the output faster and smaller, but it generates an inconsistent error message (this.foo; super() throws something like "Can't read property foo of undefined" instead of "this is not initialized")

[babel-bot]

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/6106/

[nicolo-ribaudo]

Rebased

[existentialism]

Super small nit: extraneous ass :)

[nicolo-ribaudo]

Lol I meant "add" 🤣
I will correct it later and then merge the pr.

[existentialism]

@nicolo-ribaudo lol sounds good

[xtuc]

I would prefer to be more explicit in the test here, like: typeof self === 'undefined'. It's faster.

[nicolo-ribaudo]

Which is faster? typeof self === "undefined" or self === void 0?

[nicolo-ribaudo]

I set up a not too much significative jsperf (https://jsperf.com/x-vs-typeof-vs-void-0/1) and they are almost the same. I'll stick with the second one since it is shorter.

[xtuc]

Great, thanks!

[xtuc]

👍