Transform for static super.name is incorrect when prototype is mutated

[evanw]

Bug Report

🔎 Search Terms

class static field super prototype setPrototypeOf

🕗 Version & Regression Information

• The ability to use super inside static appears to have been added in 4.4. This bug existed when the feature was introduced, presumably in Change static fields emits #43114.

⏯ Playground Link

Playground link with relevant code

💻 Code

class A {
  static x = 1
}
class B extends A {
  static y = () => super.x
}
class C {
  static x = 2
}
console.log(B.y())
Object.setPrototypeOf(B, C)
console.log(B.y())

🙁 Actual behavior

When this code is transformed by TypeScript, it outputs 1 1.

🙂 Expected behavior

When this code is run natively, it outputs 1 2.

The code generated by TypeScript currently looks like this:

"use strict";
var _a, _b;
class A {
}
A.x = 1;
class B extends (_b = A) {
}
_a = B;
B.y = () => Reflect.get(_b, "x", _a);
class C {
}
C.x = 2;
console.log(B.y());
Object.setPrototypeOf(B, C);
console.log(B.y());

I expected something like this instead:

"use strict";
var _a;
class A {
}
A.x = 1;
class B extends A {
}
_a = B;
B.y = () => Reflect.get(Object.getPrototypeOf(_a), "x", _a);
class C {
}
C.x = 2;
console.log(B.y());
Object.setPrototypeOf(B, C);
console.log(B.y());