TypeError: Cannot read properties of undefined (reading 'Symbol(ProxyTarget)')

[hpx7]

To repro:

class Foo {
  x() {
    const tmp = this.y;
    tmp(); // no error if we call this.y() directly
  }

  y() {}
}

const foo = new Foo();
const proxiedFoo = onChange(foo, () => {});
proxiedFoo.x();

Error is thrown on this line:

on-change/index.js

Line 164 in a40d3b9

const thisProxyTarget = thisArg[proxyTarget] || thisArg;

(thisArg is undefined)

[joeynenni]

Running into this same issue.