Open the dev tools, and in the console type:

and press enter.

The code being loaded on this page is:

class Foo {
    get value() {
        return 3;
    }
}

class Bar extends Foo {
    constructor() {
        super();
        this.valueId = 1;
    }
}

window.bar = new Bar();

In Chrome 68 autocomplete is actively selecting valueId and when you press enter it accepts that autocomplete:

This is a poor experience. If you have typed something that exactly matches something in the autocomplete dropdown, that item should be prioritized.

Also, if you do type bar.valueId you have to press enter twice to get it to execute.