"Const must be initialized" JavaScript error on every page in IE 11
Summary
On every page of GitLab.com, I'm seeing a Const must be initialized
error in the dev tools console in IE 11:
Steps to reproduce
Visit https://gitlab.com/nfriend in IE 11 and open the dev tools console (F12). (For those without access to a Windows machine, you can use BrowserStack).
What is the current bug behavior?
A JavaScript error (Const must be initialized
) is thrown in the main bundle (main.<hash>.chunk.js
), which prevents the page from continuing to render.
This behavior only happens in IE 11.
What is the expected correct behavior?
No error should be thrown and the page should render correctly.
Relevant logs and/or screenshots
Here's the version of IE I'm using:
I'm on Windows 10.
The error is occurring in main.21e6b1d9.chunk.js
on line 135, column 36359.
Output of checks
This bug happens on GitLab.com. (Both current and next.)
Possible fixes
I did a little investigating
for(const e in t)
I built a small jsFiddle to test this code and ran it in IE 11 (through BrowserStack): https://jsfiddle.net/NathanFriend/rz72k1ta/
var myObj = {
a: 1,
b: 2
}
for (const key in myObj) {
alert(key);
}
This code runs correctly in Chrome, but throws the same error message mentioned above in IE 11: