1634037 - No error logged on ES module import reassignment

Status: RESOLVED INVALID

(DevTools :: Console, enhancement)

Description

[Bruno]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Firefox/68.0

Steps to reproduce:

/* module.js */
export let foo = false;

/* index.js */
import { foo } from "./module.js";

console.log(foo); // false
foo = true;
console.log(foo);

Actual results:

Execution stops right at the line foo = true;, the second log is never reached.
No error is thrown.

Expected results:

As imports are read-only views on exports, I would not expect the reassignment to work, thus the second log to be reached.
I would however expect an error to be thrown in the console, having some explanations.

Comment 1

[Nicolas Chevobbe [:nchevobbe]]

Hello Bruno,

I put up a simple test page : https://es-module-reassign.glitch.me/ , and I do see the following error (tested in Firefox 74, 75 and 77):

TypeError: "foo" is read-only

could you check if you see it on the test page ?
If not, maybe you have the "Error" filter disabled? Or a search in the console filter input? Or maybe nothing of that kind, and there's an issue we need to investigate further.

Comment 2

[Bruno]

I feel dumb right now :) Bug can be closed.
I have no idea why my error filter was off, I never put it off...
Anyway, works as intended, my bad!