1370417 - es module bug with file:///

Status: RESOLVED WONTFIX

(Core :: JavaScript Engine, defect, P3)

Description

[capocyril]

Attachment: subfolderbugrepro.zip

User Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:54.0) Gecko/20100101 Firefox/54.0
Build ID: 20170529025115

Steps to reproduce:


When using modules, with an html file, served directly from disk with file:///

import statement that use relative path with a sub-folder like import {helperMethod} from '../1.js'; do not work

Note it works perfectly fine when the file is in the same folder: e.g import {helperMethod} from './1.js';


Going to attach file subfolderbugrepro.zip to reproduce


Actual results:


What is strange, is that there is no Error displayed at all in the console.


Expected results:

import works or at least error

Comment 1

[Kagami Rosylight [:saschanaz] (they/them)]

Now I can see a warning message:

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at file:///C:/Users/sasch/Desktop/test/1.js. (Reason: CORS request not http).

The behavior difference when in the same folder still exists.

Comment 2

[Kagami Rosylight [:saschanaz] (they/them)]

Now all import fails by default with file:/// to make sure any malicious HTML file can't access arbitrary files in the same directory. Turning off privacy.file_unique_origin restores the previous behavior.