Loading Blockly as ES6 module creates a global object

[seldomU]

Describe the bug

Importing Blockly as a module should add a Blockly object to the scope of the script that imports it. But there is a second Blockly object created that gets added to the global window object. It contains Msg entries.

To Reproduce

Run the the webpack example server, load the index page, use the debugger to pause the page and inspect the scopes. In Chrome I could only see the global scope, Firefox shows more.

Expected behavior

There should only be one Blockly object. I stumbled over this because my unusual block loading method resulted in blockdefinitions being devided between the two Blockly objects. JavaScript definitions landed in one, JSON definitions in the other.

Desktop (please complete the following information):

• OS: windows 10
• Browser: Chrome 85 & Firefox 81

[samelhusseini]

The behaviour that you're seeing makes sense to me, but unfortunately there's not a lot that we can do about it if we want to continue to support ADVANCED_COMPILATION.

Blockly exports the Blockly.Msg variable for closure ADVANCED_COMPILATION support, such that it doesn't get renamed, and message files can be used alongside Blockly.

As a workaround, if the global Blockly object is causing you trouble, it should be safe to set it to undefined after you've imported Blockly. eg:

import * as Blockly from 'blockly';
window.Blockly = undefined;

[seldomU]

Thank you, I'll try that.