A for loop compiles incorrectly in WHITESPACE_ONLY and SIMPLE_OPTIMIZATIONS

[jplevene]

A for(const row of rows) returns $jscomp and loads of junk JavaScript code that won't run.

[jplevene]

Even does this in WHITESPACE_ONLY that is not supposed to alter the code

[lauraharker]

This is caused by transpilation. See #3856 and #2007.

Compiler versions past ac3e330 will default to not transpiling. If you're using an older version you can set --language_out=ECMASCRIPT_NEXT. If you're using a newer version, are you setting --language_out explicitly? You'd need to remove that.

[jplevene]

I spotted this bug in the Google online compiler https://closure-compiler.appspot.com/ which is managed by Google so I reported this, and thanks.
By default, clicking "Whitespace only" in the online compiler should include the line // @language_out ECMASCRIPT_NEXT which is causing the issue.
Again, thanks for this and I have reported the bug there