Subject: Re: bug#71992: 30.0.60; major-mode-remap-alist doesn't work for combination js-mode + js-ts-mode

From: Dmitry Gutov <[email-masked]>
Date: Tue, 9 Jul 2024 02:55:48 +0300

On 09/07/2024 00:37, Jeremy Bryant via Bug reports for GNU Emacs, the 
Swiss army knife of text editors wrote:
> Roman Rudakov<[email-masked]>  writes:
> 
>> 1. Evaluate: (setopt major-mode-remap-alist '((js-mode . js-ts-mode)))
>> 2. C-x C-f ~/tmp.js
>>
>> Expected result:
>>
>> major-mode is js-ts-mode
>>
>> Actual result:
>>
>> major-mode is js-mode
>>
>>
>> In GNU Emacs 30.0.60 (build 1, aarch64-apple-darwin23.5.0, NS
>> appkit-2487.60 Version 14.5 (Build 23F79)) of 2024-07-06 built on
>> Romans-MBP.home
>> Windowing system distributor 'Apple', version 10.3.2487
>> System Description:  macOS 14.5
>>
> FWIW, I've been able to reproduce this bug report in 30.0.60 and 29.4

The reason might be that its auto-mode-alist entry references 
javascript-mode (and js-mode is made an alias in autoloads).