Change comment style in web-mode

Question

I am using web-mode 20161003.1327

At the moment when I comment a region in web-mode, it comments like this;

/* import chai from 'chai';
 * import 'babel-polyfill';
 * import configureMockStore from 'redux-mock-store';
 * import thunk from 'redux-thunk';
 * import * as ActionTypes from '../actions/ForecastActions';
 * 
 * const expect = chai.expect;
 * 
 * const middlewares = [ thunk ];
 * const mockStore = configureMockStore(middlewares);
 * 
 * /

This is not good for uncommenting only a section.

Can I change the commenting to use double forward slash?

I've tried using (setq web-mode-comment-style 2) but this appears to do nothing.

I have also tried web-mode-comment-formats but it also does not appear to work:

(require 'web-mode)

(add-to-list 'web-mode-comment-formats '("javascript" . "//"))

(defun my-web-mode-hook ()
  "web-mode settings"
  (setq web-mode-markup-indent-offset 2)
  (setq web-mode-css-indent-offset 2)
  (setq web-mode-code-indent-offset 2))

(add-hook 'web-mode-hook  'my-web-mode-hook)

(add-to-list 'auto-mode-alist '("\\.html?\\'" . web-mode))
(add-to-list 'auto-mode-alist '("\\.js?$" . web-mode))

Answer 1

web-mode-comment-formats is a buffer local variable. Also, add-to-list may not work correctly, since there is already a mapping for javascript to /*.

You can try one of the following:

(setq-default web-mode-comment-formats
              (remove '("javascript" . "/*")
                      web-mode-comment-formats))
(add-to-list 'web-mode-comment-formats '("javascript" . "//"))

Or

(setq-default web-mode-comment-formats
              '(("java"       . "/*")
                ("javascript" . "//")
                ("php"        . "/*")))