bug#15582: notes on js-mode indentation bug

[Dmitry Gutov]

On 10.01.2017 08:03, Tom Tromey wrote:

> It would be helpful to know when the continued-expr-p branch really is
> supposed to trigger.  Or, if there is an informal corpus of indentation
> tests, it would be nice to put them all into js-tests.el.

It triggers, for instance, in this example:

b +=
  c

But you have probably found it already.

> Tom
>
> diff --git a/lisp/progmodes/js.el b/lisp/progmodes/js.el
> index 1484b79..0551f2a 100644
> --- a/lisp/progmodes/js.el
> +++ b/lisp/progmodes/js.el
> @@ -1771,6 +1771,24 @@ js--looking-at-operator-p
>                   ;; return NaN anyway.  Shouldn't be a problem.
>                   (memq (char-before) '(?, ?} ?{))))))))
>
> +(defun js--find-newline-backward ()
> +  "Move backward to the nearest newline that is not in a block comment."

You might want to phrase it like "Move ... ignoring comments.", meaning 
treating the openers of non-block comments as newlines, and the contents 
of block comments as entirely invisible.

BTW, here are a couple of examples that the new fix doesn't handle:

b += /* found */
  c

b += /*
   */
  c

(I think they suggest that the block comment-related behavior of the new 
function might be tweaked a little).

Thanks.