bug#66988: 30.0.50; treesit-forward-sexp not working properly in js-ts-mode and tsx-ts-mode

[Yuan Fu]

> On Nov 9, 2023, at 5:41 PM, Dmitry Gutov <dmitry@gutov.dev> wrote:
> 
> Hi!
> 
> On 07/11/2023 16:56, Loïc Lemaître wrote:
>> Hi Emacs team,
>> Here the steps to demonstrate the bug :
>> 1. Compile Emacs from master branch with tree-sitter support
>> 2. Install javascript and tsx languages
>> 3. Run Emacs
>> 4. Create a new buffer
>> 5. Turn major mode to either js-ts-mode or tsx-ts-mode
>> 6. Past the following content into the buffer:
>> (
>>   <div>
>>   </div>
>> );
>> 7. Place point before opening parenthese
>> 8. M-x forward-sexp (which will call treesit-forward-sexp)
>> => New position is right after the semi-colon instead of being before the 
>> semi-colon.
>> Note that the bug disappear if the buffer content is changed for :
>> const component = (
>>   <div>
>>   </div>
>> );
>> But previous content, while not being very usefull, is valid JSX, as far as 
>> I know.
>> I use this syntax for unit test purpose, since it is very short.
> 
> Thanks for the report.
> 
> The patch below should fix it.
> 
> Yuan, what do you think? A similar change (bos and eos anchors) might be 
> useful for other things and other modes.
> 
> Alternatively, treesit-thing-settings could be interpreted to imply full 
> matches, then the code using it should not only match against the regexps but 
> also check that the entire string (type name) is matched.

I regret not doing this by default for treesit-indent-rules and traverse 
functions. Now it’s hard to change without creating confusion and breaking 
backward compatibility. I wonder if there are good way to smoothly transition 
to match full names by default…

Treesit-thing-settings can be changed to match full names, but only if we can 
change treesit-indent-rules and friends too. Otherwise it would be too 
confusing.

Yuan