bug#74386: Tree-sitter javascript indentation

[Dmitry Gutov <dmitry@gutov.dev>]

On 17/11/2024 21:21, Marius Kjeldahl wrote:
> Great, thanks.
> 
> Here are two examples (fingers crossed):
> 
> function a(b,
>    c) {
> ....d();
> 
> and
> 
> if (clause1
>    && clause2) {
> ....callSomeFunc();
> 
> Notice in both cases the four dots "...." representing spaces used for
> indentation. I would like only two dots (two spaces) for those
> specific examples.

Thank you, these two examples should be handled by the patch below.

It's a change which could affect a fair amount of other examples too - 
for example

Foobar
   .find()
   .catch((err) => {
     return 2;
   })
   .then((num) => {
     console.log(num);
   });

turns into

Foobar
   .find()
   .catch((err) => {
   return 2;
})
   .then((num) => {
   console.log(num);
});


I'm not 100% sure if that's good or bad (maybe worse compatibility with 
js-mode, that we could say), so it would be useful to go through a bunch 
of other examples and decide whether what we had is a bug, or these 
should be supported as different styles, or etc.

Cc'ing the original author of js-ts-mode, Theodor, for consultation.

BTW, to try out such a patch you need to apply it, evaluate the defvar 
form (C-M-x, for example), and then re-enable the major mode in a given 
buffer (M-x js-ts-mode).

diff --git a/lisp/progmodes/js.el b/lisp/progmodes/js.el
index f74b8ab1c46..17a9509dd45 100644
--- a/lisp/progmodes/js.el
+++ b/lisp/progmodes/js.el
@@ -3453,7 +3453,7 @@ js--treesit-indent-rules
    (let ((switch-case (rx "switch_" (or "case" "default"))))
      `((javascript
         ((parent-is "program") parent-bol 0)
-       ((node-is "}") parent-bol 0)
+       ((node-is "}") standalone-parent 0)
         ((node-is ")") parent-bol 0)
         ((node-is "]") parent-bol 0)
         ((node-is ">") parent-bol 0)
@@ -3466,7 +3466,7 @@ js--treesit-indent-rules
         ;; "{" on the newline.
         ((node-is "statement_block") parent-bol js-indent-level)
         ((parent-is "named_imports") parent-bol js-indent-level)
-       ((parent-is "statement_block") parent-bol js-indent-level)
+       ((parent-is "statement_block") standalone-parent js-indent-level)
         ((parent-is "variable_declarator") parent-bol js-indent-level)
         ((parent-is "arguments") parent-bol js-indent-level)
         ((parent-is "array") parent-bol js-indent-level)
@@ -3481,7 +3481,6 @@ js--treesit-indent-rules
         ((parent-is "binary_expression") parent-bol js-indent-level)
         ((parent-is "class_body") parent-bol js-indent-level)
         ((parent-is ,switch-case) parent-bol js-indent-level)
-       ((parent-is "statement_block") parent-bol js-indent-level)
         ((match "while" "do_statement") parent-bol 0)
         ((match "else" "if_statement") parent-bol 0)
         ((parent-is ,(rx (or (seq (or "if" "for" "for_in" "while" "do") 
"_statement")