Prettier 3.6.2
Playground link

--parser acorn

Input:

func(() => // comment
(a , b , c))


func(
  () =>
    (
      // comment
      a, b, c
    ),
);

(
  // comment
  a, b, c
);

Output:

func(
  () =>
    // comment
    (a, b, c),
);

func(
  () =>
    // comment
    (a, b, c),
);

// comment
(a, b, c);

Expected output:

1. Place comments inside the sequence expression

func(
  () =>
    (
      // comment
      a, b, c
    ),
);

func(
  () =>
    (
      // comment
      a, b, c
    ),
);

(
  // comment
  a, b, c
)

2. Keep the comments place as-is

func(
  () =>
    // comment
    (a, b, c),
);

func(
  () =>
    (
      // comment
      a, b, c
    ),
);

(
  // comment
  a, b, c
)

Why?

I think the comment, if the sequence expression wraps it, then the output should keep it in the same place. However, it was placed before the sequence expression anyway.

Not sure which output is better, here are my thoughts on the two different results:

1. The first one maintains consistency as long as the comments precede the first expression of the sequence.
2. The second one keeps the comments in the same place as the input.