Idempotency error on `pure A.{x}` within a function

[Niols]

As of 439f0d1:

with_
  (fun x ->
     pure A.{x})

I don't even understand why Topiary is trying to multi-line pure A.{x} and I think it should not, if only for consistency with other places.

Logs:

[2025-09-03T10:34:01Z ERROR topiary_core] Failed idempotence check
[2025-09-03T10:34:01Z ERROR topiary_core] Diff < left / right > :
     with_
       (fun x ->
    <    pure A.{
    <      x
    <    }
    >    pure
    >      A.{
    >        x
    >      }
       )
     
    
[2025-09-03T10:34:01Z ERROR topiary] The formatter did not produce the same
    result when invoked twice (idempotence check).
    
    If this happened with the built-in query files, it is a bug. It would be
    helpful if you logged this error at
    https://github.com/tweag/topiary/issues/new?assignees=&labels=type%3A+bug&template=bug_report.md

[Niols]

I don't think it has to do with the function per se but with the parentheses instead.

[Niols]

I must say I have been facing an idempotency error almost daily these days. Usually, they aren't so hard to work around, like in this case I just committed:

with_
  (fun x ->
     pure
       A.{
         x
       }
  )

but that is a bit concerning (and, in this case, the result is ugly).