Nested comments can transpile to invalid sql

[patricksurry]

I'm using python3 -m sqlglot --read bigquery --write bigquery - < foo.sql.

I've run into this issue a few times via sqlmesh format ... after commenting out a line using -- which contained a trailing comment (typically previously formatted by sqlmesh).

bigquery SQL doesn't seem to allow nested /* */ pairs so flags the second */ in the output as invalid.

Input (valid sql):

select
    id,
    foo,
    -- bar, /* the thing */
from facts

output (invalid sql):

SELECT
  `id`,
  `foo`
/* bar, /* the thing */ */
FROM `facts`

[georgesittas]

Interesting one, thanks. May be tricky to fix but we'll take a closer look here as well.