json_format(to_json()) fails (trino -> spark)

[joshmarcus]

When translating SQL like json_format(to_json(column)) from read='trino' to write='spark', it's translated as:
TO_JSON(TO_JSON(column)) which fails in SparkSQL, as TO_JSON doesn't accept the return type of TO_JSON.

query = "select json_format(to_json(column)) from table"
sqlglot.transpile(query, read="trino", write="spark")

returns

['SELECT TO_JSON(TO_JSON(column)) FROM table']

expected:

['SELECT TO_JSON(column) FROM table']

[joshmarcus]

Locally, I just drop JSON_FORMAT() instead of converting it to TO_JSON().

[georgesittas]

I can take a look soon, but it seems that TO_JSON is not in Trino's docs and indeed it throws an error for me:

trino> SELECT json_format(to_json('[1, 2, 3]'));
Query 20230504_171741_00002_uihyy failed: line 1:20: Function 'to_json' not registered
SELECT json_format(to_json('[1, 2, 3]'))

It works with SELECT JSON_FORMAT(JSON '[1, 2, 3]'), although it's not parsed correctly atm in SQLGlot.