[wleeaf]

The paren_expr printer drops parentheses around a function argument. When the parentheses hold a list, the list is a single row constructor, so dropping them turns one argument into several and changes which function is called:

SELECT array_position(ids, (1, 1)) FROM tbl

is formatted as

SELECT array_position(ids, 1, 1) FROM tbl

This is a different call: array_position(anyarray, anyelement, integer) with a start position, instead of searching for the row (1, 1).

The parentheses are now kept when they contain a list_expr, the same way they are already kept for subqueries and for DISTINCT (...) (#32, #73). Parentheses around other single arguments are still removed (my_func((id), (name)) still becomes my_func(id, name)).

Test: "preserves parenthesis around row constructor inside function arguments" in test/expr/expr.test.ts (PostgreSQL). It fails without the change and passes with it. yarn test passes (1060 passed, 1 skipped), as do yarn ts:check and prettier --check on the changed files.

I found this by formatting the statements of PostgreSQL's regression tests with the postgresql parser and comparing the libpg_query parse tree of each output with that of the input.