paste0() incorrectly uses a sep argument

[DavisVaughan]

My wife was confused by the fact that paste0(sep =) was actually translating the same way as paste(sep =). Turns out that in our translation, we accept the sep named argument in both cases, when really we should treat sep = as part of the ... in the case of paste0() translations (or maybe even warn if we see paste0(sep =)?).

library(dbplyr)
library(dplyr, warn.conflicts = FALSE)

con <- simulate_postgres()
df <- lazy_frame(a = "x", b = "y", con = con)

# This is not right!
df |>
  mutate(c = paste0(a, b, sep = "_"))
#> <SQL>
#> SELECT *, CONCAT_WS('_', `a`, `b`) AS `c`
#> FROM `df`

^{Created on 2024-03-05 with reprex v2.0.2}