Cannot convert vector of different formats to POSIXct

I have a dataset containing a date in CHAR format that I want to convert to POSIXct. The dates are always in one of five formats, but for this example two will suffice:

test <- c("15/03/19 17:16", "15/03/19,17:16", "15/03/19,17:16")
formats <- c(
    "%d/%m/%y,%H:%M",
    "%d/%m/%y %H:%M",
    "%d/%m/%Y,%H:%M",
    "%d/%m/%Y %H:%M",
    "%Y%m%d%H%M%S"
)

as.POSIXct(test[1], tz = "GMT", tryFormats = formats) # works
as.POSIXct(test[2:3], tz = "GMT", tryFormats = formats) # works
as.POSIXct(test, tz = "GMT", tryFormats = formats)    # fails

Individually, the two dates convert without issue. When the vector (or in my case, the datatable via mutate) is put through as.POSIXct the following error is generated:

Error in as.POSIXct.character(x, tz, ...) : character string is not in a standard unambiguous format

Presumably as.POSIXct is picking only one of the formats in tryFormat and trying to apply that to the whole set, which won't work.

Is my only option here creating a blank column and manually looping through each individual row to populate it?

Example dates:

15/03/19 17:16
15/03/19,17:16
15/03/2019 17:16
15/03/2019,17:16
20190315171600GS

Solution

Try lubridate::dmy_hm which works for both. Also your formats needs correction I believe.

formats <- c("%d/%m/%y,%H:%M", "%d/%m/%y %H:%M")

lubridate::dmy_hm(test)
#[1] "2019-03-15 17:16:00 UTC" "2019-03-15 17:16:00 UTC" "2019-03-15 17:16:00 UTC"

Or with anytime

anytime::addFormats(formats)
anytime::anytime(test)

If we need to specify formats explicitly, we may also use parse_date_time

lubridate::parse_date_time(test, formats)