Outdated exception message and unreachable code using offset_by's roll argument

[SebastienFries]

In version 3.16, the offset_by takes roll as argument but:

• [outdated exception message] when roll is omitted and offset_by("1bd")is being applied on a column containing non-business dates, an outdated error message is raised: "'roll' argument is coming soon".

• [bug] when roll is used with an improper value: "internal error: entered unreachable code"

import polars as pl
import polars_business as plb
import datetime

df = pl.DataFrame({
"date": pl.date_range(datetime.date(2023,12,1), datetime.date(2023,12,5), eager=True)
})

df.with_columns(pl.col("date").bdt.offset_by("1bd"))  # this will return the outdated exception message

df.with_columns(pl.col("date").bdt.offset_by("1bd", roll="forward"))  # this will work as expected

df.with_columns(pl.col("date").bdt.offset_by("1bd", roll="cabbage"))  # this will enter unreachable code

[MarcoGorelli]

thanks @SebastienFries for the report, this is fixed in the latest version (0.3.18)