Changelog • arg

*arg (development version)

Fixed bug in nested arg_or()/arg_and() introduced in previous version. Such errors render much more cleanly.
Nested errors are formatted more cleanly when used with when_not_null() and when_supplied().

CRAN release: 2026-07-15

Added arg_color() (and variants) to check whether an argument corresponds to a valid color specification.
Added arg_name() and arg_names() to check whether an argument is a vector of valid names of elements of an object.
Added arg_ordered() to check whether an argument is an ordered factor.
arg_index() and arg_indices() now check names for arbitrary objects, not just matrices and data frames.
arg_counts() and arg_whole_numeric() (and their scalar equivalents) now check whether a value is a whole number using rlang::is_integerish() instead of the criterion used by all.equal().
Fixed a bug where the message provided to .msg (if any) was not evaluated in the correct environment.
Fixed several typos in the documentation and in some error messages.
Fixed bugs in processing some complicated nested messages produced by arg_and() and arg_or().
Added a new logo.
Added a testing suite.

CRAN release: 2026-05-27

err(), wrn(), and msg() now pass arguments specified in ... to rlang::abort(), rlang::warn(), and rlang::inform(), respectively.
When an error is caused by a failure to process a given fixed argument (e.g., bounds in arg_gt() or len in arg_length()), that error is now thrown correctly in arg_or(), arg_and(), when_supplied(), and when_not_null(). Previously, it was bundled with the errors thrown to the ultimate user of the function and_or(), etc., was used in, which it made it confusing to diagnose.
Fixed bugs with arg_or(), arg_and(), when_supplied(), and when_not_null().
Fixed a bug where an extra period might be added after an error message.
When the empty string ("") is supplied to err(), etc., it is no longer appended with a period.
Improved error messages for arg_element() and arg_not_element().
The .msg argument of arg_*() functions is now checked to ensure it is a string when not NULL.

CRAN release: 2026-04-09