Package index • assertthat

All functions
`are_equal()`	Are two objects equal?
`is.error()` `is.time()` `is.date()`	Missing is functions.
`assert_that()` `see_if()`	Assert that certain conditions are true.
`is.dir()` `is.writeable()` `is.readable()` `has_extension()`	Useful test related to files
`has_args()` `%has_args%`	Check a function has specified arguments
`has_attr()` `%has_attr%` `has_name()` `%has_name%`	Has attribute or name?
`noNA()`	Does object contain any missing values?
`not_empty()`	Check an object doesn't have any empty dimensions
`on_failure()` `on_failure<-`()	Custom failure messages for assertions.
`is.scalar()` `is.string()` `is.number()` `is.flag()` `is.count()`	Assert input is a scalar.
`validate_that()`	Validate that certain conditions are true.

Reference