Assert that a condition is false — assert_false • assert

The counterpart of assert_true(). condition must be a single FALSE.

Usage

assert_false(
  condition,
  message = NULL,
  arg = rlang::caller_arg(condition),
  call = rlang::caller_env()
)

Arguments

condition: A single logical value that must be TRUE.
message: Optional custom error message. If omitted, a generic message naming the condition expression is used.
arg: Name used to refer to condition in the default error message. Defaults to the condition expression.
call: Environment used as the error's call context. Defaults to the calling function, so errors point at the user's code.

Value

The input condition, invisibly.

Examples

x <- 5
assert_false(x < 0)