assert_engine: Throws an error if a condition isn't met.
Description
The workhorse of the package. If a condition isn't met, then an error
is thrown.Usage
assert_engine(x, predicate, msg, what = c("all", "any"), ...)Arguments
x
Input to check. If missing, pass no args to predicate.
predicate
Function that returns a logical value (possibly
a vector).
msg
The error message, in the event of failure.
what
Either 'all' or 'any', to reduce vectorised tests to a
single value.
...
Passed to the predicate function.
Value
FALSE with the attribute message, as provided
in the input.