Assert that conditions are met

Assert that conditions are met

Usage

assert(..., msg = NULL, call = rlang::caller_env())

Arguments

...

a list of conditions to check

msg

A character string containing the error message to display if any of the conditions are not met. The string can include the placeholder {failed_expressions} to insert a list of the failed expressions. The string can also include {?s} and {?is/are} to insert the correct pluralization for the list of failed expressions.

call

Only relevant when pooling assertions into multi-assertion helper functions. See cli_abort for details.

Value

invisible(TRUE) if all conditions are met, otherwise aborts with the error message specified by msg

Examples

try({
assert(1 == 1) # Passes
assert(2 == 2, 3 == 3) # Passes
assert(2 == 1, 3 == 3) # Throws default error
assert(2 == 1, 3 == 3, msg = "Custom error message") # Throws custom error
})
#> Error in eval(expr, envir) : The following assertions failed:
#> ✖ `2 == 1`