Expect that a condition holds.

Source: R/expect-that.R

Superseded lifecycle

An old style of testing that's no longer encouraged.

expect_that(object, condition, info = NULL, label = NULL)

Arguments

object

Object to test.

Supports limited unquoting to make it easier to generate readable failures within a function or for loop. See quasi_label for more details.
condition,

a function that returns whether or not the condition is met, and if not, an error message to display.
info

Extra information to be included in the message. This argument is soft-deprecated and should not be used in new code. Instead see alternatives in quasi_label.
label

Used to customise failure messages. For expert use only.

Value

the (internal) expectation result as an invisible list

3rd edition

Deprecated lifecycle

This style of testing is formally deprecated as of the 3rd edition. Use a more specific expect_ function instead.

See also

fail() for an expectation that always fails.

Examples

expect_that(5 * 2, equals(10))

#> Warning: `expect_that()` was deprecated in the 3rd edition.
expect_that(sqrt(2) ^ 2, equals(2))

#> Warning: `expect_that()` was deprecated in the 3rd edition.
if (FALSE) {
expect_that(sqrt(2) ^ 2, is_identical_to(2))
}