expect_is: Does an object inherit from a given class?

View source: R/expect-inheritance.R

expect_isR Documentation

Does an object inherit from a given class?



expect_is() is an older form that uses inherits() without checking whether x is S3, S4, or neither. Instead, I'd recommend using expect_type(), expect_s3_class() or expect_s4_class() to more clearly convey your intent.


expect_is(object, class, info = NULL, label = NULL)



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.


Either a character vector of class names, or for expect_s3_class() and expect_s4_class(), an NA to assert that object isn't an S3 or S4 object.

3rd edition


expect_is() is formally deprecated in the 3rd edition.

testthat documentation built on Oct. 6, 2023, 5:10 p.m.