testthat (version 0.6)

is_a: Expectation: does the object inherit from a class?

Description

Tests whether or not an object inherits from any of a list of classes.

Usage

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

Arguments

class

character vector of class names

object

object to test

info

extra information to be included in the message (useful when writing tests in loops).

label

object label. When NULL, computed from deparsed object.

See Also

inherits

Other expectations: equals, expect_equal, expect_equivalent, expect_error, expect_false, expect_identical, expect_match, expect_message, expect_output, expect_true, expect_warning, gives_warning, is_equivalent_to, is_false, is_identical_to, is_true, matches, prints_text, shows_message, takes_less_than, throws_error

Examples

expect_that(1, is_a("numeric"))
a <- matrix(1:10, nrow = 5)
expect_that(a, is_a("matrix"))

expect_that(mtcars, is_a("data.frame"))
expect_is(mtcars, "data.frame")
# alternatively for classes that have an is method
expect_that(is.data.frame(mtcars), is_true())
# doesn't read quite as nicely