Check the class membership of an argument

Check the class membership of an argument

checkClass(x, classes, ordered = FALSE, null.ok = FALSE)

check_class(x, classes, ordered = FALSE, null.ok = FALSE)

assertClass(
  x,
  classes,
  ordered = FALSE,
  null.ok = FALSE,
  .var.name = vname(x),
  add = NULL
)

assert_class(
  x,
  classes,
  ordered = FALSE,
  null.ok = FALSE,
  .var.name = vname(x),
  add = NULL
)

testClass(x, classes, ordered = FALSE, null.ok = FALSE)

test_class(x, classes, ordered = FALSE, null.ok = FALSE)

expect_class(
  x,
  classes,
  ordered = FALSE,
  null.ok = FALSE,
  info = NULL,
  label = vname(x)
)

Arguments

x

[any]
Object to check.

classes

[character]
Class names to check for inheritance with inherits. x must inherit from all specified classes.

ordered

[logical(1)]
Expect x to be specialized in provided order. Default is FALSE.

null.ok

[logical(1)]
If set to TRUE, x may also be NULL. In this case only a type check of x is performed, all additional checks are disabled.

.var.name

[character(1)]
Name of the checked object to print in assertions. Defaults to the heuristic implemented in vname.

add

[AssertCollection]
Collection to store assertion messages. See AssertCollection.

info

[character(1)]
Extra information to be included in the message for the testthat reporter. See expect_that.

label

[character(1)]
Name of the checked object to print in messages. Defaults to the heuristic implemented in vname.

Value

Depending on the function prefix: If the check is successful, the functions

assertClass/assert_class return

x invisibly, whereas

checkClass/check_class and

testClass/test_class return

TRUE. If the check is not successful,

assertClass/assert_class

throws an error message,

testClass/test_class

returns FALSE, and checkClass/check_class

return a string with the error message. The function expect_class always returns an

expectation.

See also

Other attributes: checkMultiClass(), checkNamed(), checkNames()

Other classes: checkMultiClass(), checkR6()

Examples

# Create an object with classes "foo" and "bar"
x = 1
class(x) = c("foo", "bar")

# is x of class "foo"?
testClass(x, "foo")
#> [1] TRUE

# is x of class "foo" and "bar"?
testClass(x, c("foo", "bar"))
#> [1] TRUE

# is x of class "foo" or "bar"?
if (FALSE) {
assert(
  checkClass(x, "foo"),
  checkClass(x, "bar")
)
}
# is x most specialized as "bar"?
testClass(x, "bar", ordered = TRUE)
#> [1] FALSE