checkmate (version 1.7.3)

checkFunction: Check if an argument is a function

Description

Check if an argument is a function

Usage

checkFunction(x, args = NULL, ordered = FALSE, nargs = NULL)
assertFunction(x, args = NULL, ordered = FALSE, nargs = NULL,
  add = NULL, .var.name = NULL)
assert_function(x, args = NULL, ordered = FALSE, nargs = NULL,
  add = NULL, .var.name = NULL)
testFunction(x, args = NULL, ordered = FALSE, nargs = NULL)
test_function(x, args = NULL, ordered = FALSE, nargs = NULL)
expect_function(x, args = NULL, ordered = FALSE, nargs = NULL,
  info = NULL, label = NULL)

Arguments

x

[any] Object to check.

args

[character] Expected formal arguments. Checks that a function has no arguments if set to character(0). Default is NULL (no check).

ordered

[logical(1)] Flag whether the arguments provided in args must be the first length(args) arguments of the function in the specified order. Default is FALSE.

nargs

[integer(1)] Required number of arguments, without .... Default is NULL (no check).

add

[AssertCollection] Collection to store assertions. See AssertCollection.

.var.name

[NULL || character(1)] Name of the checked object to print in error message. If NULL, the name will be heuristically determined via substitute.

info

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

label

[character(1)] Same as .var.name, but passed down to expect_that.

Value

• Depending on the function prefix: If the check is successful, the functions return TRUE. If the check is not successful, assertFunction/assert_function throws an error message, testFunction/test_function returns FALSE, and checkFunction returns a string with the error message. The function expect_function always returns an expectation.

See Also

Other basetypes: checkArray, checkAtomicVector, checkAtomic, checkCharacter, checkComplex, checkDataFrame, checkDataTable, checkEnvironment, checkFactor, checkIntegerish, checkInteger, checkList, checkLogical, checkMatrix, checkNumeric, checkVector

Examples

testFunction(mean)
testFunction(mean, args = "x")