makeTest is the internal function used to evaluate the result of a check and throw an exception if necessary. This function is currently only a stub and just calls isTRUE. makeTestFunction can be used to automatically create an assertion function based on a check function (see example).


makeTestFunction(, = NULL, env = parent.frame())



[TRUE | character(1)]
The result of a check function: TRUE for successful checks, and an error message as string otherwise.

Function which checks the input. Must return TRUE on success and a string with the error message otherwise.

If not NULL, instead of calling the function, use .Call to call a C function “” with the identical set of parameters. The C function must be registered as a native symbol, see .Call. Useful if is just a simple wrapper.


The environment of the created function. Default is the parent.frame.


makeTest returns TRUE if the check is successful and FALSE otherwise. makeTestFunction returns a function.

See also

Other CustomConstructors: makeAssertion(), makeExpectation()


# Simple custom check function
checkFalse = function(x) if (!identical(x, FALSE)) "Must be FALSE" else TRUE

# Create the respective test function
testFalse = function(x) {
  res = checkFalse(x)

# Alternative: Automatically create such a function
testFalse = makeTestFunction(checkFalse)
#> function (x) 
#> {
#>     isTRUE(checkFalse(x))
#> }
#> <environment: 0x7fcdf5a0dba8>