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Test Writing: Subtracter with Lambda

Created By: Geoffrey Challen
/ Version: 2021.2.0

Declare a method named subtracter. subtracter takes a single Int parameter and returns a method that implements the Modify functional interface:

The returned "function" should implement modify so that it returns the argument passed to subtracter minus the argument to modify. So, for example:

The correct solution to this problem is a single line lambda expression!

Test Design Challenge

You're challenge is to write tests for this problem described above.

  • Provide a public class named TestModifier with a single non-private class method named test that accepts no arguments and does not return a value.
  • If the implementation of the class described above is incorrect, your test method should throw an exception.
  • If it is correct, do not throw an exception.
  • You may want to use Kotlin's assert or check methods