Java Coding Problems

Testing a method that takes a lambda as a parameter

Testing a method that takes a lambda as a parameter can be accomplished by passing different lambdas to this method. For example, let's assume that we have the following functional interface:

@FunctionalInterfacepublic interface Replacer<String> {  String replace(String s);}

Let's also assume that we have a method that takes lambdas of the String -> String type, as follows:

public static List<String> replace(    List<String> list, Replacer<String> r) {  List<String> result = new ArrayList<>();  for (String s: list) {    result.add(r.replace(s));  }  return result;}

Now, let's write a JUnit test for this method using two lambdas:

@Testpublic void testReplacer() throws Exception { List<String> names ...