Mockito verify argument contains another string ignoring case

Question

What I've got is this line:

verify( mockAppendable ).append( org.mockito.Mockito.contains( msg ) );

... but I want this test to be case-indifferent. How would I do that?

Answer 1

On the page, what do they mean by "you can extract method" and is it possible to use a Java 8 lambda to make this a one-liner?

In a single line using case insensitivity code from here:

verify(mockAppendable)
    .append(
       argThat(arg ->
         Pattern.compile(Pattern.quote(msg), Pattern.CASE_INSENSITIVE).matcher(arg).find()));

So they allowed the lambda version by skipping specifying a custom error message.

And by "you can extract a method", they mean:

verify(mockAppendable).append(argThat(containsCaseInsensitive(msg)));

And the method is defined as:

public static ArgumentMatcher<String> containsCaseInsensitive(final string s) {
    if (s == null) throw new IllegalArgumentException("s is null");
    final Pattern pattern = Pattern.compile(Pattern.quote(s), Pattern.CASE_INSENSITIVE);
    return new ArgumentMatcher<String>() {

        @Override
        public boolean matches(String arg) {
            return arg != null && pattern.matcher(arg).find();
        }

        @Override 
        public String toString() {
            return String.format("[should have contained, ignoring case, \"%s\"]", s);
        }
    };
}

That's completely reusable, you can put that inside a new class like MocitoMatchers for example and call from many tests just like any of the built-in matchers.