Where is the declaration of JUnit Matcher#startsWith?
import static org.hamcrest.core.StringStartsWith.startsWith;
enables both
assertThat(msg, startsWith ("what"));
and
ExpectedException.none().expectMessage(startsWith("What")); //HERE
Most likely this is the startsWith
method from the Hamcrest org.hamcrest.Matchers
class.
Looking at ExpectedException, we can see that there are two expectMessage methods defined, one String and one Matcher, which is indeed org.hamcrest.Matcher
.
/**
* Adds to the list of requirements for any thrown exception that it should
* <em>contain</em> string {@code substring}
*/
public void expectMessage(String substring) {
expectMessage(containsString(substring));
}
/**
* Adds {@code matcher} to the list of requirements for the message returned
* from any thrown exception.
*/
public void expectMessage(Matcher<String> matcher) {
expect(hasMessage(matcher));
}