Best Way to Assert That Each String in a Collection Contains a Substring?

Question

What is the best way to assert that each element in a collection of strings contains a particular substring?

Something like

List<String> list = Arrays.asList("xyfoobar", "foobarxy", "xyfoobarxy");

assertThat(list, eachElementContains("foobar")); // pass

Answer 1

A simple solution is to use hamcrest library. Please try :

import static org.hamcrest.CoreMatchers.containsString;
import static org.hamcrest.CoreMatchers.everyItem;

import java.util.Arrays;
import java.util.List;

import org.junit.Test;

public class MyTest {

    @Test
    public void test() {
        List<String> list = Arrays.asList("xyfoobar", "foobarxy", "xyfoobarxy");
        assertThat(list, (everyItem(containsString("foobar"))));
    }
}