Java String split behavior

StringTest.java

import org.junit.Test;

import static org.assertj.core.api.Assertions.assertThat;

public class StringTest {
    @Test
    public void empty_regex_on_empty_char() {
        assertThat("".split("")).isEqualTo(new String[]{""});
    }

    @Test
    public void empty_regex_cuts_each_char() {
        assertThat("abc".split("")).isEqualTo(new String[]{"a", "b", "c"});
    }

    @Test
    public void cuts_empty_string_to_empty_component() {
        assertThat("".split(":")).isEqualTo(new String[]{""});
    }

    @Test
    public void do_not_cut_when_input_equals_regex() {
        assertThat(":".split(":")).isEqualTo(new String[]{});
    }

    @Test
    public void cut_into_one_component() {
        assertThat("A".split(":")).isEqualTo(new String[]{"A"});
    }

    @Test
    public void suffix_input_by_regex_cut_into_one_component() {
        assertThat("A:".split(":")).isEqualTo(new String[]{"A"});
    }

    @Test
    public void prefix_input_by_regex_cuts_into_two_components() {
        assertThat(":A".split(":")).isEqualTo(new String[]{"", "A"});
    }
}