@Test
public void getNextPage_returnsFullNextPage_whenItIsNotAFullFirstPage() throws Exception {
final Page page = new Page(3, 5);
final Page nextPage = page.getPreviousPage().getNextPage();
assertThat(nextPage).isNotNull();
assertThat(nextPage.getStart()).isEqualTo(3);
assertThat(nextPage.getSize()).isEqualTo(5);
}
@Test
public void getPreviousPage_returnsEmptyPage_whenItIsAlreadyEmptyPage() throws Exception {
final Page page = new Page(0, 5);
final Page previousPage = page.getPreviousPage().getPreviousPage();
assertThat(previousPage).isNotNull();
assertThat(previousPage.getStart()).isEqualTo(0);
assertThat(previousPage.getSize()).isEqualTo(0);
}
@Test
public void getNextPage_returnsNextPage_whenItIsAFirstPage() throws Exception {
final Page page = new Page(0, 5);
final Page nextPage = page.getNextPage();
assertThat(nextPage).isNotNull();
assertThat(nextPage.getStart()).isEqualTo(5);
assertThat(nextPage.getSize()).isEqualTo(5);
}
@Test
public void getPreviousPage_returnsFullPreviousPage_whenThereAreEnoughSize() throws Exception {
final Page page = new Page(5, 5);
final Page previousPage = page.getPreviousPage();
assertThat(previousPage).isNotNull();
assertThat(previousPage.getStart()).isEqualTo(0);
assertThat(previousPage.getSize()).isEqualTo(5);
}