AssertJ

Knižnica AssertJ poskytuje krajšie asserty pre automatické testy. Napríklad:

JUnit	AssertJ
assertTrue(3 < 4);	assertThat(3).isLessThan(4);
assertTrue("abc".contains("a")); assertTrue("abc".contains("b")); assertTrue("abc".contains("c"));	assertThat("abc").contains("a") .contains("b") .contains("c");
assertFalse(list.isEmpty()); assertFalse(list.contains("abc"));	assertThat(list).isNotEmpty() .doesNotContain("abc");

Asserty pre vlastné typy

Máme napríklad takúto triedu:

public record Position(int x, int y) {}

Vytvoríme pre ňu assert:

public class PositionAssert extends AbstractAssert<PositionAssert, Position> {

    protected PositionAssert(Position actual) {
        super(actual, PositionAssert.class);
    }

    public PositionAssert hasX(int expectedX) {
        isNotNull();
        if (actual.x != expectedX) {
            failWithMessage("Expected X %d but was %d", expectedX, actual.x);
        }
        return this;
    }

    public PositionAssert hasY(int expectedY) {
        isNotNull();
        if (actual.y != expectedY) {
            failWithMessage("Expected Y %d but was %d", expectedY, actual.y);
        }
        return this;
    }

}

Pridáme statickú funkciu na elegantné získanie assertu:

public static PositionAssert assertThat(Position position) {
    return new PositionAssert(position);
}

A môžeme písať testy v štýle AssertJ:

@Test
public void testPosition() {
    var p = new Position(3, 4);
    assertThat(p).hasX(3)
                 .hasY(4);
}