Mon

TypeAlias for Java

Maven

<dependency>
    <groupId>net.kemitix</groupId>
    <artifactId>mon</artifactId>
    <version>0.4.0</version>
</dependency>

Usage

TypeAlias

class Goal extends TypeAlias<String> {
    private Goal(final String goal) {
        super(goal);
    }
    public static Goal of(final String goal) {
        return new Goal(goal);
    }
}

Goal goal = Goal.of("goal");

void foo(final Goal goal) {
    System.out.println("The goal is " + goal.getValue());
}

Maybe (Just & Nothing)

assertThat(Maybe.maybe(null)).isEqualTo(Maybe.nothing());
assertThat(Maybe.maybe(1)).isEqualTo(Maybe.just(1));
assertThat(Maybe.nothing()
                .orElseGet(() -> 1)).isEqualTo(1);
assertThat(Maybe.just(1)
                .orElseGet(() -> 2)).isEqualTo(1);
assertThat(Maybe.nothing()
                .orElse(1)).isEqualTo(1);
assertThat(Maybe.just(1)
                .orElse(2)).isEqualTo(1);
assertThat(Maybe.just(1)
                .filter(v -> v > 2)).isEqualTo(Maybe.nothing());
assertThat(Maybe.just(3)
                .filter(v -> v > 2)).isEqualTo(Maybe.just(3));
assertThat(Maybe.just(1)
                .toOptional()).isEqualTo(Optional.of(1));
assertThat(Maybe.nothing()
                .toOptional()).isEqualTo(Optional.empty());
assertThat(Maybe.fromOptional(Optional.of(1))).isEqualTo(Maybe.just(1));
assertThat(Maybe.fromOptional(Optional.empty())).isEqualTo(Maybe.nothing());
final AtomicInteger reference = new AtomicInteger(0);
assertThat(Maybe.just(1).peek(reference::set)).isEqualTo(Maybe.just(1));
assertThat(reference).hasValue(1);
assertThat(Maybe.nothing().peek(v -> reference.incrementAndGet())).isEqualTo(Maybe.nothing());
assertThat(reference).hasValue(1);
assertThatCode(() -> Maybe.just(1).orElseThrow(IllegalStateException::new))
        .doesNotThrowAnyException();
assertThatThrownBy(() -> Maybe.nothing().orElseThrow(IllegalStateException::new))
        .isInstanceOf(IllegalStateException.class);