rstraub

data class Weight(val grams: Int)
data class Coffee(val type: Bean, val intensity: Int, val weight: Weight)

fun bugPrevention() = println(
    // Doesn't Compile, integer is not a Weight
    // Coffee(Bean.ARABICA, 1000, 2)
    
    // Also doesn't compile: type mismatch
    // Coffee(Bean.ARABICA, Weight(1000), 2)
    

rstraub

fun doStuff() = print(Coffee(Bean.ARABICA, 1000, 2))

rstraub

enum class Bean {
    ARABICA,
    ROBUSTA,
    BLEND
}

data class Coffee(val type: Bean, val intensity: Int, val weight: Int)

rstraub

@Test
void increased_readability_by_test_data_builder() {
    Invoice invoice =
        anInvoice()
            .from(USA)
            .with(
                aPurchasedBook().of(aNovel().costing(50.0))
            ).build();

    assertEquals(56.35, invoice.computeTotalAmount());

rstraub

@Test
void an_unreadable_test() {
    Country country = new Country("USA", Currency.US_DOLLAR, Language.ENGLISH);
    Author author = new Author("Oscar Wilde", country);
    Novel novel = new Novel(
            "The picture of dorian gray",
            50.00,
            author,
            Language.ENGLISH,
            Lists.newArrayList(Genre.MYSTERY)