Overview

AutoParams is an arbitrary test data generator designed for parameterized tests in Java, drawing inspiration from AutoFixture.

Manually configuring test data can be cumbersome, especially when certain data is necessary but not critical to a specific test. AutoParams eliminates this hassle by automatically generating test arguments for your parameterized methods, allowing you to focus more on your domain-specific requirements.

Using AutoParams is straightforward. Simply annotate your parameterized test method with the @AutoSource annotation, in the same way you would use the @ValueSource or @CsvSource annotations. Once this is done, AutoParams takes care of generating appropriate test arguments automatically.

Java

@ParameterizedTest
@AutoSource
void parameterizedTest(int a, int b) {
    Calculator sut = new Calculator();
    int actual = sut.add(a, b);
    assertEquals(a + b, actual);
}

Kotlin

@ParameterizedTest
@AutoSource
fun parameterizedTest(a: Int, b: Int) {
    val sut = Calculator()
    val actual: Int = sut.add(a, b)
    assertEquals(a + b, actual)
}

Java

@ParameterizedTest
@AutoSource
void parameterizedTest(int a, int b) {
    Calculator sut = new Calculator();
    int actual = sut.add(a, b);
    assertEquals(a + b, actual);
}

Kotlin

@ParameterizedTest
@AutoSource
fun parameterizedTest(a: Int, b: Int) {
    val sut = Calculator()
    val actual: Int = sut.add(a, b)
    assertEquals(a + b, actual)
}

In the example above, the automatic generation of test data by AutoParams can potentially eliminate the need for triangulation in tests, streamlining the testing process.

AutoParams also simplifies the writing of test setup code. For instance, if you need to generate multiple review entities for a single product, you can effortlessly accomplish this using the @Freeze annotation.

Java

@AllArgsConstructor
@Getter
public class Product {
    private final UUID id;
    private final String name;
    private final BigDecimal priceAmount;
}

Kotlin

class Product (val id: UUID, val name: String, val priceAmount: BigDecimal)

Java

@AllArgsConstructor
@Getter
public class Review {
    private final UUID id;
    private final Product product;
    private final String comment;
}

Kotlin

class Review(val id: UUID, val product: Product, val comment: String)

Java

@ParameterizedTest
@AutoSource
void testMethod(@Freeze Product product, Review[] reviews) {
    for (Review review : reviews) {
        assertSame(product, review.getProduct());
    }
}

Kotlin

@ParameterizedTest
@AutoSource
fun testMethod(@Freeze product: Product, reviews: Array<Review>) {
    for (review in reviews) {
        assertSame(product, review.product)
    }
}

That's cool!