Adding Bean Validation

Sometimes, you might want to create a valid test object that adheres to the constraints specified by the Bean Validation annotations on your class. Fixture Monkey makes this easy with support for jakarta.validation.constraints and javax.validation.constraints packages.

For example, consider a Product class with validation constraints:

@Value
public class Product {
    @Min(1)
    long id;

    @NotBlank
    String productName;

    @Max(100000)
    long price;

    @Size(min = 3)
    List<@NotBlank String> options;

    @Past
    Instant createdAt;
}

To generate objects that satisfy these constraints, first add the appropriate dependency:

Gradle #

testImplementation("com.navercorp.fixturemonkey:fixture-monkey-jakarta-validation:1.1.11")

Maven #

<dependency>
  <groupId>com.navercorp.fixturemonkey</groupId>
  <artifactId>fixture-monkey-jakarta-validation</artifactId>
  <version>1.1.11</version>
  <scope>test</scope>
</dependency>

Then, add the validation plugin to your FixtureMonkey configuration:

FixtureMonkey fixtureMonkey = FixtureMonkey.builder()
    .plugin(new JakartaValidationPlugin()) // or new JavaxValidationPlugin()
    .build();

Note: If you’re using fixture-monkey-starter, the validation plugin is already included.

Now you can generate valid objects that satisfy all constraints:

@Test
void test() {
    // given
    FixtureMonkey fixtureMonkey = FixtureMonkey.builder()
        .objectIntrospector(ConstructorPropertiesArbitraryIntrospector.INSTANCE)
        .plugin(new JakartaValidationPlugin())
        .build();

    // when
    Product actual = fixtureMonkey.giveMeOne(Product.class);

    // then
    then(actual).isNotNull();
    then(actual.getId()).isGreaterThan(0);
    then(actual.getProductName()).isNotBlank();
    then(actual.getPrice()).isLessThanOrEqualTo(100000);
    then(actual.getOptions().size()).isGreaterThanOrEqualTo(3);
    then(actual.getOptions()).allSatisfy(it -> then(it).isNotEmpty());
    then(actual.getCreatedAt()).isNotNull().isLessThanOrEqualTo(Instant.now());
}

When you run this code, Fixture Monkey will generate a Product instance that satisfies all validation constraints. Below is just an example, and the actual values will be different each time:

Product(
    id=42,                   // Satisfies @Min(1)
    productName="product-1", // Satisfies @NotBlank
    price=75000,            // Satisfies @Max(100000)
    options=[               // Satisfies @Size(min = 3)
        "option1",          // Each string satisfies @NotBlank
        "option2",
        "option3"
    ],
    createdAt=2024-03-20T10:15:30Z  // Satisfies @Past
)