InstanceOf Factories

InstanceOf Factories

ValidationInstanceOfAssertFactories holds AssertJ InstanceOfAssertFactory values for the Jakarta Validation types, for asInstanceOf(…) and for the factory-taking navigation methods of AssertJ (singleElement(…), first(…), element(int, …), extracting(…, factory)) and of this library.

As in AssertJ's own InstanceOfAssertFactories, the non-generic types are constants and the generic ones are methods.

Methods (generic types)

Factory	For	Produces
constraintViolation()	ConstraintViolation<T>	AbstractConstraintViolationAssert<?, ConstraintViolation<T>, T>
constraintDescriptor()	ConstraintDescriptor<T>	AbstractConstraintDescriptorAssert<?, ?, T>

Constants

Group	Constants
exception	CONSTRAINT_VIOLATION_EXCEPTION (not in 0.6.1)
path	PATH
nodes	NODE, BEAN_NODE, PROPERTY_NODE, METHOD_NODE, CONSTRUCTOR_NODE, PARAMETER_NODE, CROSS_PARAMETER_NODE, RETURN_VALUE_NODE, CONTAINER_ELEMENT_NODE
metadata	BEAN_DESCRIPTOR, PROPERTY_DESCRIPTOR, METHOD_DESCRIPTOR, CONSTRUCTOR_DESCRIPTOR, PARAMETER_DESCRIPTOR, RETURN_VALUE_DESCRIPTOR, CROSS_PARAMETER_DESCRIPTOR, CONTAINER_ELEMENT_TYPE_DESCRIPTOR, GROUP_CONVERSION_DESCRIPTOR

Twenty constants in all; a test guards against one being dropped. Each produces the assertion the corresponding ValidationAssertions.assertThat… entry point returns.

Usage

import static com.github.jinahya.assertj.validation.ValidationInstanceOfAssertFactories.*;

// an Object that is known to be a Path
assertThat((Object) violation.getPropertyPath())
        .asInstanceOf(PATH)
        .hasSize(2);

// a node, narrowed to its kind
assertThat((Object) node)
        .asInstanceOf(METHOD_NODE)
        .hasName("greet")
        .extractingParameterTypes().containsExactly(String.class, int.class);

// an element of a plain CollectionAssert
assertThatConstraintViolationException(exception)
        .extractingConstraintViolations()
        .singleElement()
        .asInstanceOf(constraintViolation())
        .hasMessageTemplate("{jakarta.validation.constraints.NotBlank.message}");

assertThatBeanDescriptor(descriptor)
        .extractingConstraintsForProperty("tags")
        .extractingConstrainedContainerElementTypes()
        .singleElement(CONTAINER_ELEMENT_TYPE_DESCRIPTOR)
        .hasContainerClass(List.class);

// an exception reached as a cause
assertThat(thrown)
        .cause()
        .asInstanceOf(CONSTRAINT_VIOLATION_EXCEPTION)
        .hasViolationOn("name");

The node factories check the kind

asInstanceOf first performs an instanceof test, which cannot tell node kinds apart: Hibernate Validator's node implements every Path.Node subtype at once. So each typed node factory — BEAN_NODE through CONTAINER_ELEMENT_NODE — additionally checks Path.Node.getKind() and fails with an AssertionError naming the expected and actual kinds. Without it, asInstanceOf(PROPERTY_NODE) on a method node would succeed, and fail later from inside the provider. NODE accepts any node. See Kind checking.

Assertions that deliberately have none

There is no factory for the assertions which run validation — the bean, property-value and constructor assertions — and none for the set of violations. Those are where a test starts rather than values it meets while navigating, and a factory would have to fix their root bean type. Use the ValidationAssertions entry points for them.