JUnit 6.0.1 · org.junit.jupiter.api.extension.TestInstanceFactory

TestInstanceFactory defines the API for Extensions that wish to create test instances.

Common use cases include creating test instances with special construction requirements or acquiring the test instance from a dependency injection framework.

Extensions that implement TestInstanceFactory must be registered at the class level.

Warning

Only one TestInstanceFactory is allowed to be registered for any given test class. Registering multiple factories for any single test class will result in an exception being thrown for all tests in that class, in any subclass, and in any nested class. Note that any TestInstanceFactory registered in a superclass or enclosing class (i.e., in the case of a @Nested test class) is inherited. It is therefore the user's responsibility to ensure that only a single TestInstanceFactory is registered for any specific test class.

Constructor Requirements

Consult the documentation in Extension for details on constructor requirements.

`ExtensionContext` Scope

As of JUnit Jupiter 5.12, this API participates in the TestInstantiationAwareExtension contract. Implementations of this API may therefore choose to override getTestInstantiationExtensionContextScope(ExtensionContext) to require a test-method scoped ExtensionContext. See createTestInstance(TestInstanceFactoryContext, ExtensionContext) for further details.

Method Summary

Modifier and Type	Method and Description
public Object	Returns: the test instance; never `null` createTestInstance(TestInstanceFactoryContext the context for the test class to be instantiated; never `null` factoryContext, ExtensionContext the current extension context; never `null` extensionContext) Callback for creating a test instance for the supplied context.

Inherited from org.junit.jupiter.api.extension.TestInstantiationAwareExtension:: getTestInstantiationExtensionContextScope

Method Detail

createTestInstance back to summary

createTestInstance	back to summary
public Object createTestInstance(TestInstanceFactoryContext factoryContext, ExtensionContext extensionContext) throws TestInstantiationException Callback for creating a test instance for the supplied context. By default, the supplied `ExtensionContext` represents the test class that's about to be instantiated. Extensions may override `getTestInstantiationExtensionContextScope` to return `TEST_METHOD` in order to change the scope of the `ExtensionContext` to the test method, unless the `PER_CLASS` lifecycle is used. Changing the scope makes test-specific data available to the implementation of this method and allows keeping state on the test level by using the provided `Store` instance. Note the `ExtensionContext` supplied to a `TestInstanceFactory` will always return an empty `java.util.Optional` value from `getTestInstance()` since the test instance cannot exist before it has been created by a `TestInstanceFactory` or the framework itself. Parameters factoryContext:TestInstanceFactoryContext the context for the test class to be instantiated; never `null` extensionContext:ExtensionContext the current extension context; never `null` Returns:Object the test instance; never `null` Exceptions TestInstantiationException: if an error occurs while creating the test instance

public Object createTestInstance(TestInstanceFactoryContext factoryContext, ExtensionContext extensionContext) throws TestInstantiationException

Callback for creating a test instance for the supplied context.

By default, the supplied ExtensionContext represents the test class that's about to be instantiated. Extensions may override getTestInstantiationExtensionContextScope to return TEST_METHOD in order to change the scope of the ExtensionContext to the test method, unless the PER_CLASS lifecycle is used. Changing the scope makes test-specific data available to the implementation of this method and allows keeping state on the test level by using the provided Store instance.

Note

the ExtensionContext supplied to a TestInstanceFactory will always return an empty java.util.Optional value from getTestInstance() since the test instance cannot exist before it has been created by a TestInstanceFactory or the framework itself.

Parameters

factoryContext:TestInstanceFactoryContext: the context for the test class to be instantiated; never null
extensionContext:ExtensionContext: the current extension context; never null

Returns:Object

the test instance; never null

Exceptions

TestInstantiationException:: if an error occurs while creating the test instance

public Interface TestInstanceFactory

Warning

Constructor Requirements

ExtensionContext Scope

Method Summary

Method Detail

`ExtensionContext` Scope