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Argument Converter

Understand how to implement custom argument converters in JUnit 5 by using the ArgumentConverter interface and @ConvertWith annotation. Learn to inject complex objects such as user entities into parameterized tests efficiently. This lesson helps you extend JUnit 5 testing capabilities by converting simple input values into meaningful test arguments.

The UserService class

For parameterized tests, JUnit 5 provides built-in converters for some parameter types. We can also create custom converters using the @ConvertWith annotation and the org.junit.jupiter.params.converter.ArgumentConverter interface. The ArgumentConverter interface has only one method, ...