JUnit 5 aims to adapt java 8 style of coding and to be more robust and flexible than JUnit 4. In this post, JUnit 5 vs JUnit 4, we will focus on some major differences between them.
Basic Annotations
Most of annotations in both versions are same, but few differs. Here is a quick comparison.
| Feature | JUnit 4 | Junit 5 |
|---|---|---|
| Declare a test method | @Test | @Test |
| Execute before all test methods in the current class | @BeforeClass | @BeforeAll |
| Execute after all test methods in the current class | @AfterClass | @AfterAll |
| Execute before each test method | @Before | @BeforeEach |
| Execute after each test method | @After | @AfterEach |
| Disable a test method / class | @Ignore | @Disabled |
| Test factory for dynamic tests | NA | @TestFactory |
| Nested tests | NA | @Nested |
| Tagging and filtering | @Category | @Tag |
| Register custom extensions | NA | @ExtendWith |
Other differences JUnit 5 vs JUnit 4
| JUnit 4 | JUnit 5 | |
|---|---|---|
| Architecture | It has everything bundled into single jar file. | It is composed of 3 sub-projects i.e. JUnit Platform, JUnit Jupiter and JUnit Vintage.
|
| Required JDK Version | Java 5 or higher | Java 8 or higher |
| Assertions | org.junit.Assert has all assert methods to validate expected and resulted outcomes. They accept extra parameter for error message as FIRST argument in method signature. e.g. public static void assertEquals(long expected, long actual) public static void assertEquals(String message, long expected, long actual) | org.junit.jupiter.Assertions contains most of assert methods including additional assertThrows() and assertAll() methods. assertAll() is in experimental state as of today, and is used for grouped assertions.JUnit 5 assertions methods also have overloaded methods to support passing error message to be printed in case test fails e.g. public static void assertEquals(long expected, long actual) public static void assertEquals(long expected, long actual, String message) public static void assertEquals(long expected, long actual, Supplier messageSupplier) |
| Assumptions | org.junit.Assume contains methods for stating assumptions about the conditions in which a test is meaningful. It has following five methods:
| org.junit.jupiter.api.Assumptions contains methods for stating assumptions about the conditions in which a test is meaningful. It has following three methods:
All assume methods have many overloaded forms to deal with varying requirements. |
| Tagging and Filtering | @category annotation | @tag annotation |
| Test Suites | @RunWith and @Suite annotation. e.g.
import org.junit.runner.RunWith;
import org.junit.runners.Suite;
@RunWith(Suite.class)
@Suite.SuiteClasses({
ExceptionTest.class,
TimeoutTest.class
})
public class JUnit4Example
{
}
| @RunWith, @SelectPackages and @SelectClasses e.g.
import org.junit.platform.runner.JUnitPlatform;
import org.junit.platform.suite.api.SelectPackages;
import org.junit.runner.RunWith;
@RunWith(JUnitPlatform.class)
@SelectPackages("com.howtodoinjava.junit5.examples")
public class JUnit5Example
{
}
|
| 3rd Party Integration | No integration support for 3rd party plugins and IDEs. They have to rely on reflection. | JUnit 5 has dedicated sub-project for this purpose i.e. JUnit Platform. It defines the TestEngine API for developing a testing framework that runs on the platform. |
Drop me your thoughts about this comparison between junit 5 and junit 4 in comments section.
Happy Learning !!
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