JUnit5 test methods should generally have package visibility. To fix this issue, remove the public or protected visibility modifiers from the test methods.

Why is this an issue?

JUnit5 is more tolerant regarding the visibility of test classes and methods than JUnit4, which required everything to be public. Test classes and methods can have any visibility except private. It is however recommended to use the default package visibility to improve readability.

Test classes, test methods, and lifecycle methods are not required to be public, but they must not be private.

It is generally recommended to omit the public modifier for test classes, test methods, and lifecycle methods unless there is a technical reason for doing so – for example, when a test class is extended by a test class in another package. Another technical reason for making classes and methods public is to simplify testing on the module path when using the Java Module System.

— JUnit5 User Guide

What is the potential impact?

The code will be non-conventional and readability can be slightly affected.

Exceptions

This rule does not raise an issue when the visibility is set to private, because private test methods are systematically ignored by JUnit5, without a proper warning. In this case, there is also an impact on reliability and so it is handled by the rule {rule:java:S5810}.

Note that this rule does not flag the visibility modifier of the test class itself, because there can be legitimate reasons to keep a test class public — for example, when it is referenced in a test suite or extended by a test class in another package.

How to fix it

Remove the public or protected keywords from the test methods.

Code examples

Noncompliant code example

import org.junit.jupiter.api.Test;

class MyClassTest { // Noncompliant - test methods have redundant visibility modifiers
  @Test
  public void test() { // secondary location
    // ...
  }
}

Compliant solution

import org.junit.jupiter.api.Test;

class MyClassTest {
  @Test
  void test() {
    // ...
  }
}

Resources

Documentation