How to keep NUnit tests private in Java projects?

Other Questions API
1

Hey everyone! I’m just starting out with Java and NUnit testing. I’m trying to figure out the best way to test private methods in my classes. Right now, it seems like I have to put the test file in the same package as the class I’m testing. But I don’t want these tests to be part of my public API.

Is there a way to make the test classes or methods only visible within the package? Or do most people just set up a separate build for releasing that doesn’t include the test files?

I’m really curious about the standard practices for this. Any tips or advice would be super helpful! Thanks in advance!

2

As someone who’s been working with Java and NUnit for a while, I can tell you that dealing with private methods in testing can be tricky. One approach I’ve found effective is to use a nested test class within the class you’re testing. This gives the test class access to private members without exposing them externally.

Here’s what I mean:

public class MyClass {
    private void methodToTest() {
        // implementation
    }

    @RunWith(NUnitRunner.class)
    public class TestMyClass {
        @Test
        public void testPrivateMethod() {
            MyClass instance = new MyClass();
            instance.methodToTest();
            // assertions
        }
    }
}

This way, your tests stay with the class they’re testing, but aren’t part of the public API. It’s a clean solution that’s worked well for me in several projects. Just remember to exclude test classes when building for production.

3

hey sarahj, i’ve been there! one trick is using the @VisibleForTesting annotation from guava. it lets u keep methods package-private but still accessable for tests. another option is reflection, but that can get messy. honestly tho, most teams i’ve worked with just put tests in a separate source folder and exclude it from the main build. keeps things clean!