CODEWITHSUNDEEP
javaunit-testingintellij-ideajunit
Hesham
Hesham

Reputation: 13

How do I use JUnit to unit test methods in one Java class, without having completed other classes in the module?

So my issue is that I am working on a Java project in IntelliJ IDEA and in my working directory, I have 12-13 Java class files.

I am working on each Java class, and I would like to use JUnit to test the methods I implement in each class.

I have set up a testClass for one of these classes, however, when I try to run it, I guess Java tries to compile everything in the directory and because the other classes aren't implemented, it doesn't finish compiling.

My question is: What is the best way to do unittests on individual class methods without having to implement every class in my directory?( I come from a python background so is this question even relevant in Java?)

Thanks.

Upvotes: 0

Views: 386

Answers (2)

Mark
Mark

Reputation: 1174

First, welcome to the Java language! May you have as good of a time with Java as you have with Python. Most build systems (Ant, Maven, Gradle, etc) generally compile all source files within a project directory. In order for the compilation phase to complete successfully you need a program which follows the language semantics as well as any symbols referenced (classes, methods, packages, etc) to be resolvable.

While building software in Java your best bet is to leave the files within your project in a sane state. This will allow you to test features as you complete them. I've been in positions while placing code under test where I had to temporarily comment out code which broke until I could fix other pains first.

As @David Wallace pointed out Mockito and JMockit are excellent tools for mock based testing with inter class dependencies.

Upvotes: 0

Dawood ibn Kareem
Dawood ibn Kareem

Reputation: 79818

If your class does not call methods of those other classes in the methods that you're testing, then it shouldn't be an issue if the compiler fails to compile those other classes. Provided the class that you're testing compiles, you should be able to run anything in it.

However, if your class does call methods in some other class that doesn't exist yet, then you probably want to just to put "empty" versions of all the methods that you want to call into the required classes. This will enable you to compile the class that you wish to test.

If you want the methods that you're calling to have specific behaviour within your unit test, in order to test some condition that can arise when you call those methods, then you should look into using a "mocking framework". I can happily recommend either JMockit or Mockito (although I have to admit to being loosely affiliated with the Mockito development team).

Upvotes: 3

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