check50_junit

This is an extension for the CS50 automarker check50 for compiling and running Junit5 unit tests and raising the resulting failures directly as check50 Failures to be used in checks.

This module ships with Junit5's stand-alone console launcher.

Your problem set only needs to include the compiled bytecode of junit test classes, which are compiled against your model solution to the exercise. This gets around the issue that unit tests may not compile for student's code due to unexpected method signatures class identifiers. Such errors will be reflected in the JUnit's report XML file.

Example Usage

TLDR: import check50_junit; add your compiled junit test classes to your pset, and use check50_junit5.run_and_interpret_test within your checks. A full example follows.

All examples below assume that you're importing check50 and check50_junit.

1. Write your model solution and unit test classes and manually compile them.

   public class Drink {
       private final int volume;
   
       public Drink(int v) {
           volume = v;
       }
   
       int getVolume() {
           return volume;
       }

   import static org.junit.jupiter.api.Assertions.*;
   import org.junit.jupiter.api.Test;
   
   class DrinkTest {
     @Test
     public void getVolume() {
       Drink d = new Drink(200);
       assertEquals(200, d.getVolume());
     }
   }

2. Move the bytecode DrinkTest.class somewhere into your pset directory, say under tests/.

3. Add a check as follows (I would usually have this depend on class exists, compiles, and can be instantiated checks).

   @check50.check()
   def drink_getVolume():
       """Test Drink.getVolume()"""
       check50_junit.run_and_interpret_test(
           classpaths=['tests/'],
           args=['--select-method', 'DrinkTest#getVolume'])

   This will run the precompiled unit test on the student submission, parse junit's XML report and raise any check50.Failures as appropriate for the result. In this case it would raise a check50.Mismatch exception if the assertEquals within the unit test is thrown.

4. Make sure to add check50-java as a dependency in your pset's .cs50.yml:

   check50:
     dependencies:
       - check50-java
     files:
       - !exclude "*"
       - !include "*.java"