README.md

java-autotests

The repo shows how to automate tests for Java classes, run them on GitHub Actions, and present CodeCoverage.

The idea is to use reflection and, based on extracted fields and their types, dynamically construct and invoke getters and setters.

// tester class
class AutoTests {
  
    private static final Class[] classToTest = new Class[]{ 
        // the list of classes to test
        PersonClass.class, AnimalClass.class
    };

   @Test 
   public void correctGettersSetters() {
      for (Class aClass : classToTest) {
        Object instance;
        try {      
           instance = aClass.getDeclaredConstructor().newInstance();
           Field[] declaredFields = aClass.getDeclaredFields();
           for(Field f: declaredFields) {
              // get the field getter and setter, following the Java naming convention (!)
              // www.theserverside.com/feature/Java-naming-conventions-explained
              String name = f.getName();
              name = name.substring(0,1).toUpperCase() + name.substring(1);
              String getterName = "get" + name;
              String setterName = "set" + name;
              Method getterMethod = aClass.getMethod(getterName);
              Method setterMethod = aClass.getMethod(setterName, getterMethod.getReturnType());
              // prepare a test value based on the filed type 
              Object testVal = null;
              Class<?> fType = f.getType();
              if (fType.isAssignableFrom(Integer.class)) {
                  testVal = 1234;
              } else if (fType.isAssignableFrom(String.class)) {
                  testVal = "abcd";
              }
              // test by composing the setter and getter
              setterMethod.invoke(instance, testVal);
              Object result = getterMethod.invoke(instance);
              System.out.printf("Testing class=%s field=%s...\n", aClass.getName(), f.getName());
              assertThat(result).as("in class %s fields %s", aClass.getName(), f.getName()).isEqualTo(testVal);
           }
        } catch(Exception e) {
           System.out.println(e.toString());
        }
      }
   }
}