[FIXED] Running only the tests with @MyTest inside java application

Issue

I have a TestRunner class:

public class TestRunner {

    private String result = "";

    public void runTests(List<String> testClassNames) {
        for (String testClassName : testClassNames) {

        }
    }

    public String getResult() {
        return result;
    }
}

Then I have two test classes and I should run only the tests with @MyTest from both classes. getResult() should essentialy return "exampleTest() - OK" or "exampleTest() - FAILED", depending on if the test passes. Test class looks like this:

public class ExampleTests1 {

    @MyTest (expected = IllegalStateException.class)
    public void test1() {
        throw new IllegalStateException();
    }

    @MyTest (expected = IllegalStateException.class)
    public void test2() {
        throw new RuntimeException();
    }
}

I tried to do it with JUnitCore and Result, but couldn't find a way to get the test method name to add to the result. Is there another way?

Solution

You'll have to use reflection in this case. This is kind of how JUnit works internally:

Since this sounds as a homework/assigment for educational purposes (If you're developing a "real" application - then just use JUnit or TestNG and don't write anything like this by yourself :) ), I won't provide a full solution however this is what you should do:

1. For each class identified by a className you should get a java.lang.Class that describes this class name. You can use Class.forName(...)
2. Then you should get all the methods of that class (by reflection) and for each method run the following:

2.1 Check whether the method is marked with an annotation @MyTest. If it doesn't - don't handle it

2.2 Also check whether the method name starts with test (String has startsWith method)

2.3 If you found out that the test class contains test methods, then:

2.3.1 Create an instance of the Test Class (probably you can assume that it has no-ops constructor, then use newInstance())

2.3.2 Run the method (again by reflection). Check the result / surround the execution call with try/catch block to intercept errors.

2.3.3 Print the Result as specified in the assignment :)

Answered By - Mark Bramnik
Answer Checked By - Pedro (JavaFixing Volunteer)