Getting Started with GrandTestAuto

Writing and running tests with GrandTestAuto (GTA) is very easy. Let's start with an example.

Suppose that you are developing a package pack. The first class to be written is A:


package pack;

public class A {

    public A( String str ) {
        //Constructor body ...
    }

    public String a() {
        //Method body ...
    }

    public String b( String x ) {
        //Method body ...
    }
}

The unit test for this class needs to be in the package pack.test and must be called ATest:


package pack.test;

public class ATest {

    //Class body..

}

We need to have a test method for each of the methods in A and also for the constructor:


package pack.test;

public class ATest {

    public boolean aTest() {
        //Test method body ...
    }

    public boolean bTest() {
        //Test method body ...
    }

    public boolean constructorTest() {
        //Test method body ...
    }
}

In order to get GTA to run this test, we must add a new class to pack.test:


package pack.test;

import org.GrandTestAuto.*;

public class UnitTester extends CoverageUnitTester {
  public UnitTester( GrandTestAuto gta ) {
      super( gta );
  }
}

Before we run the tests, we need to create a settings file that tells GTA where the classes to be tested reside and how we want the test results presented (in a file or just to the console). The following is typical of the contents of this file:


CLASSES_ROOT=E:\\project\\classes

LOG_TO_CONSOLE=true

LOG_TO_FILE=true

If this file is called "Settings.txt", then the command to invoke GTA would be:

java -cp E:\project\classes;gta.jar; org.grandtestauto.GrandTestAuto Settings.txt

Running this would cause some logging statements to be printed to the console and more readable messages printed to a file called "GTAResults.txt" (the name is configurable using the settings file). Assuming that the tests passed, the file output would be something like:


ATest.aTest passed
ATest.bTest passed
ATest.constructorTest passed
>>>> Results of Unit Tests for pack: passed. <<<<
******* Overall Unit Test Result: passed. *******

The points to note so far are:

the test classes are in a sub-package of that being tested
there is a naming pattern for the test classes: "Test" is appended to the name of the class under test
the test classes must have a public no-arguments constructor
the test methods are public, return a boolean, and take no parameters
there is be a class called UnitTester in the test package and it extends grandtestauto.org.CoverageUnitTester
GTA takes its operational parameters from a settings file and the name of this is passed as the single argument to the main method.

Continuing with the example, suppose that we add a new public method c to A. If we run our tests again, the result will be failure and a message that there is an untested method will be printed. Suppose that we add the test for c and create a new class B:


package pack;

public class B extends A {
    public B( String str ) {
        //Constructor body ...
    }

    public String a() {
        //Method body ...
    }

    public String d( String x ) {
        //Method body ...
   }
}

If we invoke GTA at this point, our tests will fail because there is no test class for B. The unit test for B must test precisely the methods of B that are defined in the package of B and are not already tested. That is, we must test the over-ridden version of a and also the new method b. We do not need to test the methods inherited from A (as these are tested in ATest) or those inherited from java.lang.Object (as these are defined in another, presumably well tested, package).

The use of CoverageUnitTester is forcing us to be very thorough about our testing. Points to note are:

we must provide a test method for every accessible method in a public class
we must provide a test class for every public class
all the test methods in all the test classes get run automatically by GTA
we do not need to write tests for methods that are tested by other test classes within the same test package
we do not need to write tests for methods that are inherited from outside the package under test.

This is enough information to get started with GTA. In the advanced tutorial we will see that protected methods must and can be tested, how to test multiple methods with the same name, and more on inherited methods.