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JUnit passing parameters between class

I have a scenario as follows that I'm not sure from where to start,
File name should be passed as an argument param when running the jar file
say for example I want to test a set of data from external file and I have a super class (Test Suite) that have number one and number two
and there are two test classes that should extend this class and perform the tests.
I'm currently new to JUnit so I'm lacking many concepts and need someone's help.
I have class CoreManager which executes the main
public static void main(String[] args)
{
if (Arrays.asList(args).contains("Import"))
{
accountInfo = new ArrayList<>();
int ImportIndex = Arrays.asList(args).indexOf("Import");
String fileName = args[ImportIndex+1];
if (fileName.contains("xml"))
{
ParseXML parseXML = new ParseXML();
accountInfo = parseXML.ParseAccounts(fileName);
Result result = JUnitCore.runClasses(LoginTestSuite.class);
for (Failure failure : result.getFailures()) {
System.out.println(failure.toString());
}
System.out.println(result.wasSuccessful());
}
}
}
And Suite Class
#RunWith(MockitoJUnitRunner.class)
#Suite.SuiteClasses({
Login.class,
SignUp.class
})
public class LoginTestSuite {
public static WebDriver driver;
public static ArrayList<AccountInfo> Account;
public static int SecondsToWait;
public LoginTestSuite(WebDriver driver,ArrayList<AccountInfo> Account,int
secondsToWait)
{
this.Account = Account;
this.SecondsToWait = secondsToWait;
this.driver = driver;
}
}
And Test Class
public class Login {
private static WebDriver driver;
private static ArrayList<AccountInfo> Account;
private static int SecondsToWait;
private static final Logger logger = Logger.getLogger(Login.class.getName());
#BeforeClass
public void init(){
this.driver = LoginTestSuite.driver;
this.Account = LoginTestSuite.Account;
this.SecondsToWait = LoginTestSuite.SecondsToWait;
}
#Before
public void Setup(){
driver.manage().window().maximize();
driver.manage().timeouts().implicitlyWait(SecondsToWait,
TimeUnit.SECONDS);
driver.manage().timeouts().pageLoadTimeout(SecondsToWait,
TimeUnit.SECONDS);
}
#After
public void TearDown(){
driver.quit();
}
#Test
public void TestUserLogin() throws Exception
{
// Logic
}

Your code looks muddled and contains several poor quality constructs. Most importantly, I don't see a distinction between test code and production code. Which is which?
This could be production code:
public class App {
public static void main(String[] args) {
AccountReader accountReader = new AccountReader();
List<AccountInfo> accounts = accountReader.read(args);
// maybe do something with those accounts?
}
}
public class AccountReader {
private ParseXML parseXML;
public AccountReader() {
this.parseXML = new ParseXML();
}
// extra constructor to allow dependency injection from test
protected AccountReader(ParseXML parseXML) {
this.parseXML = parseXML;
}
public List<AccountInfo> read(String[] args) {
return parseXML.ParseAccounts(getFileName(args));
}
private String getFileName(String[] args) {
List<String> arguments = Arrays.asList(args);
int importIndex = arguments.indexOf("Import");
if (importIndex < 0) {
throw new RuntimeException("Missing Import argument");
}
int fileNameIndex = importIndex + 1;
if (fileNameIndex >= arguments.size()) {
throw new RuntimeException("Missing fileName argument");
}
String fileName = args[fileNameIndex];
if (!fileName.endsWith(".xml")) {
throw new RuntimeException("Can only import XML files");
}
return fileName;
}
}
And this could be a test for it:
public AccountReaderTest {
private AccountReader instance;
#Mock // creates a mock instance which we can give desired behavior
private ParseXML parseXML;
#Mock
List<AccountInfo> accounts;
#Before
public void setUp() {
instance = new AccountReader(parseXML);
}
#Test
public void testHappy() {
// SETUP
String fileName = "test.xml";
// specify desired behavior of mock ParseXML instance
when(parseXML.ParseAccounts(fileName).thenReturn(accounts);
// CALL
List<AccountInfo> result = instance.read(new String[] { "Import", fileName });
// VERIFY
assertEquals(accounts, result);
}
#Test(expected = RuntimeException.class)
public void testMissingImport() {
instance.read(new String[] { "notImport" });
}
#Test(expected = RuntimeException.class)
public void testMissingFileName() {
instance.read(new String[] { "Import" });
}
#Test(expected = RuntimeException.class)
public void testNotXml() {
instance.read(new String[] { "Import", "test.properties"});
}
}

How to cache a JUnit class field between runs with #Parameters

Lets assume the following JUnit test class:
#RunWith(Parameterized.class)
public class MyTestClass {
private ExpensiveObjectToCreate myObject;
#Parameters
public static Collection<Object[]> data() {
Object[][] data = new Object[][] {
{ "parameter1" },
{ "parameter2" },
};
return Arrays.asList(data);
}
#Test
public void test1() {
}
#Test
public void test2() {
}
public MyTestClass(String stringParameter) {
myObject = new ExpensiveObjectToCreate(stringParameter);
}
}
Is there any way for me to create the expensive object just once for every parameter set? I say this because JUnit creates a new test class for every test it needs to run. This means that the expensive object is NOT created 2 times, but actually 4 times (2 parameter sets x 2 tests). This gets even worse when we have many test methods.
Also, sending the expensive object as a parameter is not a solution for me because my scenario is a little bit more complicated (I create the expensive object in JUnit rules).

Why not just roll out a custom cacher in your test case class, which caches the instance created per parameter and returns the same instance on further invocations.
#RunWith(Parameterized.class)
public class Test {
private static ExpensiveObjectCacher cacher; //instance which caches parameter instance
private ExpensiveObject myObject;
public Test(String value) {
this.myObject = cacher.get(value);
}
#BeforeClass
public static void setUpBeforeClass(){
cacher = new ExpensiveObjectCacher();
}
#Parameters
public static Collection<Object[]> data() {
Object[][] data = new Object[][] {
{ "parameter1" },
{ "parameter2" },
};
return Arrays.asList(data);
}
#org.junit.Test
public void test1(){
}
#org.junit.Test
public void test2(){
}
}
//caching for test cases.
class ExpensiveObjectCacher{
private Map<String, ExpensiveObject> map = new ConcurrentHashMap<String, ExpensiveObject>();
ExpensiveObject get(String value){
ExpensiveObject instance = map.get(value);
if(instance == null){
instance = new ExpensiveObject(value);
map.put(value, instance);
}
return instance;
}
}
class ExpensiveObject{
public ExpensiveObject(String value) {
System.out.println("Instance created: " + value);
}
}
Output:
Instance created: parameter1
Instance created: parameter2

You could work with a static Map from the parameters (here a simple string) to instances of ExpensiveObjectToCreate.
#RunWith(Parameterized.class)
public fnial class MyTestClass {
private static final Map<Parameter, ExpensiveObjectToCreate> MAPPING = new HashMap<>();
private ExpensiveObjectToCreate myEOTC;
public MyTestClass(String stringParameter) {
myEOTC = getEOTC(new Parameter(stringParameter));
}
private static getEOTC(Parameter parameter) {
ExpensiveObjectToCreate eotc = MAPPING.get(parameter);
if (eotc == null) {
eotc = new ExpensiveObjectToCreate(parameter.stringParameter);
MAPPING.put(parameter, eotc);
}
rturn eotc;
}
private static final class Parameter {
String stringParameter;
Parameter(String stringParameter) { this.stringParameter = stringParameter; }
#Override public int hashCode() { ... }
#Override public boolean equals(Object other) { ... }
}
}
However, if you also need to limit the number of expensive objects, you should do more work, for example a cache could be a solution.

If you're using Junit 4:
private static ExpensiveObjectToCreate myObject;
private static String stringParameter = "some text";
#BeforeClass
public static void setUpBeforeClass() throws Exception {
myObject = new ExpensiveObjectToCreate(stringParameter);
}
If Junit 3:
private static ExpensiveObjectToCreate myObject;
private static String stringParameter = "some text";
#BeforeClass
protected static void setUpBeforeClass() throws Exception {
myObject = new ExpensiveObjectToCreate(stringParameter);
}
In both cases the object will be created once for all the unit tests.
Edit: The String I am not sure where it came from, so I am asuming that the String is the same for all unit tests.

Use old instance in JUnit test

I try to use different instances for my tests but the first one is always used.
During the second test, it's the content of the first instance that is displayed.
I don't know where to look for.
public class MyActivityTest extends
ActivityInstrumentationTestCase2<MyActivity> {
private Solo solo;
public MyActivityTest() {
super(MyActivity.class);
}
protected void setUp() throws Exception {
super.setUp();
Authentication.setSessionId("mysessionid", this.getInstrumentation()
.getTargetContext().getApplicationContext());
solo = new Solo(getInstrumentation(), getActivity());
}
public void testFailFetching() {
CommunicationFactory.setInstance(MyActivityData.FALSE_QUIZCOMM_DEFAULT);
//some Solo tests
}
public void testSucceedFetching() {
CommunicationFactory.setInstance(MyActivity.CORRECT_QUIZCOMM_DEFAULT);
//some Solo tests
}
#Override
protected void tearDown() throws Exception {
CommunicationFactory.setInstance(null);
super.tearDown();
}
}

The setUp() method will be called before each test. Provided it completes without throwing an exception (which presumably would abort your tests anyway), your solo variable is being reconstructed for each test. The follow test code demonstrates this:
public class ExampleTest extends TestCase {
private static int num = 1;
private Foo foo;
#Override
protected void setUp() throws Exception {
super.setUp();
foo = new Foo(num++);
}
public void testA() {
foo.printNum();
}
public void testB() {
foo.printNum();
}
private static class Foo {
private final int num;
public Foo(int num) {
this.num = num;
}
public void printNum() {
System.out.println(num);
}
}
}
This prints:
1
2
It's possible the Solo objects equal each other in the separate tests. But they won't be the same object.

Setting up a test system with "real data"

So right now I'm using JUnit 4 and in the #BeforeClass methods I setup everything needed to reset the user schema or to prepare sample data.
Now, it's not that I don't like this approach but I found it quite frustrating for the following reason:
I'm using the Parameterized annotation to run the very same tests with different input data. Parameterized doesn't work on #BeforeClass because #BeforeClass works with a static method.
This means I have to replicate tests if I want to keep the #BeforeClass logic. I can't use #After and #Before because those will happen after every test and it would be an overhead.
I was thinking I could refactor this Unit Tests in the sense that I'll write an abstract class that handles the test and a subclass for every group parameters I want to try so that I can have the test code written only once.
I'm hoping you can suggest a cleaner option with the following starting point: the use of #Parameterized, the need to run the "database" method only once per parameter group.
EDIT:
this is an example of my class without the BeforeClass
RunWith(LabelledParameterized.class)
public class TestCreateCampaign extends AbstractTestSubscriberCampaign {
public TestCreateCampaign(String label, String apiKey, String userKey,
int customerId) {
super(label, apiKey, userKey, customerId);
}
#Before
public void setUp() throws Exception {
super.setUp();
}
#After
public void tearDown() throws Exception {
super.tearDown();
}
#Parameters
public static Collection<Object[]> generatedData() {
return DataProvider.generatedCorrectSubscriberData();
}
#Test
public void testCreateEmailCampaignBothTriggered() {
// TEST
}
#Test
public void testCreateTextCampaignTriggered() {
// TEST
}
#Test
public void testCreateTextCampaignTest() {
// TEST
}
// Other Tests
}

This depends on how you want to set up your classes, but you can use a ClassRule for this. This does the same job as a TestRule, but it runs once for each class, rather than each test. This can be combined with Parameterized and TestRule, such as:
#RunWith(Parameterized.class)
public class TestCreateCampaign {
#ClassRule
public static ExternalResource beforeAfterClass = new ExternalResource() {
#Override
protected void before() throws Throwable {
System.out.println("before each class");
}
#Override
protected void after() {
System.out.println("after each class");
}
};
#Rule
public ExternalResource beforeAfter = new ExternalResource() {
#Override
protected void before() throws Throwable {
System.out.println("before each test");
}
#Override
protected void after() {
System.out.println("after each test");
}
};
#Parameters(name = "{index}: fib({0})={1}")
public static Iterable<Object[]> data() {
return Arrays.asList(new Object[][] { { 3, 0 }, { 4, 1 } });
}
private int fInput;
private int fExpected;
public TestCreateCampaign(int input, int expected) {
fInput = input;
fExpected = expected;
}
#Test
public void test1() {
System.out.println("test1 fInput=" + fInput);
}
}
This produces the following output:
before each class
before each test
test1 3
after each test
before each test
test1 4
after each test
after each class
This seems to be what you're looking for. To cut down on the amount of duplication, you can of course define beforeAfterClass and beforeAfter in a separate java class.
These are available in JUnit 4.9+.

What about calling your setup method from the constructor of your parameterized test class?
Edit:
OK, do I don't know of anything that does this automatically, but I think you could code up a Rule to do it. You could either implement a Rule from scratch of extend ExternalResource. Here is what I think it would do.
The constructor would take an instance of the test class and an ExternalResource instance.
In the constructor it would find the list of methods that contain the #Test annotation a get a count. It would set an iteration count to 0.
In the before method it would increment the iteration count and if it is 1 after increment (or 0 before) it would invoke the before method on the passed ExternalResource.
In the after method it would check to see if the iteration count was equal to the number of tests and if so call the after method on the passed ExternalResource.
You might need to use a different callback class / interface and ExternalResource since the before and after methods are protected. If you really wanted to be cool, you would define your own BeforeParameters and AfterParameter annotations in your rule and it would look for those methods in the passed instance.
If you develop this please post it or submit it to JUnit for inclusion.
Here is what I came up with, not as nice as I would like:
#RunWith(Parameterized.class)
public class TestExample {
private interface BeforeAfter {
void before();
void after();
}
public static class Resource extends ExternalResource {
private final int count;
private final BeforeAfter ba;
private int iteration = 0;
Resource(Object instance, BeforeAfter ba) {
int localCount = 0;
for (Method method : instance.getClass().getMethods()) {
if (method.getAnnotation(Test.class) != null) {
localCount++;
}
}
this.count = localCount;
this.ba = ba;
}
#Override
protected void before() throws Throwable {
if (iteration == 0) {
ba.before();
}
iteration++;
}
#Override
protected void after() {
if (iteration == count) {
ba.after();
iteration = 0;
}
}
}
#Parameters
public static Iterable<Object[]> data() {
return Arrays.asList(new Object[][] { { 3, 0 }, { 4, 1 } });
}
#Rule
public static Resource resource = new Resource(new TestExample(0, 0), new BeforeAfter() {
#Override
public void before() {
System.out.println("setup");
}
#Override
public void after() {
System.out.println("cleanup");
}
});
private int fInput;
private int fExpected;
public TestExample(int input, int expected) {
// System.out.println("Constructor invoked" + fInput);
fInput = input;
fExpected = expected;
}
#Test
public void test1() {
System.out.println("test1 fInput=" + fInput);
}
#Test
public void test2() {
System.out.println("test2 fInput=" + fInput);
}
}
Resulted in:
setup
test1 fInput=3
test2 fInput=3
cleanup
setup
test1 fInput=4
test2 fInput=4
cleanup

See How to load DBUnit test data once per case with Spring Test for a way of initialising your test data only once per test run.

Running two same tests with different arguments

I have a test with 15-20 different test cases, I want to run the same test with twice with two different parameters which are supposed to be passed to the test's BeforeClass method, for instance:
public class TestOne {
private static ClassToTest classToTest;
#BeforeClass
public static void setUp() throws Exception {
classToTest = new ClassToTest("Argument1", "Argument2");
}
#Test
public void testOne() {
........roughly 15 - 20 tests here
}
public class TestTwo {
private static ClassToTest classToTest;
#BeforeClass
public static void setUp() throws Exception {
classToTest = new ClassToTest("Argument3", "Argument4");
}
#Test
public void testOne() {
........roughly 15 - 20 tests here, same as in TestOne
}
As you can see the only difference between these two tests is in the setup method, which passes different values to the constructor of the ClassToTest. I don't want to replicate the test methods in both classes, but would prefer either inheritance or some other intelligent way to achieve this in one class.

This seems like a perfect use case for JUnit4's #Parameters; see https://blogs.oracle.com/jacobc/entry/parameterized_unit_tests_with_junit or http://www.mkyong.com/unittest/junit-4-tutorial-6-parameterized-test/ . That said, you'll have to move the initialization from the setUp method to a constructor for the test class.

For what it's worth, here is how you would do it with TestNG:
public class TestFactory {
#Factory
public Object[] createTests() {
return new Object[] {
new ClassToTest("arg1", "arg2"),
new ClassToTest("arg3", "arg4")
};
}
}
public class ClassToTest {
public ClassToTest(String arg1, String arg2) {
this.arg1 = arg1;
this.arg2 = arg2;
}
#Test
public void testOne() {
// use arg1 and arg2
}
}

Thanks all for your quick replies. This is how I did it finally
public abstract class Base {
final HeavyObject heavy;
protected Base(HeavyObject heavy) {
this.param = param;
}
#Test
public void test() {
param.doSomething();
}
#Test
.............More tests here
}
public class FirstTest extends Base{
private static HeavyObject param;
#BeforeClass
public static void init() {
param = new HeavyObject("arg1", "arg2");
}
public FirstTest() {
super(param);
}
}
public class SecondTest extends Base{
private static HeavyObject param;
#BeforeClass
public static void init() {
param = new HeavyObject("arg3", "arg4");
}
public FirstTest() {
super(param);
}
}
Base is an abstract class which has all the tests and FirstTest and SecondTest create their own objects with different parameters and pass it to the abstract class to use it.

As per the documentation (http://docs.oracle.com/javase/tutorial/java/IandI/subclasses.html):
A subclass does not inherit the private members of its parent class.
However, if the superclass has public or protected methods for
accessing its private fields, these can also be used by the subclass.

How about this:
public class TestOne {
private static ClassToTest classToTest1, classToTest2;
#BeforeClass
public static void setUp() throws Exception {
classToTest1 = new ClassToTest("Argument1", "Argument2");
classToTest2 = new ClassToTest("Argument3", "Argument4");
}
#Test
public void testOne() {
testOneImpl(classToTest1);
testOneImpl(classToTest2);
}
public void testOneImpl(ClassToTest classToTest) {
// exact samew as whatever your current testOne() test method is
}
....
}
EDIT:
Or to keep method count down:
public class TestOne {
private static List<ClassToTest> classesToTest;
#BeforeClass
public static void setUp() throws Exception {
classesToTest = new ArrayList<>;
classesToTest.add( new ClassToTest("Argument1", "Argument2"));
classesToTest.add( new ClassToTest("Argument3", "Argument4"));
}
#Test
public void testOne() {
for (ClassToTest classToTest: classesToTest) {
... same test content as before
}
}