With JUnit you can use #RunWith(Parameterized.class) to provide a set of parameters to pass to the test constructor and then run tests with each object.
I'm trying to move as much test logic as possible into data, but there are some tests that won't easily be converted into data-driven tests. Is there a way to use JUnit's Parameterized runner to run some tests with parameters, and then also add non-data-driven tests that aren't run repeatedly for each test object construction?
My workaround for this was to create a single class and place the programmatic and data-driven tests in two separate sub-classes. A sub-class must be static for JUnit to run its tests. Here's a skeleton:
#RunWith(Enclosed.class) // needed for working well with Ant
public class MyClassTests {
public static class Programmatic {
#Test
public void myTest(){
// test something here
}
}
#RunWith(Parameterized.class)
public static class DataDriven {
#Parameters
public static Collection<Object[]> getParams() {
return Collections.emptyList();
}
private String data;
public DataDriven(String testName, String data){
this.data = data;
}
#Test
public void test() throws AnalyzeExceptionEN{
// test data string here
}
}
}
one way is to use Junit's Enclosed runner. it's very verbose but also pretty powerful. it allows you to combine multiple different runners in one file.
other option is to use custom junit runner. for sure zohhak supports tests with parameters and without. small extract:
#RunWith(ZohhakRunner.class)
public class CoercingTest {
#TestWith("ONE_OF_ENUM_VALUES")
public void should_coerce_enum(SampleEnum param) {
assertThat(param).isEqualTo(SampleEnum.ONE_OF_ENUM_VALUES);
}
#Test
public void should_run_standard_junit_test() {
//this will also work
}
}
if it's not enough for you, for sure you can find other runners that support both kind of tests.
Related
I have a class, which I use as a basis for my unit tests. In this class I initialize the whole environment for my tests, setting up database mappings, enter a number of database records across multiple tables, etc. That class has a method with a #BeforeClass annotation which does the initialization. Next thing, I extend that class with specific classes in which I have #Test methods.
My question is, since the before class is exactly the same for all these test classes, how can I ensure that they are run only once for all the tests.
One simple solution is that I could keep all the tests in one class. However, the number of tests is huge, also they are categorised based on functional heads. So they are located in different classes. However since they need the exact same setup, they inherit the #BeforeClass. As a result the whole setup is done at least once per test class, taking much more time in total than I would prefer.
I could, though, put them all in various subpackages under one package, hence if there is a way, how I can run set up once for all the tests within that package, it would be great.
With JUnit4 test suite you can do something like this :
#RunWith(Suite.class)
#Suite.SuiteClasses({ Test1IT.class, Test2IT.class })
public class IntegrationTestSuite
{
#BeforeClass
public static void setUp()
{
System.out.println("Runs before all tests in the annotation above.");
}
#AfterClass
public static void tearDown()
{
System.out.println("Runs after all tests in the annotation above.");
}
}
Then you run this class as you would run a normal test class and it will run all of your tests.
JUnit doesn't support this, you will have to use the standard Java work-arounds for singletons: Move the common setup code into a static code block and then call an empty method in this class:
static {
...init code here...
}
public static void init() {} // Empty method to trigger the execution of the block above
Make sure that all tests call init(), for example my putting it into a #BeforeClass method. Or put the static code block into a shared base class.
Alternatively, use a global variable:
private static boolean initialize = true;
public static void init() {
if(!initialize) return;
initialize = false;
...init code here...
}
Create one base class for all tests:
public class BaseTest {
static{
/*** init code here ***/
}
}
and every test should inherit from it:
public class SomeTest extends BaseTest {
}
You can make one BaseTest class with a #BeforeClass method, then have all the other tests inherit from it. This way, when each test object is constructed, #BeforeClass gets executed.
Also avoid executing it just once for all the test suite, since all the test cases should be independent. #BeforeClass should execute only once each test case, not test suite.
If you can tolerate adding spring-test to your project, or you are using it already, then a good approach is to use the technique described here: How to load DBUnit test data once per case with Spring Test
Not sure if anyone still is using JUnit and trying to fix it without using Spring Runner (aka no spring integration). TestNG has this feature. But here is a JUnit based solution.
Create a RunOnce per thread operation like so. This maintains a list of classes for which the operation has run.
public class RunOnceOperation {
private static final ThreadLocal t = new ThreadLocal();
public void run(Function f) {
if (t.get() == null) {
t.set(Arrays.asList(getClass()));
f.apply(0);
} else {
if (!((List) t.get()).contains(getClass())) {
((List) t.get()).add(getClass());
f.apply(0);
}
}
}
}
Back in your unit test
#Before
public beforeTest() {
operation.run(new Function<Integer, Void>() {
#Override
public Void apply(Integer t) {
checkBeanProperties();
return null;
}
});
}
private void checkBeanProperties() {
//I only want to check this once per class.
//Also my bean check needs instance of the class and can't be static.
}
My function interface is like this:
interface Function<I,O> {
O apply(I i);
}
When you use this way, you can perform operations once per class using ThreadLocal.
I have a java package which contains all my test case classes. Each class contains a lot of test cases. Each class is loaded and run one by one by JUnit. However each of the classes contains common configuration code which is run again and again and initialised everytime each of the classes are run.
These initializations take a lot of time.
Is there some way to load these configuration changes first and then run the test case so that I do not need to load them everytime.
JUnit4 has #BeforeClass annotation.
Just do something like this:
public class TestClass {
private static SomeConnection connection;
#BeforeClass
public static void setUp() {
//do common setup
connection = new SomeConnection();
}
#Test
public void testSomething() { }
#Test
public void testSomethingElse() { }
#AfterClass
public static void tearDown() {
//do teardown operations
connection.close();
}
}
Method marked with #BeforeClass will run only once. Just make sure you use JUnit4.
Update:
Also note, that it should be static, and as #ChristopheRoussy mentioned, you can use #AfterClass to destroy your common setup.
You can create a static method that is run before the tests within the class are ran.
#BeforeClass
public static void ranOnlyOnce() {
/*...*/
}
Moreover, if you want to run this once before all of your tests, then you should group your tests in a suite, and put this method in this class, and use JUnit to run the suite instead of the tests.
#RunWith(Suite.class)
#SuiteClasses(value = { Test1.class, ... , Testn.class })
public class AllTests {
#BeforeClass
public static void beforeAllTests() {
/*...*/
}
}
Note that annotations can be used only in Junit 4+.
I would recommend grouping your tests into a testsuite and doing the initialization from the testsuite. There is a good discussion of the possibilities here http://www.xoriant.com/blog/software-testing-and-qa/using-customized-junit-testsuite-for-testing.html
There are a number of possibilities. The first and easiest is to use #BeforeClass and #AfterClass as has been suggested by Matyas and jFrenetic. This is the easiest way to do it if none of the test classes share setup code.
If the classes share the same setup and teardown, look at using the TestRule, specifically the ExternalResource, which allows you to run code before and after each class. The difference between this and #BeforeClass and #AfterClass is that it uses the same class, and therefore the code can be shared more easily. This can be done for example:
#RunWith(Suite.class)
#SuiteClasses({A.class, B.class, C.class})
public class UsesExternalResource {
public static Server myServer= new Server();
#ClassRule
public static ExternalResource resource= new ExternalResource() {
#Override
protected void before() throws Throwable {
myServer.connect();
};
#Override
protected void after() {
myServer.disconnect();
};
};
}
This works in a test class as well, so you could have different, but shared setups for different classes.
I am writting jnuit test case for testing API.
my class is as follows
class MyTest extends TestCase{
List<String> argList;
public MyTest(){
//read argList from File
}
testMyTest(){
//callmy api
myApi(arg1);
}
}
Now i want make a seperate testcase for each of the 50 args.Args are read from File. I dont want to write a seperate method for calling myApi with different args.How can i do it?
I dont want to write sperate methods like
testMyTest1(){
//callmy api
myApi(arg1);
}
testMyTest1(){
//callmy api
myApi(arg2);
}
You can use a parameterized test for this.
You can use a Parameterized tests or Theories (since JUnit 4.4). For more details use
http://blogs.oracle.com/jacobc/entry/parameterized_unit_tests_with_junit
http://blogs.oracle.com/jacobc/entry/junit_theories
private static final String[] args = new String[] {.....};
#Test
public void myTest(){
for (int i=0; i<args.length; i++){
myApi(args[i];
}
}
The above answers your question I think, however it is not good JUnit practice. It is best that each test method only invokes the method under test one time with one test condition. That way if multiple things are wrong, you get a separate error for each rather than dealing with one at a time. This would suggest the following:
private static final String[] args = new String[] {.....};
private void testMyTest(String arg){
myApi(arg);
}
#Test
public void myTest0(){
testMyTest(args[0]);
}
#Test
public void myTest1(){
testMyTest(args[1]);
}
Probably the best mechanism is to do the first option above but using the ErrorCollector rule to allow for multiple errors to be reported.
Edit I stand corrected, jordao's answer regarding parameterized tests is really the best way to do this.
Unit testing usually is made with assertions. You don't need to write a method for each argument, but execute different assertions based on your arguments.
One way for doing it would be:
class MyApiTest extends TestCase {
List<String> argList;
public MyApiTest() {}
public testMyApi() {
assertTrue(testMyApi(arg1));
assertFalse(testMyApi(arg2));
assertNull(testMyApi(arg3));
assertEquals(testMyApi(arg4), testMyApi(arg5));
}
}
I'd even prefer using annotations, like
class MyApiTest {
#Before
public setUp() {}
#After
public tearDOwn() {}
#Test
public testMyApi() {
Assert.assertTrue(testMyApi(arg1));
Assert.assertFalse(testMyApi(arg2));
Assert.assertNull(testMyApi(arg3));
Assert.assertEquals(testMyApi(arg4), testMyApi(arg5));
}
}
Suppose, I have a junit test class:
class MyComponentTest {
private void test(File file) {...}
#Test public void test1() {test("test1.txt")}
#Test public void test2() {test("test2.txt")}
#Test public void test3() {test("test3.txt")}
}
The test method reads the input data from the file and test the component with the input data.
What if I am changing the MyComponentTest ?
class MyComponentTest {
private void test(File file) {...}
#Test public void testAll() {
for (String name: dir.list())
test(new File(name))
}
}
Now I have only one test (testAll) instead of three tests (test1, test2, and test3) as it was before. The Runner for example will not recognize three separate tests as it did in the previous version of the class.
My question is: how to make each test method invocation a separate test from the junit point of view ?
Though you can use Junit's Parameterized tests for this it is bit involved and ugly. I suggest you looking at the spockframework which simplifies this a lot. And there is also another option in TestNG.
OK, so the #Ignore annotation is good for marking that a test case shouldn't be run.
However, sometimes I want to ignore a test based on runtime information. An example might be if I have a concurrency test that needs to be run on a machine with a certain number of cores. If this test were run on a uniprocessor machine, I don't think it would be correct to just pass the test (since it hasn't been run), and it certainly wouldn't be right to fail the test and break the build.
So I want to be able to ignore tests at runtime, as this seems like the right outcome (since the test framework will allow the build to pass but record that the tests weren't run). I'm fairly sure that the annotation won't give me this flexibility, and suspect that I'll need to manually create the test suite for the class in question. However, the documentation doesn't mention anything about this and looking through the API it's also not clear how this would be done programmatically (i.e. how do I programatically create an instance of Test or similar that is equivalent to that created by the #Ignore annotation?).
If anyone has done something similar in the past, or has a bright idea of how else I could go about this, I'd be happy to hear about it.
The JUnit way is to do this at run-time is org.junit.Assume.
#Before
public void beforeMethod() {
org.junit.Assume.assumeTrue(someCondition());
// rest of setup.
}
You can do it in a #Before method or in the test itself, but not in an #After method. If you do it in the test itself, your #Before method will get run. You can also do it within #BeforeClass to prevent class initialization.
An assumption failure causes the test to be ignored.
Edit: To compare with the #RunIf annotation from junit-ext, their sample code would look like this:
#Test
public void calculateTotalSalary() {
assumeThat(Database.connect(), is(notNull()));
//test code below.
}
Not to mention that it is much easier to capture and use the connection from the Database.connect() method this way.
You should checkout Junit-ext project. They have RunIf annotation that performs conditional tests, like:
#Test
#RunIf(DatabaseIsConnected.class)
public void calculateTotalSalary() {
//your code there
}
class DatabaseIsConnected implements Checker {
public boolean satisify() {
return Database.connect() != null;
}
}
[Code sample taken from their tutorial]
In JUnit 4, another option for you may be to create an annotation to denote that the test needs to meet your custom criteria, then extend the default runner with your own and using reflection, base your decision on the custom criteria. It may look something like this:
public class CustomRunner extends BlockJUnit4ClassRunner {
public CTRunner(Class<?> klass) throws initializationError {
super(klass);
}
#Override
protected boolean isIgnored(FrameworkMethod child) {
if(shouldIgnore()) {
return true;
}
return super.isIgnored(child);
}
private boolean shouldIgnore(class) {
/* some custom criteria */
}
}
Additionally to the answer of #tkruse and #Yishai:
I do this way to conditionally skip test methods especially for Parameterized tests, if a test method should only run for some test data records.
public class MyTest {
// get current test method
#Rule public TestName testName = new TestName();
#Before
public void setUp() {
org.junit.Assume.assumeTrue(new Function<String, Boolean>() {
#Override
public Boolean apply(String testMethod) {
if (testMethod.startsWith("testMyMethod")) {
return <some condition>;
}
return true;
}
}.apply(testName.getMethodName()));
... continue setup ...
}
}
A quick note: Assume.assumeTrue(condition) ignores rest of the steps but passes the test.
To fail the test, use org.junit.Assert.fail() inside the conditional statement. Works same like Assume.assumeTrue() but fails the test.