I have some common set up code that I've factored out to a method marked with #Before. However, it is not necessary for all this code to run for every single test. Is there a way to mark it so the #Before method only runs before certain tests?
Just move out the tests that don't need the setup code into a separate test class. If you have some other code common to the tests that would be helpful to keep, move that out into a helper class.
#Nested + #BeforeEach
Totally agree with the point of moving the related code to an inner class. So here what I have done.
Create an inner class inside your test class
Annotate the inner class with #Nested
Move all the test methods you want to use in the inner class
Write the init code inside the inner class and annotate it with #BeforeEach
Here is the code:
class Testing {
#Test
public void testextmethod1() {
System.out.println("test ext method 1");
}
#Nested
class TestNest{
#BeforeEach
public void init() {
System.out.println("Init");
}
#Test
public void testmethod1() {
System.out.println("This is method 1");
}
#Test
public void testmethod2() {
System.out.println("This is method 2");
}
#Test
public void testmethod3() {
System.out.println("This is method 3");
}
}
#Test
public void testextmethod2() {
System.out.println("test ext method 2");
}
}
Here is the output
test ext method 1
test ext method 2
Init
This is method 1
Init
This is method 2
Init
This is method 3
Note: I am not sure if this is supported in Junit4. I am doing this in JUnit5
It is possible to achieve also via Assume from JUnit. And then you can check the method name for which you want to process #Before.
public class MyTest {
#Rule
public TestName testName = new TestName();
#Before
public void setUp() {
assumeTrue(testName.getMethodName().equals("myMethodName"));
// setup follows
}
}
Check the topic for more insights about #Rule.
Now that it's 2023, I'd recommend sticking with JUnit 5.x
I'd also say that this is probably a micro-optimization. I would not go to the effort until I measured my test time and saw that running the code when it wasn't necessary added a significant amount of time.
Not sure about #Before, but I recently came up with a strategy for #After block to run selectively. The implementation was straight forward. I have some flags set to default values as part of the test class. They are reset to default values in #Before class. In the class I need to do things specific to a flag, I set those flags & in #After I check for flag values to do the respective jobs.
JUnit 4.12 provide Enclosed Runner like
#RunWith(Enclosed.class)
public class GlobalTest{
#RunWith(MockitoJUnitRunner.class)
public class InnerTest{
}
}
Related
I have a test class containing test cases for say blue and non-blue devices. If the parameter isBlue is set then it should run only those test case that have say the #Blue annotation. I am not sure how to implement this specific annotation that will achieve this functionality.
public class TestClass {
boolean isBlue = false;
#Before
public void setUp () {
isBlue = MyApplication.instance().isBlue();
}
#Test
public void testA () { ... }
#Test #Blue
public void testB() { ... }
}
In this example if isBlue is true then it should only run testB() otherwise it should run all test cases
Take a look at JUnit runners. Nice explanation of runners
You can create your own runner which will extend on BlockJUnit4ClassRunner.
You can override
#Override
protected List<FrameworkMethod> getChildren() {
// scan test class for methonds annotated with #Test
}
To additionally filter by methods that have your custom annotation set, and your property in the application is set as well.
I think you are on the wrong path.
You want your test cases to help identifying problems; and assist you in fixing them. Anything that "distracts" you from that purpose reduces the values of your unit tests.
Thus: don't put tests that have really "different" scope into the same test class. Especially from the point of view: how would you control what "MyApplication.instance()" would return? That sounds like a problem in itself.
Meaning: you want to have two independent tests; and those don't rely on some "static" object telling them something. They test what is in their scope; nothing else.
By using jUnit Assume
#Test
public void testA () {
assumeTrue(MyApplication.instance().isBlue());
...
}
A failing assumption in a #Before or #BeforeClass method will have the same effect as a failing assumption in each #Test method of the class.
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.
Is it possible to run a JUnit #Test method in a class that has a method annotated with #Before, but to ignore the #Before method only for this test?
Edit: I am interested if JUnit supports this functionality, not workarounds. I am aware of workarounds like moving the test(s) in another class or removing the annotation and manually calling setUp() in each test method.
Suppose in a class there are 30 tests, and for 29 of them #Before really simplifies the testing initialization, but for one (or more than one) of them is useless/it complicates things.
public class MyTestClass {
#Before
public void setUp() {
//setup logic
}
#Test
public void test1() {
//[...]
}
#Test
public void test2() {
//[...]
}
//more tests here
#Test(ignoreBefore = true, ignoreAfter = true //false by default)
//something equivalent to this
public void test20() {
//[...]
}
}
You can do this with a TestRule. See my answer to Exclude individual test from 'before' method in JUnit. Basically, implement ExternalResource, and in the apply method, check if there is a specific annotation on the method, and if there is, don't run the before/after method. You'll have to specifically call the before/after from your rule though.
If it useless it should not be a problem - does it harm to run the setUp once more?
However I don't think it's possible and looks for me as a cripple feature.
Another approach - move that test to a separate test-class.
With JUnit 5 You can have nested tests using #Nested annotation :
public class MainClass {
#Nested
class InnerClass1 {
#BeforeEach
void setup(){}
#Test
void test1(){}
}
#Nested
class InnerClass2 {
// No setup
#Test
void test2(){}
}
}
Just to add to this, something that I found out on a recent visit to this area.
Junit/Mockito seems to give preference to mocking behavior defined in a test, over a #Before annotated method.
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.
We have DAO tests that should run against both the real DAO/database, and against a mock dao to verify that the mock dao behaves the same as the real dao. To this end, we have a structure like this:
public abstract class DAOTestBase
{
public void testSimple()
{
// dummy assertion
assertTrue(true, "Hello");
}
}
#Test(groups = "fast")
public class TestMockDAO extends DAOTestBase
{
// setUp/tearDown and helper methods for mock
}
#Test(groups = "slow")
public class TestDAO extends DAOTestBase
{
// setUp/tearDown and helper methods for real DB
}
Unfortunately this doesn't work - TestNG doesn't think that the testSimple method is a test and hence won't run it. So instead I tried to annotate the testSimple method (or the DAOTestBase class):
A #Test annotation without any groups will lead to the same effect - the test won't run for either fast nor slow groups.
A #Test annotation with groups fast and slow will lead to the opposite effect - both TestMockDAO and TestDAO will be run regardless of whether only fast or only slow tests should be run.
A #Test annotation with a different group, say common, plus added dependsOnGroups="common" annotations in both TestMockDAO and TestDAO will also not work unless common is included in the groups to run which leads again to case 2 above (both TestMockDAO and TestDAO are run).
In the end, what I'm looking for is a way to be able to define the group for the inherited tests in the sub class, but it seems as if the #Test annotation is only applied to test methods in that very same class, not also to inherited methods that don't have a #Test annotation. Is there any other way to achieve this (without overriding all methods in the sub classes) ?
I am currently working through a similar situation.
A way to make test cases run is to use something like:
#Test
public void someTest() {
TestNG testng = new TestNG();
testng.setTestClasses(new Class[] { SomeTests.class });
testng.run();
}
Reference: http://testng.org/doc/documentation-main.html#running-testng-programmatically
Unforunately I am currently unable to get it to report the test cases within SomeTests.
Have you tried simply adding a #Test annotation on top of DAOTestBase? Each subclass will override it with its own group and this should make the method in the base a test method.
I am using TestNG 6.14.3 version and I found a solution using priority annotation.
Example:
I have a base test class:
public class TestBase {
#Test(priority = 0)
public void testA() {
assertTrue(true, "testA");
}
}
And another extended test class:
public class Test2 extends TestBase {
#Test(priority = 1)
public void testB() {
assertTrue(true, "testB");
}
}
When I run Test2 test class, I obtain the following esult:
testA: true
testB: true
I solved it this way:
The methods in the base class are in "base" group, but need to check if the test have been initialized.
public abstract DaoTestBase {
private boolean initialized = false;
#Test(groups = "base")
public void testSimple() {
if (!initialized) { return; }
// dummy assertion
assertTrue(true, "Hello");
}
}
The test is initialized in the child, in the BeforeClass annotated method.
#BeforeClass
protected void initialize() {
super.initialized = true;
}
If you annotate the parent class instead of the methods, you must pass inheritGroups=false and the group, since it inherits also the group of the base class and it will not work.
Now, you must run TestNG to check groups base,fast or base,slow. Both tests will be executed, but the one not initialized will do nothing.
It is ugly, and I would not recommend it (it looks better to redefine the methods in child and call the according super method), but in my case I need priority in my test methods, and I want to avoid that repetition in each child class.