How do I use TestNG SkipException? - unit-testing

How do I use TestNG throw new SkipException() effectively? Does anyone have an example?
I tried throwing this exception at the start of a test method but it blows up the teardown, setup, methods, etc. , and has collateral damage by causing a few (not all) of the subsequent tests to be skipped also, and shows a bunch of garbage on the TestNG HTML report.
I use TestNG to run my unit tests and I already know how to use an option to the #Test annotation to disable a test. I would like my test to show up as "existent" on my report but without counting it in the net result. In other words, it would be nice if there was a #Test annotation option to "skip" a test. This is so that I can mark tests as ignored sortof without having the test disappear from the list of all tests.
Is "SkipException" required to be thrown in #BeforeXXX before the #Test is ran? That might explain the wierdness I am seeing.

Yes, my suspicion was correct. Throwing the exception within #Test doesn't work, and neither did throwing it in #BeforeTest, while I am using parallel by classes. If you do that, the exception will break the test setup and your TestNG report will show exceptions within all of the related #Configuration methods and may even cause subsequent tests to fail without being skipped.
But, when I throw it within #BeforeMethod, it works perfectly. Glad I was able to figure it out. The documentation of the class suggests it will work in any of the #Configuration annotated methods, but something about what I am doing didn't allow me to do that.
#BeforeMethod
public void beforeMethod() {
throw new SkipException("Testing skip.");
}

I'm using TestNG 6.8.1.
I have a few #Test methods from which I throw SkipException, and I don't see any weirdness. It seems to work just as expected.
#Test
public void testAddCategories() throws Exception {
if (SupportedDbType.HSQL.equals(dbType)) {
throw new SkipException("Using HSQL will fail this test. aborting...");
}
...
}
Maven output:
Results :
Tests run: 85, Failures: 0, Errors: 0, Skipped: 2

While using DataProvider empty test using Apache POI create seperate check #BeforeTest we can skip the data base is empty or null in that scenario we can use this skiptest with row check is empty using boolean true check then skipped that expection do not go to entire check its having 1000 input check rather its skip that data provider null...

For skipping test case from #Test annotation option you can use 'enable=false' attribute with #Test annotation as below
#Test(enable=false)
This will skip the test case without running it. but other tests, setup and teardown will run without any issue.

Related

Flag test as expected to fail in unit 5

I have a unit test, written with JUnit 5 (Jupiter), that is failing. I do not currently have time to fix the problem, so I would like to mark the test as an expected failure. Is there a way to do that?
I see #Disable which causes the test to not be run. I would like the test to still run (and ideally fail the build if it starts to work), so that I remember that the test is there.
Is there such an annotation in Junit 5? I could use assertThrows to catch the error, but I would like the build output to indicate that this is not a totally normal test.
You can disable the failing test with the #Disabled annotation. You can then add another test that asserts the first one does indeed fail:
#Test
#Disabled
void fixMe() {
Assertions.fail();
}
#Test
void fixMeShouldFail() {
assertThrows(AssertionError.class, this::fixMe);
}

How do I declare that I "expect" an exception in a unit test with Groovy, JUnit and Maven?

I have the following Groovy unit test code:
class MyTest extends GroovyTestCase {
#Test(expected = IllegalArgumentException.class)
public void testReadFileMissing() {
// does something which causes an IllegalArgumentException
}
// more tests
}
This works perfectly with my Java unit tests, but with groovy tests, mvn clean test runs the test, but the test fails because an IllegalArgumentException was thrown. In other words, my "expected" annotation attribute seems to be completely ignored.
I could of course simply use a try/catch block to check the behaviour I'm interested in, but I'd like to use the JUnit API if possible because that's what it's for and I find the resulting code simpler to read and understand.
So, can anyone tell me what I'm doing wrong?
either don't use GroovyTestCase and the according JUnit class instead as base or go full groovy and use shouldFail. examples are here http://mrhaki.blogspot.de/2009/11/groovy-goodness-testing-for-expected.html
You can use shouldFail or shouldFailWithCause showcasing exactly which kind of exception is expected from the code under test.

Conflicting results when unit testing MVC controller

I'm writing unit tests (using NUnit & Moq) for my MVC 2 controllers, and am following examples in the Pro ASP.net MVC 2 Framework book by Steven Sanderson (great book, btw). However, I've run into problems, which I think are just due to my lack of understanding of NUnit.
Here's an excerpt, with the irrelevant parts removed:
[Test]
public void Cannot_Save_Invalid_Event()
{
...
repository.Setup(x => x.SaveEvent(evt)).Callback(Assert.Fail);
...
repository.Verify(x => x.SaveEvent(evt));
}
This test is passing for me, although from what I understand, those two statements should directly conflict with each other. The second one wasn't there originally, but I put it in to verify that it was passing for the right reasons.
From what I understand, my repository is set up to fail if "repository.SaveEvent(evt)" is called. However, later in the test, I try to verify that "repository.SaveEvent(evt)" was called. Since it passes, doesn't this mean that it was both called, and not called? Perhaps those statements don't act as I suspect they do.
Can someone explain how these two statements are not opposites, and how they can both exist and the test still pass?
Maybe your tests doesn-t fail beacuse it has a catch-everything block that also hides the assert/verify-exception that is necessary for the test to fail.
Note: the following unittest will allways pass
[Test]
public void HidingAssertionFailure()
{
try {
Assert.AreEqual(0,1); // this should fail
} catch (Exception ex) {
// this will hide the assertion failure
}
}
The reason for this behavior was that it was running "SaveEvent()", however, since the mocked repository didn't define that action, it was throwing an exception in my controller, which my controller was catching.
So, it seems that the callback will only execute if control returns successfully.

How do I ignore a test based on another test in NUnit?

I'm writing some NUnit tests for database operations. Obviously, if Add() fails, then Get() will fail as well. However, it looks deceiving when both Add() and Get() fail because it looks like there's two problems instead of just one.
Is there a way to specify an 'order' for tests to run in, in that if the first test fails, the following tests are ignored?
In the same line, is there a way to order the unit test classes themselves? For example, I would like to run my tests for basic database operations first before the tests for round-tripping data from the UI.
Note: This is a little different than having tests depend on each other, it's more like ensuring that something works first before running a bunch of tests. It's a waste of time to, for example, run a bunch of database operations if you can't get a connection to the database in the first place.
Edit: It seems that some people are missing the point. I'm not doing this:
[Test]
public void AddTest()
{
db.Add(someData);
}
[Test]
public void GetTest()
{
db.Get(someData);
Assert.That(data was retrieved successfully);
}
Rather, I'm doing this:
[Test]
public void AddTest()
{
db.Add(someData);
}
[Test]
public void GetTest()
{
// need some way here to ensure that db.Add() can actually be performed successfully
db.Add(someData);
db.Get(somedata);
Assert.That(data was retrieved successfully);
}
In other words, I want to ensure that the data can be added in the first place before I can test whether it can be retrieved. People are assuming I'm using data from the first test to pass the second test when this is not the case. I'm trying to ensure that one operation is possible before attempting another that depends on it.
As I said already, you need to ensure you can get a connection to the database before running database operations. Or that you can open a file before performing file operations. Or connect to a server before testing API calls. Or...you get the point.
NUnit supports an "Assume.That" syntax for validating setup. This is documented as part of the Theory (thanks clairestreb). In the NUnit.Framework namespace is a class Assume. To quote the documentation:
/// Provides static methods to express the assumptions
/// that must be met for a test to give a meaningful
/// result. If an assumption is not met, the test
/// should produce an inconclusive result.
So in context:
public void TestGet() {
MyList sut = new MyList()
Object expecting = new Object();
sut.Put(expecting);
Assume.That(sut.size(), Is(1));
Assert.That(sut.Get(), Is(expecting));
}
Tests should never depend on each other. You just found out why. Tests that depend on each other are fragile by definition. If you need the data in the DB for the test for Get(), put it there in the setup step.
I think the problem is that you're using NUnit to run something other than the sort of Unit Tests that NUnit was made to run.
Essentially, you want AddTest to run before GetTest, and you want NUnit to stop executing tests if AddTest fails.
The problem is that that's antithetical to unit testing - tests are supposed to be completely independent and run in any order.
The standard concept of Unit Testing is that if you have a test around the 'Add' functionality, then you can use the 'Add' functionality in the 'Get' test and not worry about if 'Add' works within the 'Get' test. You know 'Add' works - you have a test for it.
The 'FIRST' principle (http://agileinaflash.blogspot.com/2009/02/first.html) describes how Unit tests should behave. The test you want to write violates both 'I' (Isolated) and 'R' (Repeatable).
If you're concerned about the database connection dropping between your two tests, I would recommend that rather than connect to a real database during the test, your code should use some sort of a data interface, and for the test, you should be using a mock interface. If the point of the test is to exercise the database connection, then you may simply be using the wrong tool for the job - that's not really a Unit test.
I don't think that's possible out-of-box.
Anyway, your test class design as you described will make the test code very fragile.
MbUnit seems to have a DependsOnAttribute that would allow you to do what you want.
If the other test fixture or test
method fails then this test will not
run. Moreover, the dependency forces
this test to run after those it
depends upon.
Don't know anything about NUnit though.
You can't assume any order of test fixture execution, so any prerequisites have to be checked for within your test classes.
Segregate your Add test into one test-class e.g. AddTests, and put the Get test(s) into another test-class, e.g. class GetTests.
In the [TestFixtureSetUp] method of the GetTests class, check that you have working database access (e.g. that Add's work), and if not, Assert.Ignore or Inconclusive, as you deem appropriate.
This will abort the GetTests test fixture when its prerequisites aren't met, and skip trying to run any of the unit tests it contains.
(I think! I'm an nUnit newbie.)
Create a global variable and return in the test for Get unless Add set it to true (do this in the last line of Add):
public boolean addFailed = false;
public void testAdd () {
try {
... old test code ...
} catch (Throwable t) { // Catch all errors
addFailed = true;
throw t; // Don't forget to rethrow
}
}
public void testGet () {
if (addFailed) return;
... old test code ...
}

How do I write NUnit unit tests without having to surround them with try catch statements?

At my company we are writing a bunch of unit tests. What we'd like to have done is for the unit tests to execute and whenever one succeeds or fails at the end of the test we can write that somewhere but we don't want to put that logic in every test.
Any idea how we could just write tests without having to surround the content of the test with the try catch logic that we've been using?
I'm guessing you do something like this:
[Test]
public void FailBecauseOfException()
{
try
{
throw new Exception();
}
catch (Exception e)
{
Assert.Fail(e.Message);
}
}
There is no need for this. The tests will fail automatically if they throw an exception. For example, the following test will show up as a failure:
[Test]
public void FailBecauseOfException()
{
throw new Exception();
}
I'm not entirely sure what you are trying to do here. Are you saying you are wrapping it in a try/catch so that you can catch when an exception occurs and log this?
If so, then a better way, probably, is just to get NUnit to write an output file and use this. I haven't used NUnit for about a year, but IIRC you can redirect its output to any file you like using the /out directive.
If there is a reason why you have to log it the way you say, then you'll either have to add your custom code to each test, or have a common "runner" that takes your code (for each test) as an anonymous method and runs it inside a single try..catch. That would prevent you having to repeat the try..catch for every test.
Apologies if I've misunderstood the question.
MSTest has TestCleanup, which runs after every test. In NUnit, the attribute to be used is TearDown (after every test) or TestFixtureTearDown (after all the test are completely). This executes after the end of each test.
If you want something to run just in case a test passes, you could have a member variable shouldRunExtraMethod, which is initialized to false before each test, and is changed to true at the end of the test. And on the TearDown, you only execute it depending on this variable value
If your unit test method covers the scenario in which you expect exceptions to be thrown, use the ExpectedException attribute. There's a post here on SO about using that attribute.
Expect exceptions in nUnit...
NUnit assert statements all have an option to print a message for each test for when it fails.
Although if you'd like to have it write out something somewhere at the end of each test, you can set it up in the teardown of each method. Just set the string to what you want written inside the test itself, and during teardown (which happens after each test) It can do whatever you want with it.
I'm fairly certain teardown occurs even if an exception is thrown. That should do what you're wanting.
The problem you have is that the NUnit Assert.* methods will throw an AssertionException whenever an assert fails - but it does nothing else. So it doesn't look like you can check anything outside of the unit test to verify whether the test failed or not.
The only alternative I can think of is to use AOP (Aspect Oriented Programming) with a tool such as PostSharp. This tool allows you to create aspects that can act on certain events. For example:
public class ExceptionDialogAttribute : OnExceptionAspect
{
public override void OnException(MethodExecutionEventArgs eventArgs)
{
string message = eventArgs.Exception.Message;
Window window = Window.GetWindow((DependencyObject) eventArgs.Instance);
MessageBox.Show(window, message, "Exception");
eventArgs.FlowBehavior = FlowBehavior.Continue;
}
}
This aspect is code which runs whenever an exception is raised:
[ExceptionDialog]
[Test]
public void Test()
{
assert.AreEqual(2, 4);
}
Since the above test will raise an exception, the code in ExceptionDialogAttribute will run. You can get information about the method, such as it's name, so that you can log it into a file.
It's been a long time since I used PostSharp, so it's worth checking out the examples and experimenting with it.