Is there a way to get Gradle (1.12) to list all of the available unit test classes in a project?
I'm considering putting a front-end on a series of tests we use in my company, and since new tests are always being added, I need a way to get a list of available tests.
I realize that I could scan the actual project for classes that reside in the test sources tree, but I was hoping for something easily parsed from Gradle. I just don't know if that's really an option and I'm having trouble getting decent search results since "test" is such a generic word.
Any help would be appreciated.
There is no official API in Gradle to expose this information. You can check if ClassScanner.java is what you need. Either look at Gradle sources or it is also used in EclipseTestExecuter.java Keep in mind that it is an implementation detail.
A simpler approach is to run these tests and enable logging where you will print names of executed tests. There is an example how to this in Gradle documentation I think.
I am working on some application in Java and writing JUnit tests. I have a design question about Unit Testing. I have one class that reads a file and Create object called Song by reading different lines and parsing based on some algorithm. I have written some unit test on that. Next step after parsing is to actually convert that song to a different format based on some properties of Song object. I have another class that works as a translator. There is a method translate that takes Song object as input. Now in unit test for translator. I need a Song object with all valid properties. I am confused here that should I create a new Song object by putting same functionality as in parser or should I call the parser service to do that for me. I feel it will not be isolated if I take the second option. But in first option it's like duplicate code. Can somebody guide me on this?
There's nothing wrong in using a Builder in order to create the input data for a SUT invocation when this data is complex, however I see 2 risks here.
If the builder fails your test will fail too, but it shouldn't. As you said unit tests should be isolated from external code.
If you use code coverage as a metric to evaluate how good your unit tests are (I don't mean this is right), by looking at the builder's coverage you'll be tempted to think it's tested though obviously isn't.
My opinion is there's not a best solution fitting all the scenarios. In case the input data is not very complex try to build it "manually", otherwise use the builder.
I'm currently working on a large scale business application and I'm going to use Solver Foundation with Solver Foundation Services to solve a huge portfolio optimization problem with user defined constraints and input. The problem will usually be around 5-10 000 variables and a couple of thousand constraints.
I've started the development using SFS, but I'm having serious trouble unit testing my code. I want to test that the problem I've set up is correct, that all constraints have the correct input and that all parameters are set up correct. But to do that i need to write unit tests againts the SolverContext, and more spesifically, the Parameter objects and the Constraint objects. And these classes are completely sealed up. I can't seem to get any information out of them except their name, expression and index sets.
Is there any way to test the value of a parameter for a given index?
I.e.
var value = myParameter.GetValueFor(anObjectsID);
Assert.That(value, Is.EqualTo(expectedValue);
I can't seem to find any documentation or articles concerning Solver Foundation and unit testing.
Any ideas or comments?
Julian
I'm a controls developer and a relative newbie to unit testing. Almost daily, I fight the attitude that you cannot test controls because of the UI interaction. I'm producing a demonstration control to show that it's possible to dramatically reduce manual testing if the control is designed to be testable. Currently I've got 50% logic coverage, but I think I could bump that up to 75% or higher if I could find a way to test some of the more complicated parts.
For example, I have a class with properties that describe the control's state and a method that generates a WPF PathGeometry object made of several segments. The implementation looks something like this:
internal PathGeometry CreateOuterGeometry()
{
double arcRadius = OuterCoordinates.Radius;
double sweepAngle = OuterCoordinates.SweepAngle;
ArcSegment outerArc = new ArcSegment(...);
LineSegment arcEndToCenter = new LineSegment(...);
PathFigure fig = new PathFigure();
// configure figure and add segments...
PathGeometry outerGeometry = new PathGeometry();
outerGeometry.Figures.Add(fig);
return outerGeometry;
}
I've got a few other methods like this that account for a few hundred blocks of uncovered code, an extra 25% coverage. I originally planned to test these methods, but rejected the notion. I'm still a unit testing newbie, and the only way I could think of to test the code would be several methods like this:
void CreateOuterGeometry_AngleIsSmall_ArcSegmentIsCorrect()
{
ClassUnderTest classUnderTest = new ClassUnderTest();
// configure the class under test...
ArcSegment expectedArc = // generate expected Arc...
PathGeometry geometry = classUnderTest.CreateOuterGeometry()
ArcSegment arc = geometry.Figures.Segments[0];
Assert.AreEqual(expectedArc, arc)
}
The test itself looks fine; I'd write one for each expected segment. But I had some problems:
Do I need tests to verify "Is the first segment an ArcSegment?" In theory the test tests this, but shouldn't each test only test one thing? This sounds like two things.
The control has at least six cases for calculation and four edge cases; this means for each method I need at least ten tests.
During development I changed how the various geometries were generated several times. This would cause me to have to rewrite all of the tests.
The first problem gave me pause because it seemed like it might inflate the number of tests. I thought I might have to test things like "Were there x segments?" and "Is segment n the right type?", but now that I've thought more I see that there's no branching logic in the method so I only need to do those tests once. The second problem made me more confident that there would be much effort associated with the test. It seems unavoidable. The third problem compounds the first two. Every time I changed the way the geometry was calculated, I'd have to edit an estimated 40 tests to make them respect the new logic. This would also include adding or removing tests if segments were added or removed.
Because of these three problems, I opted to write an application and manual test plan that puts the control in all of the interesting states and asks the user to verify it looks a particular way. Was this wrong? Am I overestimating the effort involved with writing the unit tests? Is there an alternative way to test this that might be easier? (I'm currently studying mocks and stubs; it seems like it'd require some refactoring of the design and end up being approximately as much effort.)
Use dependency injection and mocks.
Create interfaces for ArcSegmentFactory, LineSegmentFactory, etc., and pass a mock factory to your class. This way, you'll isolate the logic that is specific to this object (this should make testing easier), and won't be depending on the logic of your other objects.
About what to test: you should test what's important. You probably have a timeline in which you want to have things done, and you probably won't be able to test every single thing. Prioritize stuff you need to test, and test in order of priority (considering how much time it will take to test). Also, when you've already made some tests, it gets much easier to create new tests for other stuff, and I don't really see a problem in creating multiple tests for the same class...
About the changes, that's what tests are for: allowing you to change and don't really fear your change will bring chaos to the world.
You might try writing a control generation tool that generates random control graphs, and test those. This might yield some data points that you might not have thought of.
In our project, we use JUnit to perform tests which are not, strictly speaking, unit tests. We find, for example, that it's helpful to hook up a blank database and compare an automatic schema generated by Hibernate (an Object-Relational Mapping tool) to the actual schema for our test database; this helps us catch a lot of issues with wrong database mappings. But in general... you should only be testing one method, on one class, in a given test method. That doesn't mean you can't do multiple assertions against it to examine various properties of the object.
My approach is to convert the graph into a string (one segment per line) and compare this string to an expected result.
If you change something in your code, tests will start to fail but all you need to do is to check that the failures are in the right places. Your IDE should offer a side-by-side diff for this.
When you're confident that the new output is correct, just copy it over the old expected result. This will make sure that a mistake won't go unnoticed (at least not for long), the tests will still be simple and they are quick to fix.
Next, if you have common path parts, then you can put them into individual strings and build the expected result of a test from those parts. This allows you to avoid repeating yourself (and if the common part changes, you just have to update a single place for all tests).
If I understand your example correctly, you were trying to find a way to test whether a whole bunch of draw operations produce a given result.
Instead of human eyes, you could have produced a set of expected images (a snapshot of verified "good" images), and created unit tests which use the draw operations to create the same set of images and compare the result with an image comparison. This would allow you to automate the testing of the graphic operations, which is what I understand your problem to be.
The textbook way to do this would be to move all the business logic to libraries or controllers which are called by a 1 line method in the GUI. That way you can unit test the controller or library without dealing with the GUI.
I have a simple project, mostly consisting of back-end service code. I have this fully unit-tested, including my DAL layer...
Now I have to write the front-end. I re-use what business objects I can in my front-end, and at one point I have a grid that renders some output. I have my DAL object with some function called DisplayRecords(id) which displays the records for a given ID...
All of this DAL objects are unit tested. But is it worth it to write a unit test for the DisplayRecords() function? This function is calling a stored proc, which is doing some joins. This means that my unit-test would have to set-up multiple tables, one with 15 columns, and its return value is a DataSet (this is the only function in my DAL that returns a datset - because it wasnt worth it to create an object just for this one grid)...
Is stuff like this even worth testing? What about front-end logic in general - do people tend to skip unit tests for the ASP.NET front-end, similar to how people 'skip' the logic for private functions? I know the latter is a bit different - testing behavior vs implementation and all... but, am just curious what the general rule-of-thumb is?
Thanks very much
There are a few things that weigh into whether you should write tests:
It's all about confidence. You build tests so that you have confidence to make changes. Can you confidently make changes without tests?
How important is this code to the consumers of the application? If this is critical and central to everything, test it.
How embarrassing is it if you have regressions? On my last project, my goal was no regressions-- I didn't want the client to have to report the same bug twice. So every important bug got a test to reproduce it before it was fixed.
How hard is it to write the test? There are many tools that can help ease the pain:
Selenium is well understood and straightforward to set up. Can be a little expensive to maintain a large test suite in selenium. You'll need the fixture data for this to work.
Use a mock to stub out your DAL call, assuming its tested elsewhere. That way you can save time creating all the fixture data. This is a common pattern in testing Java/Spring controllers.
Break the code down in other ways simply so that it can be tested. For example, extract out the code that formats a specific grid cell, and write unit tests around that, independent of the view code or real data.
I tend to make quick Selenium tests and just sit and watch the app do its thing - that's a fast validation method which avoids all the manual clicking.
Fully automated UI testing is tedious and should IMO only be done in more mature apps where the UI won't change much. Regarding the 'in-between' code, I would test it if it is reused and/or complicated/ introducing new logic, but if its just more or less a new sequence of DAL method calls and specific to a single view I would skip it.