Testing tools need to be a part of the entire application lifecycle, be flexible in how they're used, and help companies take the next step towards DevOps.
[Ivan Zerin provides a primer on mocking methods that contain generic return types.] There are several cases where construction when().thenReturn is not suitable during Unit tests. One of then generic return type. I have faced such issue, let's take a look. There is a method in interface declaration: public interface FooInterface { public Iterable getList(); ... } Implementation looks like this: public class Foo implements FooInterface { public List getList() { ... } ... } At first mocking of such method should not be something unusual: public class UnitTest { @Mock private FooInterface mockFoo; @Test public void someUnitTest() { ... List testList = generateTestList(); when(mockFoo.getList()) .thenReturn(testList); } } But this code won't compile with error: Cannot resolve method 'thenReturn(List). Seems to be some mistake, cause returned type are correct from the interface point of view. This error happening cause compiler can not gurantee that returned type of method getList() will be List. Actually return type of method getList() in this case is Iterable and this means "Return some Iterable object with any objects that extends SomeClass". Let's rename this type as 'X'. So when(mockFoo.getList()) will create object OngoingStubbing> and it has method thenReturn(Iterable). Compiler can not tell what type X before runtime and cannot perform safe cast from List to Iterable (we perfrom actuall call of method thenReturn(List)). Sounds a little tricky but let's assume that SomeClass is standard Java class Number. Then classes Integer and Double are both fulfill the criteria of List. Let's say that as return type of mock we will use List, in this case, compiler should be ready that actual work with code during runtime will be performed with List too, but it is clearly that cast from Double to Integer will be incorrect (try to cast double value 12.6 to int). You could argue that in the case of mockito compiler won't need to bother about the casting of returned type because call of original method would not produce anything, but it is known by mockito. From compiler point of view, it is only Java code, that should be checked for safety and correctness before compiling. Ok, so how we should deal with such cases in mockito? Use doReturn() method: doReturn(testList).when(mockFoo).getList(); Such expression is not type safe, so it were designed for exceprional cases, so use it only when you cannot use standart when().thenReturn(), which is the type-safe, elegant and more readable syntax.
Logback is one of the most popular logging frameworks for Java, but did you know you could configure it using Groovy? This guide walks you through the whole process.
When testing it is often quite complicated to compare object with complex fields. By using the Unitils library in Java, this all becomes quite simple and elegant.
If you are using one of the many frameworks that say they are using JavaScript MVVM, you might not be using it the way it should be used. In this article, Dave Bush defines MVVM, analyzes its advantages, and provides some MVVM best practices to follow.
Code that makes use of external dependencies can be difficult to test. If you are using AWS, then you have no doubt run into issues in testing your code. This article takes you through how to get around this little hurdle by using AWS Stubs if you are using Ruby.
Monitoring, diagnosing, and troubleshooting are key activities in any enterprise application lifecycle, and logging is the core part of these activities. Meet Logback, a logging framework from the creator of Log4J.
This is an interesting topic because two ecosystems are mixed together and integrated. By picking a color from an app running on your Android smartphone, we will make an Arduino switch on a RGB LED of that same color.
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