Software development without test automation can no longer be considered professional. However, you might have existing code bases or want to rely on external libraries that may make writing effective and fast unit tests hard or even near to impossible. A typical work-around for these situations is to introduce test stubs for such external dependencies to make your code testable.
When you perform unit testing, there are many situations where you don’t have the full code or the right context that is needed to execute it. It might be that part of the code is not written yet or that you interact with an external system that is difficult to access or you don’t want to impact with unit tests. In these cases, you need to create a test double, an object that behaves like its production equivalent. In this article, Michał Lipski describes three types of test doubles – fake, stub and mock – and gives you examples when to use them in your unit testing.
Mockito is a popular and powerful open source Java mocking framework. In order to achieve good unit tests, you need to make use of mocks and stubs. And that’s exactly what this talk will be about: What is a mock?
Tests should save our money and time. How is it that they often become the stumbling block and slow down the work? They fail every time you try to do some refactoring and are difficult to maintain ultimately increasing the cost of software maintenance.
Tomek Kaczanowski writes that the idea behind its “Bad Tests, Good Tests” book is “to present test code snippets and discuss ways of making them better.” To achieve this goal, he explores a large amount of code and tests to discuss all the issues that you can meet in your software testing activities.
In unit testing, you use mocks to simulate the behavior of other code parts in controlled ways. mock is a Python library for testing that allows you to replace parts of the system under test with mock objects and make assertions about how they have been used. mock has been integrated the Python standard library since version 3.3 under the name unittest.mock.
In my previous column PHP Unit Testing with PHPUnit,I showed how to set up PHPUnit and how to run a few simple tests. You should be able to test any function or method now that doesn’t rely on making calls out to other methods or functions – which is of course very few, as most applications are a complex combination of methods and, in PHP’s case, functions.