BddStyle.UnitTesting

Provides set of base classes to structure Unit Tests in the BDD shape (Given-When-Then, GWT)

This projects gives an approach to solving few common tasks to achieve high quality UT code:

Note: this project contains two packages, depending on your UT framework of preference:

Few links:

Installing

Install-Package BddStyle.NUnit

(optional) For your convenience import Resharper templates to generate tests faster
- ReSharper => Tools => Templates Explorer => Import button

Tests are structured like: Given —< When —< Then
- Note that it is one-to-many ( —< ) relationship between the components
It can be read as: Given [initial context], When [event occurs], Then [ensure some outcomes]
- Given section describes the state of the world before you begin the test case in this scenario Can be thought of as the pre-conditions to the test
  - is represented by a folder in the solution structure
  - usually (optionally) contains Context class, which is a place to write the test setup
  - examples: given_tested_class; given_particular_environment_state
- When section is the case that you are specifying
  - is represented by a class located in the Given specified folder
  - usually this class is inherited from the Context class (optionally, otherwise inherited from ContextBase class - see below for details) therefore inheriting setup of the parent Given
  - example: when_sut_method1_is_called.cs
- Then section describes the changes you expect due to the specified behavior
  - is represented by a method in the When class marked with NUnit.Framework.TestAttribute
  - contains check of one expectation from the testcase execution results
  - examples: then_expected_result_is_returned(); then_exception_is_thrown();

How example solution looks like:

How example tests logical structure looks like:

Troubleshooting and error localization:

Example of the proposed inheritance model is: ContextBase -> given_description.Context.cs -> and_specified_given.Context -> when_class.cs

ContextBase - an entity provided by this library being the root entity and providing methods to override
- Members
  - Arrange(Async) - is called before each testcase execution to set up the preconditions. Is usually overriden in the Context (being the contents of the Given setup)
  - Act(Async) - contains the testcase actions to perform. Is usually overriden in the When class
  - Cleanup - is called after each testcase execution to cleanup the test consequences. Is usually overriden in the Context when such a cleanup is needed
  - SuppressAct - is a virtual property to allow disabling automatic Act execution (presuming it is going to be manually called in the test body). It is a solution to improve data-driven tests (aka TestCase in NUnit) implementation
As it can see from the example, nested Given is supported within the approach by creating nested folder (and Context class) with the methods overriden to specify the setup