Unit Tests And Automated Testing

Unit Tests & Automated Testing
Lee Englestone presents..
www.manchesterdeveloper.com

Agenda
Terminology
What, Why, How
Automating unit tests & testing
Advanced stuff
Test driven development (TDD)
Code coverage
What we wont be covering
Continuous Integration (in any depth)

Terminology (for the next hour)
Unit test
Tests a small bit of code (from code)
Integration test
Test after addition of code
System test / functional test
Test for adherence to user requirements
Regression test
Test that fixing / adding code hasn’t introduced bugs
Continuous integration
Automated checkout, building and testing of code from source control
Source : Lee & Wikipedia

Why should we TEST?
Why should we test at all?
£
£
REMEMBER
Testing is just one step in QA
£
£
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Testing different layers
Business Logic
Unit Tests
Web UI
Selenium

Three tier architecture
Web UI
ASPX, ASCX, HTML, Flash,
EpiServer Page Templates etc
Business Logic
Code libraries (DLLs)
Business Logic (DLL)
Database access
Data Access Layer

Testing business logic
Code libraries (DLLs)
Business Logic (DLL)
Unit Tests (DLL)
Unit Tests (DLLs)
Database access
Data Access Layer

Why have unit tests?
Why have unit tests?
Find bugs early / fast feedback
Increase QA
Why not to have unit tests
Increases development time?
CostOfWritingUnitTests < Sum(BugFixing)

Unit Testing
is not a Silver Bullet

What is a unit test?
“..tests if individual units of source code are fit for use.”
Should be
Small
Specific (only test 1 thing)
Clear pass / fail criteria

What does a unit test look like?
Using NUnit.Framework;
[TestFixture]
public class CarTests
{
[Test]
public void Test_Car_Paint ()
{
// Arrange
Color paint = Color.Red;
Car car = new Car();
// Act
car.paint(Color.Red);
// Assert
Assert.AreEqual(car.Color, paint);
}
…
}
Arrange
Act
Assert

Example unit test : Running
Running unit tests manually with NUnit

An example scenario
{ Code Example }
Objects
Car
Properties
ColorColor
double Value
double FuelLevel
double FuelCapacity
FuelTypeEnumFuelType
Methods
Car.Crush()
Car.Paint(Color)
Car.AddFuel(FuelTypeEnum, double)
Car.VeryImportantMethod()

Automating unit testing

Testing Web UI (Selenium)
What if we want to test the UI?
Manual recording and running
Can export to NUnit
Examples :
Community Fund Form
H1 checking**
{ Code Example }

Test driven development (TDD)
Write your tests, even BEFORE your code!
Make sure all tests initially fail
Then implement the code that the tests are testing
(Encourages Designing for Testing)

Code coverage
What % of your code base are you testing?

Summary
Test as early as possible
Design code to test
Separate BL from UI
Improve QA
Make unit tests part of CI

Appendixes
Wikipedia testing definitions

Testing Terminology (Wikipedia)
Unit test
“..a programmer tests if individual units of source code are fit for use.”
Integration test
“..individual software modules are combined and tested as a group. It occurs after unit testing and before system testing.”
System test / functional test
“..testing conducted on a complete, integrated system to evaluate the system's compliance with its specified requirements.
Regression test
“..seeks to uncover software errors by partially retesting a modified program. The intent of regression testing is to assure that a bug fix has been successfully corrected .. , while providing a general assurance that no other errors were introduced in the process of fixing the original problem.”
Continuous integration
Automated checkout, building and testing of code from source control
Source : Wikipedia

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Unit Tests And Automated Testing

by Lee Englestone on Apr 11, 2010

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Unit Tests And Automated Testing — Presentation Transcript