unit testing
TRANSCRIPT
Unit Testing이규원
www.facebook.com/gyuwon.yi
“Know the rules well, so you can break them effectively.”- Dalai Lama XIV
Automated Testing
Software Regression
“A software bug which makes a feature stop functioning as intended after a certain event”
- Wikipedia
R1 R2 R3 R4
SoftwareFeatures
Costs
Manual(Quality Assurance) Automated
>
Reliability
Manual(Quality Assurance) Automated
<
Arrange
ActAssert
Cleanup
DEMOAutomated UI Testing
Continuous Integration
“Many, including me, consider that CI without testing is not CI at all.”
- The Architecture Journal, January 2008 by Munjal Budhabhatti
Continuous Build
Continuous Integration
Automated Testing
Unit Tests
Horizontal Separation
Layer D
Layer C
Layer B
Layer A
Functional Testing(Vertical Separation)
Syste
m U
nd
er Te
st
Layer D
Layer C
Layer B
Layer A Syste
m U
nd
er Te
stLayer D
Layer C
Layer B
Layer A Syste
m U
nd
er Te
st
Layer D
Layer C
Layer B
Layer A
Function 1 Function 2 Function 3
*Integration Testing
Layer D
Layer C
Layer B
Layer A Syste
m U
nd
er Te
stSystem Under Test
System Under Test
Unit Testing
Layer D
Layer C
Layer B
Layer A System Under Test
System Under Test
System Under Test
System Under Test
Unit Testing
• Fast• Reliable• Isolate failures
Test Doubles
Layer D
Layer C
Test Double for Layer B
Layer A
System Under Test
Inversion of Control
“Don't call us, we'll call you.”
Dependency Inversion
A Layer C depends on a Layer B
A Layer C creates a Layer BA Layer C requests a Layer B
Constructor Injection
public class LayerC
{
private LayerB _layerB;
public LayerC()
{
_layerB = new LayerB();
}
}
public class LayerC
{
private LayerB _layerB;
public LayerC(LayerB layerB)
{
_layerB = layerB;
}
}
<< created >>
<< injected >>
*Interface
public interface ILayerB{}
public class LayerB : ILayerB{}
public class LayerC{ private ILayerB _layerB;
public LayerC(ILayerB layerB) { _layerB = layerB; }}
Test Double
The replacement of a real depended-on componentfor testing purposes
Test Doubles
Dummy
Stubs
Spies
Mocks
Fake
Passed but never used
Provide canned answers
Record information
Verify expectationsHave working
implementations but not suitable for production
DEMOStubs and Mocks
Myth Busting for
Test-Driven Development
Automated testing
TDD
Automated testing with high coverage
TDD
Writing the tests first
TDD
?
Test-Driven Development
Test-Driven Development
Test
Development
TESTS
MAKETH
CODE
Red
GreenRefactor
Write production code
If the test fails
If all tests
succeed
Clean up code
Write a test
yes
yes
no
no
repeat
DEMOTest-Driven Development