Expertiza_Wiki - User contributions [en]

CSC/ECE 517 Fall 2009/wiki1a 1 103

2009-09-12T21:02:16Z

Hwang7: /* Prerequisites */

''' Writing Effective Junit Test Cases '''

This article introduces the best practice a developer should follow in writing ''JUnit'' test cases for Java programming.

== Prerequisites ==

Readers are assumed to be familiar with the following terms/names and their concepts:

[http://en.wikipedia.org/wiki/Unit_testing Unit Testing] - A verification process run by a developer on the smallest testable parts of an application.

[http://en.wikipedia.org/wiki/Test_case Test case] - A process generates a set of conditions and variables by which a developer can tell if a piece of software works correctly.

[http://en.wikipedia.org/wiki/JUnit JUnit] - A unit testing framework for programming in Java.

== Criteria For Effective Unit Testing ==

* Design - It's "Hard to design testable code". "However, testable code often is better designed" [http://bradwilson.typepad.com/presentations/effective-unit-testing.pdf [1]]
* Documentation - Good documentation could prevent oversight, increase transparency, and facilitate knowledge transfer in the future.[http://www.exforsys.com/tutorials/testing/unit-testing.html [2]]
* Good coverage,
: What should be covered in each run of the test:
# UI - All screen elements, spelling, fonts, and sizes of all the “labels” or text. May not be applicable to JUnit since automation may be improbable here.
# Every line of code should at least be executed once.
# Every condition in case of “conditional statements” should be met at least once.
# Every path of all possible ones should be gone through at least once.
# Boundaries - The input parameters should be tested with conditions at the lower and/or upper limits such as too large or too small. Overflow condition should also be tested.
# Every error message/exception handling should be tested
# All validations are being performed, correctly.
# All possible setup configurations should be tested.
* Avoid redundant tests which may give wrong impression of the scale of the bugs and fixes.
* Easy for automation, which should be implied by JUnit.

== Cases Specific to JUnit Test Cases ==
In theory, there shouldn't be anything special regarding to effective unit testing in JUnit compared to any other testing framework. A couple of good resources for designing tests specific in JUnit is the [http://junit.sourceforge.net/doc/faq/faq.htm JUnit FAQ], and the book "Pragmatic Unit Testing in Java with JUnit".
*A simple test
: Create a class:
<pre>

package myPackageToBeTested;
import org.junit.*;
import static org.junit.Assert.*;
import java.util.*;
public class SimpleTest {

//a test method (annotated with @Test) using asserts:
@Test
public void test1plus1() {
assertEquals("1+1=2", 2, 1+1);
}
}

</pre>
* A test suite
: Add a suite() method to the above ''simple test'' example to include all of your test methods:
<pre>

...
public static junit.framework.Test suite() {
return new junit.framework.JUnit4TestAdapter(SimpleTest.class);
}
...

</pre>
* A test template
: This sample test template contains setUp() and tearDown() methods to initialize and release the object(s) being tested
<pre>

import org.junit.*;
import static org.junit.Assert.*;

public class TemplateTest {

// Sets up the test fixture.
@Before
public void setUp() {

}

//Tears down the test fixture.
@After
public void tearDown() {
}

//a test method (annotated with @Test) using asserts:
@Test
public void test1plus1() {
assertEquals("1+1=2", 2, 1+1);
}

public static junit.framework.Test suite() {
return new junit.framework.JUnit4TestAdapter(TemplateTest.class);
}
}

</pre>

== References ==
# [http://bradwilson.typepad.com/presentations/effective-unit-testing.pdf effective unit testing]
# [http://www.exforsys.com/tutorials/testing/unit-testing.html Unit Testing: Why? What? & How?]
# [http://junit.sourceforge.net/doc/faq/faq.htm JUnit FAQ]
# White Box Testing Techniques - NCSU:CSC 510 Software Engineering (Lecture 8)
# Pragmatic Unit Testing in Java with JUnit (ISBN:9780974514017)

CSC/ECE 517 Fall 2009/wiki1a 1 103

2009-09-12T21:02:04Z

Hwang7: /* Prerequisites */

''' Writing Effective Junit Test Cases '''

This article introduces the best practice a developer should follow in writing ''JUnit'' test cases for Java programming.

== Prerequisites ==

Readers are assumed to be familiar with the following terms/names and their conceptdsc:

[http://en.wikipedia.org/wiki/Unit_testing Unit Testing] - A verification process run by a developer on the smallest testable parts of an application.

[http://en.wikipedia.org/wiki/Test_case Test case] - A process generates a set of conditions and variables by which a developer can tell if a piece of software works correctly.

[http://en.wikipedia.org/wiki/JUnit JUnit] - A unit testing framework for programming in Java.

== Criteria For Effective Unit Testing ==

* Design - It's "Hard to design testable code". "However, testable code often is better designed" [http://bradwilson.typepad.com/presentations/effective-unit-testing.pdf [1]]
* Documentation - Good documentation could prevent oversight, increase transparency, and facilitate knowledge transfer in the future.[http://www.exforsys.com/tutorials/testing/unit-testing.html [2]]
* Good coverage,
: What should be covered in each run of the test:
# UI - All screen elements, spelling, fonts, and sizes of all the “labels” or text. May not be applicable to JUnit since automation may be improbable here.
# Every line of code should at least be executed once.
# Every condition in case of “conditional statements” should be met at least once.
# Every path of all possible ones should be gone through at least once.
# Boundaries - The input parameters should be tested with conditions at the lower and/or upper limits such as too large or too small. Overflow condition should also be tested.
# Every error message/exception handling should be tested
# All validations are being performed, correctly.
# All possible setup configurations should be tested.
* Avoid redundant tests which may give wrong impression of the scale of the bugs and fixes.
* Easy for automation, which should be implied by JUnit.

== Cases Specific to JUnit Test Cases ==
In theory, there shouldn't be anything special regarding to effective unit testing in JUnit compared to any other testing framework. A couple of good resources for designing tests specific in JUnit is the [http://junit.sourceforge.net/doc/faq/faq.htm JUnit FAQ], and the book "Pragmatic Unit Testing in Java with JUnit".
*A simple test
: Create a class:
<pre>

package myPackageToBeTested;
import org.junit.*;
import static org.junit.Assert.*;
import java.util.*;
public class SimpleTest {

//a test method (annotated with @Test) using asserts:
@Test
public void test1plus1() {
assertEquals("1+1=2", 2, 1+1);
}
}

</pre>
* A test suite
: Add a suite() method to the above ''simple test'' example to include all of your test methods:
<pre>

...
public static junit.framework.Test suite() {
return new junit.framework.JUnit4TestAdapter(SimpleTest.class);
}
...

</pre>
* A test template
: This sample test template contains setUp() and tearDown() methods to initialize and release the object(s) being tested
<pre>

import org.junit.*;
import static org.junit.Assert.*;

public class TemplateTest {

// Sets up the test fixture.
@Before
public void setUp() {

}

//Tears down the test fixture.
@After
public void tearDown() {
}

//a test method (annotated with @Test) using asserts:
@Test
public void test1plus1() {
assertEquals("1+1=2", 2, 1+1);
}

public static junit.framework.Test suite() {
return new junit.framework.JUnit4TestAdapter(TemplateTest.class);
}
}

</pre>

== References ==
# [http://bradwilson.typepad.com/presentations/effective-unit-testing.pdf effective unit testing]
# [http://www.exforsys.com/tutorials/testing/unit-testing.html Unit Testing: Why? What? & How?]
# [http://junit.sourceforge.net/doc/faq/faq.htm JUnit FAQ]
# White Box Testing Techniques - NCSU:CSC 510 Software Engineering (Lecture 8)
# Pragmatic Unit Testing in Java with JUnit (ISBN:9780974514017)