java unit testing through testng

1. TestNG
Testing code as you write it
Haritha K

2. What is TestNG
A testing framework designed to simplify a
broad range of development testing needs.
• Unit testing (testing a class in isolation of the
others)
• Integration testing (testing entire systems
made of several classes, several packages
and even several external frameworks, such
as application servers).

3. What is TestNG?
• Automated testing framework
• NG = Next Generation
• Similar to JUnit (especially JUnit 4)
• Not a JUnit extension (but inspired by JUnit)
• Designed to be better than JUnit, especially
when testing integrated classes
• Created by Dr. Cédric Beust (of Google)
• Open source (http://testng.org)

4. Installing in eclipse
• The latest version of TestNG can be downloaded from
http://search.maven.org/
• In Eclipse, Select Help / Software updates / Find and Install.
• Search for new features to install.
• New remote site.
• For Eclipse 3.4 and above, enter http://beust.com/eclipse.
• For Eclipse 3.3 and below, enter http://beust.com/eclipse1.
• Make sure the check box next to URL is checked and
click Next.
• Eclipse will then guide you through the process and restart
eclipse.

5. Basic Three steps
• Write the business logic of your test and
insert TestNG Annotations in your code.
• Add the information about your test (e.g. the
class name, the groups you wish to run,
etc...) in a testng.xml file.
• Run TestNG.

6. Keywords
• A suite is represented by one XML file. It can contain
one or more tests and is defined by the <suite> tag.
• A test is represented by <test> and can contain one
or more TestNG classes.
• A TestNG class is a Java class that contains at least
one TestNG annotation. It is represented by
the <class> tag and can contain one or more test
methods.
• A test method is a Java method annotated
by @Test in your source.

7. Possible configurations in xml file
• Class names
• Package names ( will execute all test classes)
• Groups and methods (include/exclude)
• run the tests in parallel, how many threads to use
• TestNG will run your tests in the order they are found
in the XML file. If you want the classes and methods
listed in this file to be run in an unpredictable order,
set the preserve-order attribute to false

8. Annotations
@Test
@BeforeSuite
@AfterSuite
@BeforeTest
@AfterTest
@BeforeGroups
@AfterGroups
@BeforeClass
@AfterClass
@BeforeMethod
@AfterMethod
@DataProvider
@Parameters

9. Assertions
• assertEquals
• assertNotEquals
• assertNotNull
• assertNull
• assertSame
• assertNotSame
• assertTrue
• assertFalse
• fail

10. Groups
• Each test method is tagged with any number of groups.
• @Test // no groups
• @Test (groups = “group1”)
• @Test (groups = { “g1”, “g2”, ... })
• A group therefore contains any number of test methods.
• Groups can span classes.
• Groups can also be externally defined (TestNG xml
configuration file).
• A group is identified by a unique string (don’t use white space).
• There are no pre-defined group names.
• E.g., “slow”, “fast”, “gui”, “check-in”, “week-end”
“unit”,“regression”,“integration”,“broken.unknownReason”

11. Groups continued…
• TestNG community suggests hierarchical
names from more general to less. E.g.:
• database.table.CUSTOMER
• alarm.severity.cleared
• Design group names so that you can select
them with prefix patterns.
• Groups complement other features

12. Groups continued…
You can define groups at the class level and then add groups at
the method level
@Test(groups = { “goldenRegression" })
public class All {
@Test(groups = { “regression" )
public void method1() { }
public void method2() { ... }}
In this class, method2() is part of the group “goldenRegression",
which is defined at the class level, while method1() belongs to
both “goldenRegression" and “regression".

13. Exceptions
• Methods can have more than one
exception thrown
@Test(expectedExceptions =
NullPointerException.class)
Or
@Test(expectedExceptions =
{ T1.class, ... })

14. Ignored Test cases
Enable or disable tests
• @Test(enabled = false)
• Add to a group which is excluded
• Exclude in other ways in testng.xml

15. Timeout
• @Test(timeOut = 1000)
• testng.xml <suite|test> time-out attribute
• The test case will be failed if time period is
exceeded

16. Dependencies
Sometimes, you need your test methods to
be invoked in a certain order
• To make sure a certain number of test
methods have completed and succeeded
before running more test methods.
• To initialize your tests while wanting this
initialization methods to be test methods as
well.

17. Dependency continued
• fail fast:
• run Selenium tests only if application was deployed properly,
• run full system tests only if smoke tests passed,
• logical dependencies between tests:
• execute shouldDeleteUserFromDatabase test only
ifshouldAddUserToDatabase worked
• Fail fast means that the feedback will be much quicker in case
of failed tests.
Logical dependencies gives you a much more realistic error
information - you learn that 1 tests has failed and 99 has been
skipped, which is much easier to fix than the information about
100 failed tests (OMG! what’s going on!? All tests failed)

18. Parameterized tests
• In general, it is a good practice, to test your
code with different sets of parameters:
• expected values: sqrt(4), sqrt(9),
• boundary values: sqrt(0),
• strange/unexpected values: sqrt(-1), sqrt(3)

19. Parameterized Tests continued
• Parameterized tests are very simple with
TestNG.
• You can have as many data providers in one
class as you wish. You can reuse them (call
them from other classes), and you can make
them "lazy", so each set of parameters is
created when required.

20. Parameterized Tests continued
@Parameters({ "datasource", "jdbcDriver" })
@BeforeMethod public void
beforeTest(String ds, String driver)
{ m_dataSource = ...; m_jdbcDriver = driver; }
@DataProvider(name = "test1")
public Iterator<Object[]> createData()
{ return new MyIterator(DATA);}

21. References
• http://testng.org/doc/index.html
• http://testng.org/doc/documentation-main.html
• http://testng.org/testng-1.0.dtd.php
• http://testng.org/javadoc/

22. Thank you