Date post: | 29-Nov-2014 |
Category: |
Technology |
Upload: | david-odowd |
View: | 2,017 times |
Download: | 4 times |
Model-based Testing
Introduction and Hands-on session
Stefan EkmanDublin, 2011-01-27
Model Based TestingWhat is Model-based Testing?
What is MBT?
Wikipedia:
“Model-based testing is software testing in which test
cases are derived in whole or in part from a model that
describes some (usually functional) aspects of the system
under test (SUT).”
Advantages
• Model-based testing is easy to understand from both the business and developer communities
• Model-based testing separates (business-) logic from testing code
• Model-based testing increases the test coverage with the same effort as “Classic” test automation
• Model-based testing is the fastest way to get use of automated test
Advantages
• Model-based testing enables us to switch testing tool if needed or support multiple platforms using the same model
• Model-based testing focuses on requirement coverage, not how many test cases you executed last week etc.
• Model-based testing proved to positively affect the maintenance problem, the nemesis of all test automation.
The ModelModelling your tests
Tools / Environment
.GraphML
Model with yEd
GraphWalker
MBT engine
Selenium
Java or SOAP
QTP
Via SOAP
Hudson
Build system
Code behind
public void e_Nav_GoogleImages()
{
log.info("Edge: e_Nav_GoogleImages");
selenium.click(“link=Images");
selenium.waitForPageToLoad(30000);
}
Modelling
What should the model represent?
I suggest that you start with the model representing the end usage/user functionality of the system. That will usually resemble your traditional functional test case approach. There are several other approaches for you to explore later in you new MBT career…
Modelling
To what level do we model?
Modelling
Who creates the model?
• Start out yourself to begin with• Present the model – show it to SME’s and
developers for input• If the system is non-existing, you probably would
consider user stories, product backlog items, use-cases or the equivalent requirement's information.
Modelling
During this process you will collect the first benefits of working with MBT!
GraphWalker
GraphWalker is a tool for generating offline and online test sequences from Finite State Machines and Extended Finite State Machines.
http://www.graphwalker.org/
• Lightweight MBT – No UML• No exit/stop points• Online• Event-driven
GraphWalker is an Open Source MBT engine created by Kristian Karl and are stable and used in large IT testing environment.
GraphWalker - Stop Criteria's
• REACHED_EDGE• REACHED_VERTEX• EDGE_COVERAGE• VERTEX_COVERAGE• TEST_LENGTH• TEST_DURATION• REACHED_REQUIREMENT• REQUIEMENT_COVERAGE• NEVER
GraphWalker – XML configuration
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE MBTINIT SYSTEM "mbt_setup.dtd" ><MBTINIT EXECUTOR="java:com.paddypower.mbt.BetPlacementRegression" EXTENDED="true"
GUI=“true"> <MODEL PATH="model/BetPlacementRegression.graphml"/> <CLASS PATH="Java\PPautomation\bin"/> <CLASS PATH=".\servlet-2.3.jar"/> <CLASS PATH="selenium\selenium-java-client-driver.jar"/> <CLASS PATH="selenium\selenium-server-2.0a6.jar"/><SCRIPT>
PortNumber = 5555; DBconnectionString =
"jdbc:informix-sqli://10.10.10.10/db:informixserver=testdb1;user=user;password=12345";MAX_SELECTIONS = 10;
</SCRIPT> <GENERATOR TYPE="RANDOM"> <CONDITION TYPE="REACHED_VERTEX" VALUE="v_Done"/> </GENERATOR></MBTINIT>
GraphWalker - The Walks
• RANDOM• A_STAR
Will try to generate the shortest possible test
sequence through a model with given stop
condition. The algorithm only works well on
smaller models.
• SHORTEST_NON_OPTIMIZED
GraphWalker - Edge
• An edge is a transition. Could be a click on a button, a timeout, a server API call.
• An edge can have a label, but it is not mandatory.
• The label of an edge will map against a method, function or sub routine during test execution.
• As a rule of thumb, the best practice is to start the name with 'e_'. The reason for this, is that it is easier to recognize the function in the test execution tool, as an edge. For example:e_StartApplicatione_EnterBasicView
• The same name of an edge, can be re-used in the model.
GraphWalker - Vertex
• A vertex is some kind of state that is possible to verify using some kind of oracle.
• A vertex must always have a label.
• The label of a vertex is mapped against a method, function or sub routine during test execution.
• As a rule of thumb, the best practice is to start the name with 'v_'. The reason for this, is that it is easier to recognize the function in the test execution tool, as a vertex. For example:v_ApplicationStartedv_BasicView
• The same name of a vertex, can be re-used in the model.
GraphWalker - Labels
Label [cond. expr.] / Statement1;Statement2;
White spaces not allowed.
Follow the naming convention for the implementing programming
language.
Example:
e_StartApplication
Example:
e_EnterBasicView
GraphWalker - Guards
Label [cond.expr.] / Statement1;Statement2;
Conditional expression that returns a Boolean value.
The guard indicates if the edge is accessible in the current state of the
machine. The language is either Java or JavaScript.
Example:
e_Evaluate [x>0 && y<=10]
Example:
e_Checkout [shoppingBasket.contains("Cerials")]
GraphWalker - Statements
Label [cond.expr.] / Statement1;Statement2;
Any applicable Java or JavaScript statements
Example:
e_Calculate / x=5;y++;
Example:
e_AddCerials / shoppingBasket.add("Cerials");
GraphWalker – Keyword Start
Used by Vertices only.
Each graph must have a start vertex, and that vertex holds this
keyword. There is only one vertex in a graph, holding this keyword.
The Start vertex can only have one out-edge.
If the graph is the main-graph, that edge must have a
label.
If the graph is a sub-graph, that edge cannot have a label.
GraphWalker - REQTAG
Used by Vertices
Used by GraphWalker for keeping track of which
requirements are fulfilled during testing.
In the example above, if v_BookInfomation is passed, it
would mean the requirement with tag UC01 2.2.3 has
passed.
v_BookInfomationREQTAG=UC01 2.2.3
GraphWalker - Weight
Used by Edges only.
Used by MBT during random walks during test sequence generation. It holds a real value between 0 and 1, and represents the probability that a specific edge should be chosen. A value of 0.05, would mean a 5% chance of that edge to be selected during a run.
Note: It only works with the RANDOM generator
v_BookInfomationREQTAG=UC01 2.2.3
e_NavAweight=0.25
e_NavB
GraphWalker – Keyword Blocked
Used by both Vertices and Edges.
A vertex or an edge with the key word BLOCKED, will be
excluded from the model when walked.
v_BookInfomationBLOCKED
Metrics
• Standard test metrics does not apply so well.• Test cases are not meaningful when running online
tests.• MBT tends to drive the requirement work.
GraphWalker – QTP & SOAP
WebService("SoapServicesService").SetTOProperty "WSDL", "http://myComputerName:9090/mbt-services?WSDL"If ( not WebService("SoapServicesService").Reload() )Then Reporter.ReportEvent micFail, "MBT failure", "MBT encountered an error. See the MBT log files for information." ExitTestEnd If
Do until not WebService("SoapServicesService").HasNextStep() action = WebService("SoapServicesService").GetNextStep() If len(action) > 0 Then If not Eval( action ) Then Reporter.ReportEvent micFail, "Script failure", "The script encountered an error when trying to run function: " & action ExitTest End if End IfLoop
Reporter.ReportEvent micDone, "MBT Statistics", WebService("SoapServicesService").GetStatistics()
5 min break..
I am not in the office at the moment. Please send any work to be translated.
Hands on session
1. Setup the environment
2. Create a model
3. Generate code from model
4. Automate with selenium
5. Create XML configuration file for GraphWalker
6. Run the model!
Files
1. Create directory MBT i.e C:\MBT
2. Create directory Models under in the MBT folder
3. Copy GraphWalker and Selenium jar files to the directoryselenium-java-client-driver.jarselenium-server.jargraphwalker-2.5.1-SNAPSHOT-standalone.jar
Model
Visit www.brickor.com/MBT.htm with Firefox
Record with Selenium IDE by clicking on all elements and as well right clicking the result
Switch off recording.
Options > Format > JUnit4 (Java)
Model
Start yEd to create the model
Generate the Java Code
/** * This method implements the {EDGE_VERTEX} '{LABEL}' */public void {LABEL}(){ log.info( "{EDGE_VERTEX}: {LABEL}" ); throw new RuntimeException( "The {EDGE_VERTEX}: {LABEL} is
not implemented yet!" );}
java -jar graphwalker-2.5.1-SNAPSHOT-standalone.jar source -f Models/mbttest.graphml -t java.template.txt > javacode.txt
Eclipse – Create the Java project
Create new Java Project; MbtTest
Create new Java Package; ie.mbt.test
Create new Class; MBTtest
Copy paste the contents of the generated Java code from the model into the created class.
The java code
Include references to Selenium and GraphWalker in your project. Right click on your project and choose Properties. Under Java Build Path choose Libraries and then click Add External JARs.. Choose the two jar files:
graphwalker-2.5.1-SNAPSHOT-standalone.jarselenium-java-client-driver.jar
private HttpCommandProcessor proc = new HttpCommandProcessor("localhost",4444, "*chrome", “http://www.brickor.com/MBT.htm”);
private Selenium selenium = new DefaultSelenium(proc);
private Logger log = Util.setupLogger(MBTtest.class);// import org.apache.log4j.Logger;
// import org.graphwalker.Util;
Writing the Java Code
In e_init we start the selenium object.
selenium.start();selenium.open("http://www.brickor.com/MBT.htm");
Delete the Throw exception!
Update all e_r11, e_r12 etc
selenium.click("Radio1_1");row1 = Integer.parseInt(selenium.getText(“r11"));
Writing the Java Code
Create the utility GetResult
public boolean GetResult() {int rowTotal = row1 + row2 + row3;int calcTotal =
Integer.parseInt(selenium.getText("totalDiv"));
if (rowTotal==calcTotal)return true;
elsereturn false;
}
IMPORTANT!
Compile you class after any changes, CTRL + B
GraphWalker XML
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE MBTINIT SYSTEM "mbt_setup.dtd" ><MBTINIT EXECUTOR="java:ie.mbt.test.MBTtest" EXTENDED="true"> <MODEL PATH="models/MBTTest.graphml"/> <CLASS PATH="MbtTest\bin"/> <CLASS PATH="selenium-java-client-driver.jar"/> <CLASS PATH="selenium-server.jar"/> <GENERATOR TYPE="RANDOM"> <CONDITION TYPE="TEST_LENGTH" VALUE="1000"/> </GENERATOR></MBTINIT>
Selenium Server
java -jar selenium-server.jar
Will start with default settings on port 4444
Start the scripts..
Command line to start GraphWalker with the correct settings:
java -jar graphwalker-2.5.1-SNAPSHOT-standalone.jar gui xml -f MBTTest.xml
Questions?
More info at:
www.graphwalker.org
mbt.tigris.org
http://en.wikipedia.org/wiki/Model-based_testing
Email: [email protected]