how to ensure the web quality using object oriented approach

8/12/2019 How to Ensure the Web Quality Using Object Oriented Approach

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Testing Techniques Used for Web Application and OOSDRizwan Haider [060451]

Rizwan Ali [060452]Bachelor Software Engineering Air University Islamabad, Pakistan

[email protected]

[email protected]

Abstract

Today amount of web application traffic on internet is

increasing day by day; the quality of web application

becomes serious.

The purpose of this document is to discuss testing

techniques of web application system and OOAD system.

In this we go through the different process area used for

testing for both systems, to increase the efficiency,

flexibility of development and quality.

1. Introduction

1.1 Why Testing Important for Web Application

and Object Orient?

Today web applications have become the part of our daily

lives. We are done online as more and more very

important and critical services as bank transaction and tax

declaration using web services. So the quality, reliability

and dependability are important factors because software

bugs and error could block entire businesses and cause

major shame for web services providers.

Web applications are complex and mixed software, basedon several components. Its often written in many

different languages and distributed over the Web placed

on different locations. Thus, testing of Web applications

become a complex task for tester.

Software has become a very important and performs

complex task today, but often invisible part of our lives.

Computers and the internet and telecommunication world

have considerably changed our lives.

For the near future, we will not have a single notation or

process that can cover the mixture of todays development

projects. Projects are too different in their application

domain, size, need for reliability, time-to-market pressure,and the skills and demands of the project participants.

1.2 Main Focus

So the testing of both web based system and OOSD

system are very important. Here we discuss the testing

techniques for functional and non-functional requirements

for both systems. We also answer the important question

testing of web application through object oriented

approach.

1.3 Difference between OO application and web

Application

In desktop interactive applications, the application is

running during the whole relations, and the application

state is held in memory as the application waits for user

input.

In difference, web application page sent a request to webservers. Web server process it, send a response, according

to the request send by the client and stored in database if

need. On the client end all this information is stored in

session data in browser cookies. This creates new

challenges for testing.

Both applications are object oriented or not.

MAIN THRUST

First we discuss the testing techniques of web application

systems and then Object Orient System.

2. Testing of Functional Requirements in

Web Application

The functional requirements follows well-established

methods for testing, we will give flavor almost all the

methods in this report.

Traditional testing methods are used to test functional

requirements, such as unit testing because web application

used Model-View-Controller for data storage.

When testing equivalent to menu paths or dialog box

sequences they can be represented using a Markov model.

2.1 White Box

White-box methods do testing based on the bases of code.

Generate different models on the code in order to create

test cases that cover all possible paths through the

application.

Liu et al. [1] identified some of the following flow graph

which helps us to understand the interactions between

complex pages that cause bugs.
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


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Types of Graphs are defines as:

Control Flow Graphs (CFG) are created to show the

statements, branches and conditions which together define

the flow of control through the code for a distinct

function.

Inter-procedural Control Flow Graphs (ICFG)

represent the control flow through a number of related

functions as they call and pass information with each

other.

Object Flow Graphs (OFG) collect the control flow

graphs (ICFG) for all the function calls on an object

caused by a user action.

Composite Control Flow Graphs (CCFG) are created

from the OFG for the code involved in the interaction

between two pages, containing all the user input, user

commands and state information that is passed between

them.From these CFGs, we can get the data flow in form of

def-use tables which defines variables and their use.

2.2 Black Box

Black-box techniques take an outside, users-point-of view

approach and use no internal knowledge of the code.

Test cases are created using traditional methods, such as

Equivalence Partitioning, where we divide the input

ranges into partitions, and create test cases within each

partition. Using Boundary Value Analysis we write tests

to test the borders between partitions. State transition

testing describes relationships where the state ofapplication changes.Error guessing, where the tester uses

his experience to test for common errors.

Di Lucca, et al. [2] explore the representation of test cases

in the form of a Decision Table, containing

- Input variables consisting of user-entered data in web

forms.

-Input actions consisting of the URL and actions specified

in a GET variables.

- State before test consisting of page attributes, cookies,database contents, etc.

- Expected results containing the correct output.

-Expected output actions that have been run as a

consequence of the request.

- Expected state after test which may have changed in

accordance to the action requested.

2.3 Grey Box

Grey-box techniques combine flavor of white-box and

black-box testing methods, grey box testing an applicationaccording to its specification, design, condition and

requirement, but by relying on information internal to the

application.

[3] One popular method is creating test cases by recording

user session actions and data from real sessions to create

logs. Analyzing the logs will also reveal the most

trafficked areas and hence what areas need the most

testing.

This method relies on the size and quality of the collected

session data - too small a sample means that many parts

of the application may be poorly tested. This method may

not be the most efficient in all cases, for instance in low-

traffic or unemployed applications the time required tocollect test data may be too long.

3.0 Testing of Non-Functional Requirements

in Web Application

Some techniques are specific to test the non-functional

requirements of the web based system.

The main non-functional requirements to test are the four

problem areas compatibility, performance, security and

usability.

3.1 Compatibility

This test checks the compatibility of the browser. Mostly

developers are choice most popular browsers to perform

this test.

The first step ensures the valid use of standards such as

HTML and CSS using markup validation tools. This is

easily automated, and must be applied to the final page

output.

The second is to test on actual web browsers. This testing

must be done manually, as the only possible automation

would be to make screenshot comparisons, and these

would be very prone to error, and have to be updated

manually any time a change is made to the code. The testcases for covering compatibility must include

-Each individual page

-Each possible style sheet

-Execution of all client-side scripting code (such as

JavaScript)


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- Any embedded plug-ins (such as Java, Flash)

The test cases are compiled in to a checklist which is then

run through manually by a tester, at the very least before

each release.

3.2 Performance

Performance depends on these factors:

Request Sent from Client to Server or Client to

Server

This delay is principally defined by the physical distance

to the server from Clint.

The signal propagation delay is called the round-trip time,

or ping time, and can be tested using command-line tools

such as ping. It can depend on many factors, mainly

physical distance, but also connection diffusion and how

many hops there are between the nodes.

Server Waits for Resources to be Free

If there are too many requests in a queue, the server must

wait resources. If you suspect this may be a bottleneck in

your application.

Testing can be done using kernel statistics in your

operating system, such as thewaiting statisticin Linux.

Server Page Generation

Page generation speed depends on the:

Server Processor Code Complexity Efficiency

To perform this test local test platform can be used, which

avoids the delays involved in networking. To cut disk

speeds out of the equation, a RAM disk can be in use

during testing.

Database Disk Reads/Writes

Reads and writes are delayed by the disks rotational

speed. The read heads access speed, and the caching

efficiency of the operating system. A web application can

also have more or less disk usage, and more or lessintelligent disk usage.

The client browser processing and display speed

Complex HTML, JavaScript scripting code and plug-ins

can require real time client-side processing time before

the user actually sees the site on their screen.

A good test platform based on the common hardware

owned by the target group should be used to test client

side performance. This test is depending on the client side

processing.

Web applications should be tested for high user loads.

Performance while under load from a large amount ofusers is easily tested by generating a large amount of page

requests, and measuring the time required to receive a

response.

To create reasonable request models, statistics can be

pulled from real access logs in order to focus traffic on

the most popular pages.

3.3 Security

Security of web application is done by attempting attacks

by malicious users. The most common attacks are easy to

generate automatically are:

Cross-site scripting

SQL injection and Buffer overflows

This can be done by an automatic spider program which

visits all the pages on the site and attempts to develop

them.

3.4 Usability

Usability of a site is totally-dependant on your target

addressees. Beginners will need time to navigate complex

structures than advanced users.

Client target specifications are like Graphical and HTML

Optimizations for Performance, Target DisplayResolution and Target Color Depth.

Ex: Simple Look and Feel (Google.com)

3.0 Testing of Object Orient System

In OO programs that include inheritance, aggregation,

association, template class instantiation, class nesting,

dynamic object creation, polymorphism and dynamic

binding relationships complexity is readily found. So the

complexity of the testing will increase if the class is

depending on to many other classes.

In this section we will discuss different testing techniques

for testing the OO system.

There are generally 4 levels of testing for object

orientated systems depending on approach, consisting of:

1. Method Testing (Unit Testing)

2. Class Testing (Unit Testing/Interclass Testing)

3. Interclass Testing (Integration Testing)

4. System Testing

5. State Base Testing


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4.0 Testing of Web Application through OO

Approach

Here we discuss the OTMW (OO Testing Model for Web

Applications Analysis and Design). OTMW tests Web

software using three different layers of test:

Unit Testing Integration Testing System Testing

The testing performed by using OTMW model is inspired

by the category partition method which is a specific sub-

type of the functional testing method known as

equivalence classes (EC) based testing. The EC

method, for every testing layer (unit, integration, system)

defines subdivisions of the application input domain in

equivalence classes which are used to derive test cases.

OTMW model is used to test an application through a

gray box approach. There are six main steps to perform

unit, integration and system testing to consider structuralinformation using this Model. These steps are the

following:

1. We need to build the OO model for the existingapplication under testing.

2. When the application under test is describedthrough UML class, sequence and state diagrams

class diagram identifies software unit to test.

3. Then perform the unit testing for this testing weuse its state diagram to build its eFCG (graph of

function calls and actions). eFCG use to define

the test cases through the expected unit behavior

shown in this eFCG. Then, we build the stages to

defined set of functional test cases.

4. Then identify the integration order of systemunits needed to test the software components

interactions. In this phase, we use the wTDG

graph, built from UML class diagram. These

graphs are used to extract information about the

components dependencies and use a genetic-

based algorithm that analyzes some coupling

measurements among components in order to

devise the best set of sequences usable to test the

components integration.

5. Then test every cluster identified in the previousstep (a cluster is a group of software units

collaborating among them). In this case cluster is

treating as a big-unit. Then merge eFCGs the

same cluster to define the functional test cases

and then to write scripting code using the XUnit

tools. Then we test the whole integrated cluster.

6. In the last step of OTMW performs wholesystem testing. Using the UML we build a

graphs which contains only high level

information to describes the application as a

graph. This graph composed of nodes and edges.

Nodes representing pages and edges representing

links existing on pages. Using this graph, we

perform some random walks paths to pass

through the graph and to simulate user

navigations using a set of sequences of URLs

randomly generated based on the graph

coverage.

5.0. Conclusion

This paper is presents the test techniques of Web

Application. And which techniques make the web testing

form the OO testing. Today web application and web

services over the internet become the heart of internet. So

the testing of web application is very important.

6.0. References

[1] Chien-Hung Liu David C. Kung Pei Hsia: Object-

Based Data Flow Testing of Web Applications,

IEEE, 2000

[2] Giuseppe A. Di Lucca, Anna Rita Fasolino, Francesco

Faralli, Ugo De Carlini: Testing Web Applications,

IEEE, 2002

[3] Christian, Baron Testing web applications

[4] Marchetto, Trentini "A framework for WebApplications Testing through Object Oriented

approach and XUnit tools"

how to ensure the web quality using object oriented approach

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