TESTING WEB APPLICATIONS INTELLIGENTLY

BASED ON AGENT

Lei Xu and Baowen Xu

Department of Computer Science & Engineering, Southeast University, Nanjing 210096, China

Jiangsu Institute of Software Quality, Nanjing 210096, China

Keywords: Web Application Testing, Capture-Replay, Intelligent Agents

Abstract: Web application testing is concerned with n

umerous and complicated testing objects, methods and

processes. In order to improve the testing efficiency, the automatic and intelligent level of the testing

execution should be enhanced. So combined with the specialties of the Web applications, the necessity and

feasibility of the automatic and intelligent execution of the Web application testing are analyzed firstly;

Then, on the base of the related work, the executing process of the Web application testing is detailedly

described and thoroughly analysed, so as to determine the steps and flows of the testing execution along

with the adopted techniques and tools; next, improve the capture-replay technique and make it fit for the

dynamic characters of Web applications, and adopt the intelligent Agent to realize the monitor,

management and exception-handler of the whole testing execution. Thus, in this way, the process of the

Web application testing can be implemented automatically and intelligently.

1 INTRODUCTION

Web applications can realize the information

sharing in the wide world, so multiple users pay

attention to the new comings and the user number

increased at a rare bat. Thus the testing for these

Web applications must be carried out systemically,

completely and sufficiently, so as to ensure their

qualities and satisfy users’ requirements finally.

However, since Web applications have the

characters such as distributed, dynamic, multi-

platform, interactive and hypermedia, and their

running environments are heterogeneous and

autonomous, it is more difficult to carry out the

testing tasks. So in order to enhance the testing

efficiency and improve the testing effect,

appropriate testing methods and tools are needed,

which are focused on these specialties.

Web application testing is concerned with the

ultiple page contents, testing targets, steps and

methods, and the whole process generally requires a

great deal of manpower and material resources. For

the sake of reducing the testing cost, the automatic

level of the testing process should be improved, i.e.

go along with the testing under the tools’ assistants,

make use of tools to dispose the routine problems of

testing and the testers only monitor the whole

process. At the same time, the related tools must

have a certain degree of intelligence so as to adapt

to the dynamic and evolutive specialties of Web

applications.

At present, researchers pay more and more

tentions to Web testing, propose some methods

and obtain many important results (Gao, J. et al.,

1999),(Kallepalli, C., and Tian, J., 2001),(Kung,

D.C. et al., 2000),(Liu, C.H., 2002),(Ricca, F., and

Tonella, P., 2000),(Warren, P., Boldyreff, C., and

Munro, M., 1999). And we also attempted some

research in the area of Web testing modelling,

performance improvement, and the detailed testing

methods (Xu, L., and Xu, B.W., 2003),(Xu, L. et al.,

2003),(Xu, L. et al., 2003). This paper focuses on

how to realize the Web application testing

automatically and intelligently. So in Section 2, we

introduced the related work so as to explain the

necessity and feasibility of carrying out the Web

application testing automatically and intelligently.

In Section 3, we detailedly described and thoroughly

analyzed the executing process of the Web

application testing, so as to determine the steps and

flows of the testing execution along with the related

contents such as the adopted techniques and tools;

Furthermore, we presented the realization

techniques of the testing process, i.e. improved the

capture-replay technique and made it suitable for the

dynamic characters of Web applications, and

194

Xu L. and Xu B. (2005).

TESTING WEB APPLICATIONS INTELLIGENTLY BASED ON AGENT.

In Proceedings of the Seventh International Conference on Enterprise Information Systems, pages 194-199

DOI: 10.5220/0002540501940199

 SciTePress

adopted the intelligent Agent to realize the monitor,

management and exception-handler of the whole

testing execution. Section 5 is concerned with the

conclusions and the future work.

2 RELATED WORK

Testing Web application is concerned with the

contents of the three aspects, i.e. the running

environment, previous preparing work and the

executing process. Since Web applications are used

by vast users, the testing is usually carried out in the

client-side so as to have more authenticities, and the

testing is also demanded to be executed under all

kinds of typical equipments of client-side. In the

preparing work before testing, testing objects and

testing plans must be determined, which include

generating and selecting the test cases (including the

input and expected output of the testing), and

establishing the testing actions and steps. So in the

executing process of the testing, testers often carry

out many test cases under several typical testing

environment so as to obtain the coverage rate as

high as possible, and they execute the actions due to

the previous determined testing steps, such as the

testing input, function running and results

comparison with the expected outputs.

Manually executing the Web application testing

has high cost and low efficiency. So automatic

testing is needed obviously. However, the

exceptions are often produced in the testing process,

and these errors could exist in the server side,

network transfers or the browser parser.

Furthermore, the presented error messages are very

vague, and this brings great difficulties to the error

diagnosis and exclusion. Thus it is urgent to

improve the intelligent degree of the testing so as to

guarantee the execution of the testing.

On the other hand, since the testers generally

carry out the testing with the rigid steps and the

determinate contents, the whole process is suitable

for the automatic execution. By now, there have

been several testing assistant tools, which are

applied in the performance testing or the regression

testing. Paper (Anupam, V et al, 2000) described the

working process and related techniques of the

capture-replay tools, i.e. firstly capturing the actions

carried out by users in the correlative pages, then

storing them to the appropriate places due to a

certain sequences and contents, and replaying the

steps and contents after the searching and matching

finally. Apparently, this technique can be used to

realize the automatic testing. However, there are

many dynamic-generated pages in the Web

applications and the changes are very frequent in the

pages, so the intelligent degree of the capture-replay

tool also should be enhanced.

The intelligent Agent has its background in the

early work on artificial intelligence (AI) when

researchers concentrated on creating artificial

entities that mimicked human abilities (Hewitt, C.,

1977), and has good attributes such as autonomy,

cooperation and learning (Krulwich, B.,

1997),(Murugesan, S., 1998). So they can operate

on themselves without the manual guidance and can

perform certain tasks on behalf of its users. It could

also interact with other intelligent agents and/or

human in performing its task(s) via some

communication language. A key attribute of an

intelligent Agent is its ability to learn to understand

the user’s preferences and behaviour, to cope with

new situations it may face and to improve its

performance over time. These characters make the

Agent rather fit for the distributed platform such as

the Internet, and the Agent has made effective

progress (Belkin, N.J. and Croft, W.B.,

1992),(Guttman, R.H. et al., 1998),(Wooldridge, J.,

and Jennings, N.R., 1995) in Information Retrieval

(IR), personalization services, and etc. Furthermore,

the technique of the Agent also can be applied to the

intelligent Web application testing (Xu, L. et al.,

2003).

Thus we can combine the capture-replay

technique and the intelligent Agent to the automatic

and intelligent testing for Web applications, i.e.

manage the capture-replay tools by the Agent,

improve the testing effect by the learning function

of the Agent so as to deal with the real changes,

exceptions and faults, and realize the intelligent

search and fuzzy match to fit for the dynamic and

interactive properties of Web applications.

3 TESTING SCHEME FOR WEB

APPLICATION

Executing the Web application testing should

consider the related factors completely, and this

process is divided into three parts: testing input,

testing execution and testing output. As shown in

Figure 1, the input part of the testing is the test cases

that are prepared previously, which includes the

input information, expected output and the detailed

Results

Analysis

Comparison

Measuremen

Test Cases

Input Info

Expected Output

Figure 1: Execution Process of the Web Application Testing

Client-Side

Equipment

Monito

Executo

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test steps; then under a certain client-side

equipment, the testing monitor organizes and

manages the executors to fulfil the testing tasks;

next, output the testing results to the last phase, and

analyze and compare the results with the expected

output, furthermore give metrics and feedbacks to

the Web application.

The precondition of the Web application testing

is the test cases generation and selection, so it is

important to ensure the quality and quantity of the

test cases. The usual steps of generating and

selecting test cases can be described as follows:

(1) In order to obtain the executing sequences

of the testing, the testing requirements and the

structure contents of the Web application are

considered and analyzed in detail, so as to determine

the testing steps and input information such as

variable, parameter name, type and value domain.

(2) For ascertaining the expected output, the

general method is analysing the Web application

and the testing requirements, and running the test

cases several times in advance when the dynamic

scenes are considered, then classifying the results

into different kinds so as to provide references to the

next testing.

(3) Based on the generated test cases, further

work such as the simplification is needed to obtain

the right number of test cases that have the equal

qualities.

The quality of the test cases influences the

testing effects directly, thus testers usually spend

more testing costs during this process of test case

generation. In paper (Xu, L. et al., 2003), we

proposed a test case generating method based on the

combinatorial testing and apply this method to the

Web compatibility testing. In this way, we can cover

more situations with less number of test cases and

obtain higher testing efficiency.

The executing part of testing is constituted of

client-side equipment, monitor and executor.

Among them, the client-side equipment provides the

testing environment, which has a certain degree of

typicality and is more important in the Web

compatibility testing; the monitor is the kernel part

of the testing execution, and it obtains the test cases

directly, controls and organizes the whole testing

tasks, monitors the running status of every executor

and guarantees the load equilibrium and

communication among the executors, and can deal

with certain exceptions, which is carried out by

testers or some intelligent entities; the executor is

the main actor who fulfils the testing tasks, and it

executes the test cases due to certain sequences and

steps heavily and tediously, i.e. based on the testing

steps and input information in the test cases, the

executor visits the Websites or pages under test,

fulfils the prescribed testing actions, then outputs

the testing results to the next phase. Furthermore,

the expected outputs in the test cases are also

delivered to the next phase by the monitor, so as to

process the results comparison and feedback.

The usual testing process and steps are described

in the above, and the executing efficiency is the

main problem to solve. As shown in the before, the

testing for Web applications has huge scale and

tedious tasks, and it is impossible to execute the

testing only by manual work. So the testing must be

fulfilled under the assistant tools to realize the

automatic or semi-automatic testing; and at the same

time, the intelligent level of the related tools also

should be improved so as to deal with the

exceptions.

After obtaining the testing results, the

comparison with the expected results is demanded

so as to judge whether pass the testing. Quantitative

analysis is still needed to the testing results. Then

based on the existed criterions and standards, the

Web application metrics can be established and

adjusted so as to evaluate the quality of the Web

application and the efficiency of the testing.

Furthermore, the modification and maintenance to

the Web application are required due to the testing

results, i.e. feedback the testing results to the Web

application itself, and further improve the system’s

quality, performance, reliability, usability and

safety.

4 REALIZATION TECHNIQUES

Based on the previous work, in order to realize the

automatic and intelligent Web application testing,

adjustment and optimisation are also needed to the

capture-replay technique and the intelligent Agent,

so as to be seasoned with the interactive, dynamic

and frequent-change properties of Web applications,

and finally complete the testing tasks successfully.

4.1 Obtaining Testing Behaviours

In general, the capture-replay technique is used to

realize the automatic Web application testing.

Therefore, we must capture the testing behaviours of

testers firstly, then record these steps and actions by

Script language, and finally replay the Script to

fulfil the automatic testing. In our method, we set an

Agent in the test side, and capture the contents such

as executing actions and input information of the

testers by the recording, learning and analysis

functions of the Agent. Since Agent has the ability

of self-learning, we can capture more precise testing

behaviours by the Agent’s coordinate and analysis.

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Figure 2 shows the inner structure of the test-

side Agent, which is consisted of three portions, i.e.

the recorder (Krulwich, B., 1997), the analyzer and

the repository. This Agent runs at the executing

circumstance of the testing, and the flow steps can

be described as follows:

(1) When the testers begin their testing actions,

the recorder inside the Agent starts executing its

tasks at the same time, and it captures and records

all the behaviours that have taken place in sequence,

such as the hyperlink-hitting and the form

submission, so we can capture testers’ executing

sequences and all the testing actions in focus, and

gain a full executing process of testing at last.

(2) After a period of time (set to the

requirement), the analyzer in the Agent carries out

the classification and coordinate work to the

contents inside the recorder, i.e. classifying the

testing actions due to the different testing targets

(for example, in the form function testing, testers

must prepare the test cases that have all kinds of

selected-values; and in the Web performance testing,

multiple virtue users are needed to visit the server

concurrently).

(3) In this way, the testing behaviours of the

testers are captured, which are focused on different

testing targets. And such knowledge is stored in the

repository for the coming usages.

Furthermore, the above process can be refreshed

due to the real instances of the tester’s executing

actions, so as to insure the contents in the repository

have the precision and the freshness.

Since the tasks of Web application testing are

very heavy and tedious, it is impossible to capture

all the testing scenes; additionally, the dynamic

generated pages and the frequent changes make the

captured testing scenes unable directly use or never

be applicable. However, the captured testing

behaviours obtained in our method have better

operability owing to the test-side Agent, for by the

learning and analysis of the Agent, we can present

the corresponding testing process due to the

different testing targets, thus they have wider

adaptabilities. Furthermore, since the testing process

is recorded very detailedly, we have the specific

guidance abilities on the testing details.

4.2 Executing Testing Automatically

Tes

-Side A

Repository

After capturing the testing behaviours through the

intelligent Agent, the automatic replay for the test

can also be carried out by Agent, i.e. choosing some

intelligent Agents as the testing executor, and

substituting the testers to fulfil the testing tasks, so

as to improve the testing efficiency evidently. Thus

the capture-replay task can be implemented by the

test-side Agent and the test-execution Agent

respectively, but the two kinds of Agents have some

differences in the inner structure and the functional

realization.

Recorde

Analyze

The workflow of the test-execution Agent is

shown in Figure 3, and this kind of Agent performs

the testing tasks under the control of the testing

monitor. The working process of this Agent can be

described as follows: firstly, based on the type of the

testing target, choose the corresponding testing

scene in the test-side Agent’s repository; then

determine the testing steps and executing

behaviours, combined with the input data that are

provided by the test cases; next, the test-execution

Agent visits the Web pages under testing and

implement the recorded actions such as hitting

hyperlinks or filling in the form information; finally,

output the testing results to the testing monitor, by

which we can enter the next testing phase.

When the test-execution Agent replays the

testing behaviours, some problems may take place

such as unable using the recorded actions, since

there are dynamic generated pages and often-

changed pages in the Web applications. In order to

solve these problems, fuzzy match and intelligent

identification techniques are fetched so as to suit for

the properties of Web application. Namely, as the

different pages are concerned, which are generated

dynamically by the same submitted form, since they

are generated from the common template, they have

the similarities in their structures, thus the content

differences can be discovered quickly by the fuzzy

match; and by the intelligent identification to the

page elements, the Agent can find the changes of the

pages under testing, thus it can adjust the testing

scheme accordingly.

Figure 2: Inner Structure of Test-Side Agent

Test-Side

Agent

Testing

Scenes

Test

Execution Agent

Web

Application

Testing Steps

--- ---

Testing Monito

Tes

Cases

Tes

Results

Figure 3: Workflow of Test-Execution Agent.

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4.3 Monitoring the Testing Process

The testing monitor takes charge of the control and

harmony with the whole testing tasks, and is

generally taken on by testers or some intelligent

entities. In order to improve the intelligent degree of

the testing, liberate the testers drastically and

facilitate the communication and interaction with

the test-execution Agent, we also select the

intelligent Agent as the testing monitor so as to own

the consistent in the presentation and contact.

Combined with Figure 1 and Figure 3, we know

the testing monitor is the hinge of the whole testing

process, which is associated with the input and

output of the testing, and also monitors the running

states of each test-execution Agent. The workflow

of the test-monitor Agent is described as follows:

(1) After the test cases are send to the test-

monitor Agent as the input information, the Agent

estimates the scale of the testing tasks so as to

determine the needed number of the test-execution

Agents, and divides the tasks into several cells for

each test-execution Agent.

(2) Based on the running states of each test-

execution Agent, the test-monitor Agent carries out

the real-time management and control, so as to

ensure the load equilibriums and the collaborative

communications among the test-execution Agents.

(3) When the exceptions come forth during the

testing process, the test-monitor Agent adopts some

schemes to deal with these problems, excluding the

faults and eliminating the influences in time.

The realization of the above functions requires a

great deal of trainings for the test-monitor Agent

beforehand, thus generate some disciplinarians and

regulations, and store them into the repository of the

test-monitor Agent; at the same time, utilizing the

self-learning property of the Agent, it can improve

the intelligent degree of itself ceaselessly until it has

the ability to solve the exceptions independently and

availably.

5 CONCLUSIONS AND FUTURE

DIRECTIONS

Web applications develop very rapidly, but their

properties, such as distributed, dynamic, multi-

platform and interactive along with the

heterogeneous and autonomous running

environments, make it much difficult to carry out

the testing. And the testing process usually needs a

great deal of testing cost, however, the testing

efficiency is not high. So it is urgent to adopt some

testing assistant tools to improve the automatic level

of the testing process; at the same time, it is also

demanded that these tools should have certain

degree of intelligence to fit for Web applications’

dynamic and evolving characters.

Based on the previous work, this paper

established an executing scheme for the Web

application testing, and the realizing techniques

have certain degree of automatization and

intelligence. By introducing the related work, we

explained the necessity and feasibility of carrying

out the Web application testing automatically and

intelligently. Then, the executing process of the

Web application testing were detailedly described

and thoroughly analyzed, and in this way, we

determined the steps and flows of the testing

execution along with the related contents such as the

adopted techniques and tools. Next part was

concerned with the realization techniques. In this

section, we improved the capture-replay technique

and made it suitable for the dynamic characters of

Web applications, and adopted the intelligent Agent

to realize the precise testing behaviours, correct

replaying, and the monitor, management and

exception-handler of the whole process for the Web

application testing.

Future directions are focused on the research of

the realizing techniques of the testing process for

Web applications. Since the testing process is

divided into three phrases, i.e. the prophase

preparation, testing execution, and comparing

testing results, and the relationships among them are

close and influencing each other. So it is urgent to

deeply research the details of each separate phase

firstly, then integrate them into a related whole, so

as to optimize and consummate the testing process

and equip them with better pertinence and

adaptability. When the realizing details are referred,

we should pay more attention to the developing

trends of Web applications, and furthermore select

some valuable assistant tools, mathematic theories

and realizing techniques to the testing process of

Web applications, so as to further improve the

automatic and intelligent level of the testing. And

the future work still includes the research and

development of the related tools.

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