Analysis and Testing of Ajax-based Single-page Web Applications

Research Question 2
Is it possible to support the migration process (Ajaxification) of multipage
web applications to single-page Ajax interfaces? Can reverse engineering
techniques help in automating this process?
Our hypothesis is that reverse engineering (Chikofsky and Cross II, 1990)
techniques can assist us in reconstructing abstract models of the source application,
by automating (Arnold, 1993) all or parts of the process. Since the
user interface interaction models of the source (page-sequence) and the target
(single-page with UI components, see Chapter 2) systems are substantially
different, user interface reverse engineering (Stroulia et al., 2003) will play an
important role in our quest. Automatically reconstructing an abstract user
interface model of the source multi-page web application is a first, but also a
key step in the migration process.
1.3.3 Analysis and Testing
Our final main question deals with the dependability (Sommerville, 2007)
of Ajax applications. In principle, we are interested in appropriate ways to
analyze and test Ajax systems.
For traditional software, analysis and testing is still largely ad hoc
(Bertolino, 2007) and already a notoriously time-consuming and expensive
process (Beizer, 1990). Classical web applications present even more challenges
(Di Lucca and Fasolino, 2006; Andrews et al., 2005) due to their distributed,
heterogeneous nature. In addition, web applications have the ability
to dynamically generate different UIs in response to user inputs and server
state (Andrews et al., 2005).
The highly dynamic nature of Ajax user interfaces and their client/server
delta communication adds an extra level of complexity to the classical web
analysis and testing challenges. Therefore, we formulate our third main question
as:
Research Question 3
What are the challenges for analyzing and testing Ajax applications in
an automatic approach?
which, in turn, is composed of three sub-questions focusing on data delivery
performance, automatic crawling, and user interface testing.
Performance Testing
One of the challenges related to client/server interactions is to ensure data
coherence, i.e., ensuring that the data (state changes) on the server and the
client are synchronized. The hypothesis is that a push-based implementation
offers a higher degree of data coherence when compared to a pull-based one.
But at the same time, it is generally believed that a push-based solution that
keeps open connections for all clients causes scalability problems on the web.
16 1.3. Challenges and Research Questions