SEKE 2012 Proceedings - Knowledge Systems Institute

II. BACKGROUND
In this section, we firstly introduce the preliminaries of test
suite reduction and then show the motivation of our approach
by a simple example.
A. Test Suite Reduction
In regression testing, a simple strategy is to use all previous
test cases to test the modified software, however this strategy
is not always feasible. Researchers proposed different effective
approaches to solve this problem [8]. This paper mainly focuses
on the issue of test suite reduction, which was originally
formalized as follows by Harrold et al. [7]:
Given: A test suite TS = {tc 1 ,tc 2 , ··· ,tc m }, a requirement
set R = {r 1 ,r 2 , ··· ,r n } generated by a test adequacy
criteria C, and subsets of TS: T 1 ,T 2 , ··· ,T n , for each associated
with a r i such that any test case tc j ∈ T i can be used
to cover requirement r i .
Problem: To find a subset of T with the minimum cardinality
that covers all the requirements covered by T .
This problem has been demonstrated to be NP-Complete
and we summarize these related work in Section V.
B. Motivating Example
To illustrate the limitation of previous approaches and show
the motivation of our approach, we design a simple example
shown in Table I.
TABLE I
AMOTIVATING EXAMPLE
cases. Here only the test case < 3, 4 > can detect this fault. If
we use existing test suite reduction approaches, such as HGS
[7], we can get a reduced test suite {< 3, 4 >,< 4, 3 >}
or {< 4, 3 >,< 13, 13 >}. In this case, it only has 50%
probability to detect this fault. However, if we further analyze
the code change, we can find that we do not need to reexecute
the test case < 4, 3 > since this test case do not
cover change related statements (Lines 5-7). Therefore we can
remove this test case and then perform a test suite reduction
on {< 3, 4 >,< 13, 13 >}. Finally we can choose the test
case < 3, 4 > and this test case can detect the fault in the
modified function. Meanwhile the size of reduced test suite is
decreased from 2to1.
III. CATESR APPROACH
In this section, we firstly introduce the framework of our
CATESR approach and then introduce the implementation
detail.
A. The Framework of CATESR approach
We use Figure 1 to show the framework of CATESR approach.
In particular, CATESR takes two consecutive versions
of source code and coverage information of test cases on i-
th version as its input, and produces a reduced test suite to
(i +1)-th version as its output.
Program Segments
Test Cases
bool TestAndSubtract(m, n) < 3, 4 > < 4, 3 > < 13, 13 >
1: if (m