Frank Xu, Ph.D. Gannon University Mining Decision Trees as Test Oracles for Java Bytecode Xu, W., Ding, T., Wang, H., Xu. D., Mining Test Oracles for Test Inputs Generated from Java Bytecode, Proc. of the 37th Annual International Computer Software & Applications Conference, pp , Kyoto, Japan, July 2013 Mining Decision Trees as Test Oracles for Java Bytecode (Extended version of conference paper), Accepted by Journal of Systems and Software
Bio – Frank Xu Education Ph.D. in Software Engineering North Dakota State University M.S. in Computer Science Towson University B.S. in Computer ScienceSoutheast Missouri State University Working Experience GE Transportation, present, Consultant of Locomotive Remote Diagnostics Service Center Gannon University, present, Assistant Professor of Software Engineering, Director of Keystone Software Development Institute, University VA –Wise, , Assistant Professor of Software Engineering Swanson Health Products, 2005 ~ 2007, Sr. Programmer Analyst Volt Information Science Inc., 2004 ~ 2005, Software Engineer
Teaching Source: Student Evaluation Report
Research Source: Google scholar:
Mining Decision Trees as Test Oracles I NTRODUCTION R UNNING E XAMPLE T EST I NPUT G ENERATION M ODEL M INER E MPIRICAL S TUDY R ELATED W ORK C ONCLUSIONS
I NTRODUCTION
Exercise Implementing a method to solve Triangle problem
What is Triangle Problem?
How to test Triangle? String getTriangleType (int a, int b, int c){ if((a<b+c) && (b<a+c) && (c<a+b)){ if (a==b && b==c) return “Equilateral ”; else if (a!=b && a!=c &&b!=c) return “Scalene ”; else return “Isosceles” ; } else return “NotATriangle “; } String getTriangleType (int a, int b, int c){ if((a<b+c) && (b<a+c) && (c<a+b)){ if (a==b && b==c) return “Equilateral ”; else if (a!=b && a!=c &&b!=c) return “Scalene ”; else return “Isosceles” ; } else return “NotATriangle “; }
Control Flow Diagram
S UMMARY : T EST T RIANGLE S TEPS Source Code Control Flow Diagram Paths (based on coverage) assertEquals(“Isosceles ”, triangle.getTriangleType(7,7,7)) Junit Test cases assertEquals(“Isosceles ”, triangle.getTriangleType(6,6,8)) ….. Step 1 Step 2 Step 3
How to generate testing inputs automatically? E.g.,(7,7,7), (6,6,8)…. How to find expected results automatically for each inputs? Known as test oracle issue E.g., Equilateral, Isosceles... A UTO -G ENERATE T EST C ASES IS C HALLENGING assertEquals (“Equilateral”, triangle.getTriType(7,7,7)) assertEquals (“Isosceles ”, triangle.getTriType(6,6,8)) ….. ?
O UR A PPROACH TO S OLVE C HALLENGES Rule-based search method to generate inputs Seed value adjust seed values based on rules (5,7,8) for Isosceles Adjust input values a==b (7,7,8) (5,5,8) Using heuristic model for test oracle (expected results ) A new data mining approach to building a heuristic behavioral model (in the form of decision tree) A heuristic behavioral model represents the estimated expected results
Test Oracle Overview
R EVISIT : T RIANGLE P ROBLEM
Java is Complex Statement contains comparison and expression a <b+c (Java) Condition (a<b+c) && (b<a+c) && (c<a+b)
J AVA S IMPLER V ERSION Simplify Statement a <b+c (Java) [1] $i3=i1+i2 and [2] i0>=$i3 (Jimple) Simplify condition (a<b+c) && (b<a+c) && (c<a+b) (Java) Jimple if (a<b+c) { if (b<a+c) { if(c<a+b) … }}}
IDPath 1 2 3,,,..,,, IDabc ………… … Generate inputs Mine test oracle (7,7,7) Equilateral Path generation Generate CFG
H OW TO G ENERATE T EST I NPUTS IDabc … ………… … IDPath 1 2 3,,,
Search an input that make predicate [5]:i0>=$i3 to true a>=b+c (NotATriangle) Challenge: backtracking $i3 to input variables Recall $i3=i1+i2 Solution: Predicate Tree Recall Property 1 a>=b+c
Apply Rules to a Predicate Tree for Generating Test Inputs For a given seed value, we adjust the value to guide the execution path based on rules
IDPredicateExpected Evaluation Outcomes Advising Rules 1. i0 > i1(i0 > i1) = true(i0 ↑, i1) (i0, i1 ↓ ) 1. (i0 > i1) = false(i0 ↓,b) (i0, i1 ↑ ) 1. i0 == i1(i0==i1) = true(i0 ↓ D, i1)( i0, i1 ↑ D) 1. (i0== i1)= false(i0 ↑,i1) (i0, i1 ↑ ) (i0 ↓,i1) (i0, i1 ↓ ) 1. i2 = i0 + i1i2 ↑ (i0 ↑, i1) (i0, i1 ↑ ) 1. i2 ↓ (i0 ↓, i1) (i0, i1 ↓ ) 1. i2 = i0 - i1i2 ↑ (i0 ↑, i1) (i0, i1 ↓ ) 1. i2 ↓ (i0 ↓, i1)( i0, i1 ↑ ) 1. i2 = i0 * i1 (i0>0, i1>0) i2 ↑ (i0 ↑, i1) (i0, i1 ↑ ) 1. i2 ↓ (i0 ↓, i1) (i0, i1 ↓ ) 1. i2 = i0 / i1 (i0>0, i0 > 0) i2 ↑ (i0 ↑, i1) (i0, i1 ↓ ) 1. i2 ↓ (i0- ↓ i1)( i0, i1 ↑ ).. 1. s0>s1(s0 >s1) = true(s0[k] ↑, s1) (s0, s1[l] ↓ ) 1. (s0 > s1) = false(s0[k] ↓,s2) (s0, s1[l] ↑ )
M ODEL M INER IDabc … ………… …
Jimple Predicates and Attributes of Triangle Program Jimple Predicate Attribute of UUT i0 > = $i3a > = b + c i1 > = $i4b > = a + c i2 > = $i5c > = a + b i0 != i1a != b i1 != i2b != c i0 == i1a = b i0 == i2a = c i1 == i2b = c For a given test input generated by rule-based method, predicates produce a set of T or F values Input (a=7.b=7,v=7) f f f f f t t t
Covert Test Inputs Using Attributes Test input ID abc a1 a2a3a4a5a6a7a8 O fffffttt ftfttfff fftttfff tffttfff4 … fffttftf fffttfft ffftffff tffttfff4
C4.5 mining algorithm The key idea of the algorithm is to calculate the highest normalized information gain of attributes and then build a decision node that splits on the attributes Tool Weka 3: ID abc a1a2a3a4a5a6a7a8o fffffttt ftfttfff fftttfff tffttfff4 … fffttftf fffttfft ffftffff tffttfff4
E MPIRICAL S TUDY
T HREE S TUDY S UBJECTS Line of CodeNumber of Predicates JavaJimpleJava Jimple (Allow duplications) Attributes (No duplication) Triangle Next Date Vending Machine
G OAL OF E MPIRICAL S TUDIES Measure fault detection capability # mutants killed /#mutants *100%
Measure fault detection capability: Process Step 1: Implant mutants Step 2: Build a decision tree model Step 3: Find mismatches Find possible causes Step 4: Calculate fault detectability Mutation OperatorExamples CategoryIDTypeOriginalReplaced Arithmetic Operations 1Arithmetic Operator Replacement a + ba - b 2Arithmetic Operator Insertion b + c-b + c Relations3Relational Operator Replacement a != ba == b Conditions4Conditional Operator Replacement (a==b) && (b==c) (a==b) || (b==c) Constants5Constant Value Modifications = as = b Return Values 6Return Value Modificationreturn sreturn s’ Insert bug Faulty version Find mismatches Two possible causes -Found bugs -assertEquals(“Equilateral”, new Trianlge(7,7,7).getTriType()) -Model is not correct -assertEquals (“Isosceles”, new Trianlge(7,7,7).getTriType()) Two possible causes -Found bugs -assertEquals(“Equilateral”, new Trianlge(7,7,7).getTriType()) -Model is not correct -assertEquals (“Isosceles”, new Trianlge(7,7,7).getTriType())
ID # of Mutants # of Tests Executed Oracle Results # Mutants Discovered# Faults in Models SDUSDUSDU Triangle Problem Next Date Problem Vending Machine Total
R ELATED W ORK Lo et al. (Lo, Cheng, Han, Khoo, & Sun, 2009), Milea et al. (Milea, Khoo, Lo, & Pop, 2012) mines a set of discriminative features capturing repetitive series of events from program execution traces. These features are then used to train a classier to detect failures. Bowring et al. (Bowring, Rehg, & Harrold, 2004) models program executions as Markov models, and a clustering method for Markov models that aggregates multiple program executions into effective behavior classifiers. (Pacheco & Ernst, 2005) Pacheco and Ernst build an operational model from observations of the software running properly. The operation model includes object invariants and properties. The object invariants are the conditions hold on entry and exit of all public methods. Our approach generates and classifies inputs based on the internal structure of the UUT. Briand (Briand, 2008) has proposed the use of machine learning techniques - including decision trees - for the test oracle problem. The decision tree model he has proposed is manually built from software requirements.
C ONCLUSIONS The first attempt to mine decision tree models from auto-generated test inputs based on static analysis of Java bytecode Our empirical study indicates that using the mined test oracles, average 94.67% mutants are killed by the generated test inputs.
Thanks
Future Research Direction Requirements Engineering & Natural language Process Generating UML diagrams, e.g., Use case, Class diagram Validating SRS Deriving test cases from SRS Software Design & Social Networks Analysis Utilizing SSA for analyzing communication diagram, class diagram, and sequence diagram for improving the quality of the software Software Implementation & Big Data Mining repository for software quality assurance using Hadoop Software Testing & Mobile/Cloud Application Testing mobile applications and distributed applications
Build Variable Dependency Tree (VDT)