1. Test Generation with Abstraction and Concretization
Jens R. Calamé
Natalia Ioustinova
Jaco van de Pol

2. Our Approach in Context with MDA
Abstraction and test generation from platform independent models
Starting point: UML-Model
Formalization and abstraction of the specification before test generation
Generation of parameterizable test cases on a platform-independent level
Generation of Rules for Data Selection
PIM
PIT
PSM
PST
Code
TestCode
1st Dutch Workshop on Formal Testing Techniques

3. Our Test Generation Process
System Specification (informal)
PIM
PIT
System Specification (formal)
Abstraction
Abstract System Specification
Test Case
Generation
Test Purpose
TGV
Abstract Test Case
TTCN-3
Generation
Constraint
Generation
Parameterizable
Test Case (TTCN-3)
Rule System for
Data Selection
1st Dutch Workshop on Formal Testing Techniques

4. 1st Dutch Workshop on Formal Testing Techniques
Abstraction
Motivation: Test Generation with TGV is based on enumerative techniques
Given: formal specification with infinite state-space w.r.t. input data
Result: formal specification with finite state-space w.r.t. input data
System abstraction on specification-level:
Replace all input values by one constant chaos (*)
Propagate this * through the system
Transform conditions based on * to nondeterministic choice
 Abstracted system is an over-approximation of original system
1st Dutch Workshop on Formal Testing Techniques

5. Implementation of Abstraction
Program transformation of a µCRL process specification:
For each datatype D add one additional type D* with
the constructor *D and
a lifting function :DD*
For all datatypes D realize all functions additionally for D* and lift them (strict lifting, except for datatype Boolean)
Lift all action and process parameters
Replace all input variables in the process definition by * (propagation of * happens automatically) and lift conditions
In the process initialization use
original values, lifted by , or
use *
1st Dutch Workshop on Formal Testing Techniques

6. Our Test Generation Process
System Specification (informal)
System Specification (formal)
Abstraction
Abstract System Specification
Test Case
Generation
Test Purpose
TGV
Abstract Test Case
TTCN-3
Generation
Constraint
Generation
Parameterizable
Test Case (TTCN-3)
Rule System for
Data Selection
1st Dutch Workshop on Formal Testing Techniques

7. Test Case Generation with TGV
TGV: Test Generation with Verification Technology
Part of CADP toolkit
Link between µCRL toolkit and CADP toolkit
Test Generation with TGV
Based on a labeled transition system (enumeration of all data values)
Guided by a test purpose (focus of generated test cases)
1st Dutch Workshop on Formal Testing Techniques

8. Our Test Generation Process
System Specification (informal)
System Specification (formal)
Abstraction
Abstract System Specification
Test Case
Generation
Test Purpose
TGV
Abstract Test Case
TTCN-3
Generation
Constraint
Generation
Parameterizable
Test Case (TTCN-3)
Rule System for
Data Selection
1st Dutch Workshop on Formal Testing Techniques

9. Generation of Data Selection Rules
Given:
Abstract test case (control flow information + internal data)
Original specification (data dependencies)
Result: (generated Prolog implementation)
Rules, representing ADT functions of the original specification (meta language)
Rule system based on specification: one rule for each transition in original system, containing
Conditions
Assignments (internally or from input actions, resp.)
Test oracle based on abstract test case (query to rule system)
Invocation of all selected actions as a conjunction
1st Dutch Workshop on Formal Testing Techniques

10. 1st Dutch Workshop on Formal Testing Techniques
Case Study CEPS
Common Electronic Purse Specifications
Standard for electronic payment cards and infrastructure
Appropriate to experimenting with our approach due to its data orientation
Experience with CEPS (card application)
Abstracted system of a challenging size (17.5 mio. transitions and 3 mio. states)
Size could be reduced further with unused variable analysis and LTS minimization (5487 transitions and 1627 states)  From the resulting system, test cases and data constraints could be generated easily
1st Dutch Workshop on Formal Testing Techniques

11. Conclusion and Future Work
*-Abstraction algorithm is implemented for µCRL
TGV is applied on abstracted systems
Parameterization constraint generation is defined and implemented
The whole test generation process is applied to the CEPS case study
Future work
Generation of parameterizable TTCN-3 test cases
Formalization of UML-Models for test generation
Comparison of STG to our approach
(First release of STG: Oct. 2005)
1st Dutch Workshop on Formal Testing Techniques