An Automated Test Generation Process from UML Models to TTCN3

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An AutomatedTest Generation Processfrom UML
Models to TTCN-3

• Jens R. Calamé

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Our Test Generation Process
System Specification (e.g. UML)
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
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Abstraction

• Motivation Test Generation with TGV is based on
  enumerative techniques? suffers from state-space
  explosion
• Finite state-space by data abstraction
• 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

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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

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Test Execution

• Pre-solve one trace to pass statically(skip
  internal ?-steps)
• Execute this trace until the SUT leaves it
• Try to find a trace to pass ? solve and execute
  it
• If no trace to passTry to find a trace to
  inconc ? solve it
• If no trace to inconcset test verdict fail

!initPin(x00)
!initBalance(x10)
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0
1
!getPin(x20)
?pinInCorrect
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INCONC
?pinCorrect
?lowBalance
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!getAmount(x40)
!getBalance
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PASS
?Money(x70)
?Balance(x50)
!getAmount(x60)
?eatCard
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Future Work (Theoretical Part)

• Proof of completeness of the presented approach
• If there is a failure in the SUT is there a
  test case that finds it?
• ?-steps handling not yet fully satisfying
• In blackbox testing ?-steps are skipped
• However for online constraint-solving ?-steps
  contain necessary information (e.g. internal
  assignments)
• Possible solution assignment collection in first
  visible action after sequence of ?-steps (loops?)
• Theoretical foundation of suspension handling
  (quiescence, ?-loops again)

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Conclusion

• Actual status
• Data abstraction algorithm is implemented for
  µCRL
• Parameterization constraint generation is
  implemented
• Whole test generation process is applied to
  CEPS(but not yet test execution)
• Generation of TTCN-3 test cases ongoing work
• Future work
• Correct handling of ?-steps in blackbox-testing
• Handling of suspension traces in the SUT
• Proof that a complete set of test cases is
  generated
• Test data selection and test case
  parameterization
• Formalization of UML-Models for test generation

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