Software Engineering Research paper presentation

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Software EngineeringResearch paper presentation

• Ali Ahmad

• Formal Approaches to Software Testing
• Hierarchal GUI Test Case Generation
• Using Automated Planning

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Formal Approaches to Software Testing

• P. Dasiewicz
• IEEE Canadian Conference on Electrical and
  Computer Engineering
• 2002

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Introduction

• Software Testing checking and validating the
  correctness of software
• Time consuming
• Difficult
• Error prune
• Formal methods
• Specifying and verifying software systems using
  mathematical and logical approaches
• Target proof of correctness
• Some verification techniques
• Model Checking
• State space exploration

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Introduction (contd)

• Current methods are not feasible
• Too much manual effort
• Models that are very complex for analysis
• It is needed to overcome the following
• The state explosion problem
• Cost of creating models
• Applicability Design level
• Less complexity
• May reduce maintenance costs

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Introduction (contd)

• UML
• Simple, general purpose, visual modeling
• Specify, visualize, construct and document
• UML-statechart ? basis for dynamic behavioral
  description
• Objectives
• Overview model checking to the validation and
  test case generation (using UML statecharts and
  interaction diagrams)
• Applicability of formal methods to component
  integration and interaction testing

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Integration/Component Level Testing

• Offutt
• Changes in component states due to change events
• UMLTEST, integrated with Rational Rose ? Highly
  effective test cases can be generated for system
  level specification
• Test prefix ensure that the system is _at_ a
  certain pre state before performing the test
• Issues
• Interaction is not considered
• Some states may never been entered
• Incorporated UML collaboration diagrams

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Integration/Component Level Testing (contd)

• Yoon
• Test case generation based on UML sequence and
  collaboration diagrams
• A node that represents both integration target
  and message flow
• Testing technique
• Extract sequence diagram
• If concurrency, extract collaboration diagram
• Divide into ASF (Atomic System Function)
• Extract nodes and message flows
• Obtain test cases by applying test criteria (e.g.
  all-edge)
• Limitations
• May require a large number of sequence diagrams
• Test case coverage (only normal or abnormal flow)

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Integration/Component Level Testing (contd)

• Kim
• Divide statecharts into extended finite state
  machines
• Control flows are represented as paths
• Coverage criteria
• Path coverage
• State coverage
• Transition coverage
• Test cases
• breadth or depth first searches
• can be generated using the data flow on the UML
  statechart
• Determine whether class implements correct
  control and data flow

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System/Integration Testing

• Hartmann
• Testing the interfaces among several components
• UML statecharts ? Mealy Finite State Machines
  with restricted point to point synchronous
  communication model
• Incremental composition and reduction algorithm
• Test cases category partition method
• Limitations
• Interaction are modeled as synchronous
  communications
• Event exchanges contain no parameters
• No support for nested machines

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Source Code Based Testing

• Major problem State space explosion problem
• Reducing the state space entails eliminating
  irrelevant code segments
• Hatcliff
• Program slicing techniques
• Used by Bandera for translating Java code to
  Jimple, e.g. SPIN, SMV ? Generates a finite state
  model for the reduced code
• Java Path Finder
• Integrates model checking, program analysis and
  Testing
• Goal Apply formal methods at source level
• Initially, check for safety properties like
  deadlocks (LockTree)

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Translation of Statecharts

• Promela input modeling language for SPIN
• C-like, extended with non-deterministic, and loop
  guarded constructs
• Latella presents a translation from UML
  statecharts into Promela, where statecharts are
  first converted to hierarchal automata. A proof
  of correctness is also given

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Component Interaction Testing

• Major issue Are the components developed
  separately work properly together
• Formal methods of component interaction
• Define testing requirements
• Automatically generate the test cases using model
  checking
• Focus of authors research
• Component interaction of software systems
• Detect subtle interaction errors without
  duplicating the work _at_ unit level
• Underlying model Labeled transition system
• ObjectState modeling language to show the
  feasibility of creating formal models, it relies
  on hierarchal FSM.

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Hierarchal GUI Test Case Generation Using
Automated Planning

• Memon A., Pollack M., Lou Soffa M.
• IEEE Transactions on Software Engineering 2000

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Introduction

• GUI testing is difficult
• The interaction space is enormous
• Determining the coverage of test cases
• Regression testing is a major challenge
• Automation is necessary for generating GUI test
  cases
• PATHS Planning Assisted Tester for grapHical
  user interface Systems
• Input Possible goals for GUI user
• Generates sequences of events to satisfy the user
  goals, these become test cases

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Introduction (contd)

• PATHS performs automated analysis of the
  hierarchal structure of the GUI to create
  hierarchal operators that will be used during
  plan generation
• Contribution to Research
• Make use of an AI technique (Automated Planning)
• Exploits GUI structural features
• Makes Regression testing easier
• The test suite is portable
• Allow the reuse of operator definitions that
  commonly appear across GUIs

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Overview

• GUI consists of components like labels, buttons,
  menus, and pop-up lists
• Example Microsoft WordPad
• GUI has 2 types of windows
• GUI windows
• Object windows,
• doesnt contain any
• window components

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Overview (contd)

• PATHS- Plan Generation
• Inputs
• Initial state
• Goal state
• A set of operators applied to a set of objects
• Preconditions and effects
• Solution to a Planning Problem sequence of
  instantiated operators which result in the goal
  state when executed in the initial state
• 2 Phases
• Setup
• Create a hierarchal model of the GUI
• Plan Generation
• Specify scenarios (initial and goal states)
• PATHS generate a test suit for the scenarios

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Overview (contd)

• Role of Test Designer and PATHS during test
  generation
• GUI Events and Planning Operators

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Overview (contd)

• Operator Event Mapping
• Example operator Edit_Cut

Abstract Invokes a window that monopolizes the
user interaction
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Overview (contd)

• High level plan
• Expanded plan

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Plan Generation

• GUI test case generation can be modeled by
• hierarchal plans that doesnt require conflict
  resolution

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Planning GUI Test Cases

• Developing a representation for the GUI and its
  operators
• Operator Derivation Process
• Traverse the GUI and press on its components, the
  label is read off the component label
• GUI events
• Menu open (File, Edit)
• Unrestricted focus (Basic shapes in PowerPoint)
• Restricted focus (Edit-Preferences in PowerPoint)
• System-interaction (Cut and paste)
• Planning Operators
• System-Interaction
• Abstract
• Modeling Initial and Goal States and Generating
  Test Cases using algorithm
• Generating multiple plans in PATHS
• Creating multiple linearizations of the partial
  plans
• Repeating the planning process, thus generating a
  different test case

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Planning GUI Test Cases (Contd)
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Planning GUI Test Cases (Contd)
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Planning GUI Test Cases (Contd)
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Planning GUI Test Cases (Contd)
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Some Experimental Results

• Multiple Tasks
• Hierarchal vs. Single Layer

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Questions