CSC309 Lecture 04

Software Engineering II
Verification, Validation, and Testing
(202301)

Transcript

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   CSC 309
   Software Engineering II
   Lecture 04:
   Software Verification, Validation, and Testing
   Dr. Javier Gonzalez-Sanchez
   javiergs@calpoly.edu
   www.javiergs.com
   Building 14 -227
   Office Hours: By appointment
   

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   Previously …
   

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   code
   Key Ideas CSC 309
   idea
   requirements
   architecture
   design
   quality measure
   

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   Metrics
   Size
   LOC
   eLOC
   lLOC
   Understandability
   Comments
   Whitespaces
   Complexity
   Average, Max, Min LOC
   Interface Complexity
   Cyclomatic Complexity
   Software Metrics
   

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   Structural Metrics
   Abstract
   concrete
   Stable
   Hard to Change
   Only incoming dependencies
   Unstable
   Changeable
   Only outgoing dependencies
   

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   Software Testing
   Unit Testing
   

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   Key Ideas CSC 309
   idea
   requirements
   architecture
   design
   code
   unit testing
   quality measure
   

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   § Validation. It is about requirements. Are we building the right product? Does
   this software do what it needs to do?
   § Verification. It is about design. Are we building the product right? Does this
   meet its requirements?
   § Testing. Examination of the behavior of a program by executing it on
   sample data sets.
   Definition
   

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   Testing
   White Box
   (Verification)
   Unit Testing
   Integration Testing
   Black Box
   (Validation)
   System Testing
   Scenario-based
   testing
   Model-based testing
   Testing
   

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    § Unit testing is the testing of an individual unit or group of related units.
    § It test that a unit is producing expected output against given input.
    § Each Unit developer must define Unit Test Cases for that Unit.
    § Unit Testing Frameworks are tools and libraries that help to implement
    the Unit Testing process. Example JUnit
    Unit Testing
    

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    Example
    

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    Example
    

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    § Missing or Bad requirements
    § Limited time and money
    § Exhaustive testing is not possible
    § Sampling
    Limitations and Constraints
    

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    Software Testing
    Coverage
    

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    § Statement Coverage: every statement is executed at least 1 time.
    § Decision Coverage: every decision point is executed at least 1 time
    § Decision-Condition Coverage: every decision tested with all possible
    outcomes
    Coverage
    

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    Example
    

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    1. if (x<1 || y>5 && z!=0 || flag==true && s==null)
    2. doThis();
    3. else
    4. doThat();
    § How many Test cases are needed to Test for 100%
    statement coverage?
    § How many Test cases are needed to Test for 100%
    decision coverage?
    § How many Test cases are needed to Test for 100%
    decision-condition coverage?
    Decision-Condition Coverage
    

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    Questions
    

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    Office Hours
    Tuesday and Thursday 3 - 5 pm
    But an appointment required
    Sent me an email – javiergs@calpoly.edu
    

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    CSC 309
    Software Engineering II
    Lab 04:
    Coverage
    Dr. Javier Gonzalez-Sanchez
    javiergs@calpoly.edu
    www.javiergs.com
    Building 14 -227
    Office Hours: By appointment
    

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    Lab
    Calculate coverage for the
    following scenarios
    

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    1.x = 0;
    2.if (x < 10)
    3. doSomething();
    4.x =5;
    Total Statements?
    Statement coverage?
    Decision coverage?
    Test Yourselves
    

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    1. if (a <10 || b>5)
    2. x = 50
    3. else
    4. x = 0;
    5. if (w == 5 || y>0)
    6. z = 48;
    7. else
    8. z = 5;
    Total Statements?
    Statement Coverage with a = 0, b=0, w=0, y=0 ?
    Statement Coverage with a=10, b=4, w=5, y = anything ?
    Note: Remember that coverage is cumulative
    Test Yourselves
    

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    1. start =0;
    2. end = 0;
    3. found = false;
    4. while (starts <= end and ! found ) {
    5. middle =(start - end)/2;
    6. if (key > table[middle]) {
    7. start = middle +1
    8. } else if (key = table[middle]) {
    9. found = T
    10. LOC = middle;
    11. } else
    12. end = middle -1;
    13. }
    14. }
    //TestCase1 table={10, 20, 30, 40, 50, 60, 70}, key=55
    //TestCase2 table={10, 20, 30, 40, 50, 60, 70}, key=40
    Test Yourselves
    

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    Let’s Work
    

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    One More For Homework
    

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    CSC 309 Software Engineering II
    Javier Gonzalez-Sanchez, Ph.D.
    javiergs@calpoly.edu
    Winter 2023
    Copyright. These slides can only be used as study material for the class CSC308 at Cal Poly.
    They cannot be distributed or used for another purpose.
    

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