CSC309 Lecture 18

Software Engineering II
Test Driven Development
(202305)

Transcript

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   CSC 309
   Software Engineering II
   Lecture 18:
   Test Driven Development
   Dr. Javier Gonzalez-Sanchez
   javiergs@calpoly.edu
   www.javiergs.com
   Building 14 -227
   Office Hours: By appointment
   

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   Javier Gonzalez-Sanchez | CSC 309 | Winter 2023 | 3
   § Final Exam
   Wednesday, June 14 at 1:10 pm
   https://registrar.calpoly.edu/spring-final-exam-schedule
   § Final Project
   Friday, June 09 (lecture Time)
   § Academic Holiday
   Monday, May 29 (lecture Time)
   § Project Status Report 3
   Friday, May 26 (lecture Time)
   Schedule
   

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   Previously …
   

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   int x;
   void student () {
   world();
   for (int x=0; x<10; x++) {
   hello(); x = x + 1; break;
   }
   }
   Case 4
   Input:
   Output:
   

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   Objects
   Begin
   End
   Call a method
   Instruction
   Input or Output
   Variable declaration
   Condition
   

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   1. Create a GUI
   2. Develop a Lexer that splits and classifies words
   3. A parser method for method
   4. A parser method for local variables
   5. A parser method for instructions
   6. A parser method for input/output (println)
   7. A parser method for the if condition
   8. A parser method for the for loop
   9. Test Cases for Lexer
   10. Test Cases for Parser
   Issues
   

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   Unit Testing
   

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

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   Definition
   Testing a unit - the smallest
   piece of code that can be
   logically isolated in a system.
   (a method in Java)
   

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    Definition
    TDD suggests that the code is
    developed or changed exclusively
    on the basis of Unit Testing.
    

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    Test Case
    

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    Source Code
    

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    Test-Driven Development
    

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    TDD
    

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    § You cannot test every possible input, parameter value, etc.
    So, you must think of a limited set of tests likely to expose bugs.
    § Think about boundary cases
    positive; zero; negative numbers
    right at the edge of an array or collection's size
    § Think about empty cases and error cases
    0, -1, null; an empty list or array
    § Test behavior in combination
    maybe add usually works but fails after you call to remove
    make multiple calls; maybe the size fails the second time only
    Tips for Testing
    

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    § Test one thing at a time per test method.
    10 small tests are much better than 1 test 10x as large.
    § Each test method should have a few (likely 1) assert
    statements.
    If you assert many things, since the first that fails will stop the
    test, you won't know whether a later assertion would have
    failed.
    § Torture tests are okay, but only in addition to simple tests.
    Trustworthy tests
    

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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 18:
    Test Driven Development
    Dr. Javier Gonzalez-Sanchez
    javiergs@calpoly.edu
    Building 14 -227
    Office Hours: By appointment
    

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    Scenario
    Box
    Name1
    Name2
    class Name1 {
    }
    class Name2 {
    method(){
    Name1
    Cat
    }
    }
    class Cat
    extends Name1 {
    }
    Cat
    

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    Let’s Work
    

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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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