[ESEM 2022] To What Extent Cognitive Driven Development Improves Code Readability

Paper presented at ESEM'22

Transcript

1. Gustavo Pinto
   To What Extent Cognitive Driven
   Development Improves Code
   Readability?
   1
   Victor Santiago Alberto de Souza
   Leonardo Barbosa
   UFPA & Zup
   Innovation
   UFPA Zup Innovation
   UFPA
   

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2. @zupinnovation zup.com.br
   <>
   @zupinnovation
   ● Software aging is far from
   new
   ● Many old programs are
   essential and still require
   maintenance
   Software gets old
   

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3. https://github.com/spring-projects/spring-framework/blob/b595dc1dfad9db534ca7b9e8f46bb9926b88ab5a/spring-core/src/main/java/org/springframework/asm/ClassReader.java (~4k LOC)
   

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4. https://github.com/spring-projects/spring-framework/blob/b595dc1dfad9db534ca7b9e8f46bb9926b88ab5a/spring-core/src/main/java/org/springframework/asm/ClassReader.java (~4k LOC)
   The goal of CDD is
   to avoid this!
   

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5. What is Cognitive Driven
   Development (CDD)?
   

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6. @zupinnovation zup.com.br
   <>
   @zupinnovation
   Cognitive-Driven Development (CDD)
   ● CDD is a design technique created at Zup
   Innovation, a Brazilian tech company
   ● It is based on two psychological theories
   ○ The Magical Number 7
   ○ The Cognitive Load Theory
   

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7. @zupinnovation zup.com.br
   <>
   @zupinnovation
   The Magical Number 7 (+/- 2) (Miller, 1956)
   ● We are only able to process 7 (+/- 2)
   units of information in short-term
   memory.
   ● As we receive more information
   simultaneously, we lose the ability
   to process it (and we tend to make
   mistakes).
   Units of information
   Comprehension
   

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8. @zupinnovation zup.com.br
   <>
   @zupinnovation
   Cognitive Load Theory (Sweller, 1988; Sweller, 2010)
   ● Each material has its own intrinsic
   complexity, and requires some
   cognitive effort
   ○ Sometimes big, sometimes small
   ● Certain types of items can hinder
   our understanding
   

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9. @zupinnovation zup.com.br
   <>
   @zupinnovation
   CDD in a nutshell
   ● It provides a limit indicating
   how much a code unit could
   grow
   ● It defines the code elements
   that hinder our understanding
   (and then should be limited)
   

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10. @zupinnovation zup.com.br
    <>
    @zupinnovation
    Cognitive-Driven Development (CDD)
    ● It provides a limit indicating
    how much a code unit could
    grow
    ● It defines the code elements
    that hinder our understanding
    (and then should be limited)
    SBES 2021 ICSME 2020
    

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11. It seems that CDD does
    limit the complexity
    during the software
    evolution process …
    

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12. But does it also improves
    code readability?
    

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13. @zupinnovation zup.com.br
    <>
    18 Zuppers
    2 OSS projects
    10s refactorings
    ENASE 2021
    

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14. CDD-Driven
    Refactorings
    Regular
    Refactorings
    The source code quality league (ENASE 2021)
    

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15. The source code quality league (ENASE 2021)
    CDD-Driven
    Refactorings
    

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16. We curated
    10 pairs of code
    10 CDD-Driven
    Refactorings
    10 Original
    Versions
    Does CDD improve code readability? (ESEM 2022)
    CDD-Driven
    Refactorings
    

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17. Does CDD improve code readability? (ESEM 2022)
    We asked 133
    devs to answer
    (and justify) their
    preferences
    Java Experience
    

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18. Does CDD improve code readability?
    Description Original CDD % Original % CDD
    Encapsulating error handling 67 66 50% 50%
    Encapsulating business rules 19 114 14% 86%
    Concatenating logical expressions 9 124 7% 93%
    Extracting classes 14 119 11% 89%
    Listing all imports 45 88 34% 66%
    Functional checking style 95 38 71% 29%
    Extracting classes 27 106 20% 80%
    Encapsulating for loops 10 123 8% 92%
    

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19. Description Original CDD % Original % CDD
    Encapsulating error handling 67 66 50% 50%
    Encapsulating business rules 19 114 14% 86%
    Concatenating logical expressions 9 124 7% 93%
    Extracting classes 14 119 11% 89%
    Listing all imports 45 88 34% 66%
    Functional checking style 95 38 71% 29%
    Extracting classes 27 106 20% 80%
    Encapsulating for loops 10 123 8% 92%
    Does CDD improve code readability?
    

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20. Encapsulating error handling
    Original (50%) CDD (50%)
    “Logging with try-catch is so
    common that I didn’t even need
    to read the code to understand
    its purpose."
    “the code is smaller and
    sounds like English"
    

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21. Encapsulating error handling
    “It is important to known which
    exception could be raised”
    “The method signature is
    clear and it makes it easier
    to understand its behavior”
    Original (14%) CDD (86%)
    

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22. Functional checking style
    “The ternary is an easy resource
    and there was no complex logic to
    justify a .map”
    Original (71%)
    CDD (29%)
    

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23. <>
    @zupinnovation zup.com.br
    

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