Android MV* Patterns & Unit Testing

"Android MV* Patterns & Unit Testing", talk delivered in DevFest Ahmedabad 2016 http://devfest.gdgahmedabad.com/

- Android MVC vs MVP vs MVVM
- Android Unit Testing
- Why Unit Testing
- Why Good code base
- Android Testing frameworks and tools
- Continuous Integration in Android

Transcript

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2. PareshMayani.apk
   Founder/Organizer, GDG Ahmedabad
   Technical Lead @ Lets Nurture
   Application Architect
   

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3. Good/Clean code base?
   What is that? Why should we have good/clean code base?
   

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4. Scalable
   

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5. Scalable | Stable
   

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6. Scalable | Stable | Testable
   

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7. Scalable | Stable | Testable | Modular
   

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8. Application Architecture?
   And why do I care?
   

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9. MV* Patterns?
   And why do I care?
   

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10. MV (C | P | VM)
    Model
    Business logic
    Data source of the application
    Network layer, database operations
    

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11. MV (C | P | VM)
    View
    Business logic
    Data source of the application
    Network layer, database operations
    Responsible for displaying data
    Model
    

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12. MVC
    Model View Controller
    

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13. View
    Model
    Controller
    Controller manipulates, edit, uses data model
    and show it to users via View.
    

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14. View
    Model
    Controller
    In Android, Activity/Fragments can act as both
    View and Controller
    

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15. MVP
    Model View Presenter
    

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16. Presenter
    Model
    View
    1 .. 1
    

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17. Presenter
    Model
    View
    1 .. 1
    Presenter is a simple java class that do not
    contain any UI components, it just manipulates
    data from model and display in on View.
    

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18. MVVM
    Model View ViewModel
    

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19. ViewModel
    Model
    View
    1 .. *
    Many View can be mapped to one View-Model
    

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20. MVC vs MVP vs MVVM
    Show me flow how it actually works
    

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21. Passes
    call to
    Fire
    events
    Manipulates
    Model-View-Controller
    Controller Model
    View
    User Interaction
    

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22. Passes
    call to
    Fire
    events
    Manipulates
    Model-View-Controller
    Controller Model
    View
    User Interaction
    Passes
    call to
    Manipulates
    Model-View-Presenter
    Presenter
    Model
    View
    Updates
    User Interaction
    Fire events
    

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23. Passes
    call to
    Fire
    events
    Manipulates
    Model-View-Controller
    Controller Model
    View
    User Interaction
    Passes
    call to
    Manipulates
    Model-View-Presenter
    Presenter
    Model
    View Bi-directional
    Data Binding
    Manipulates
    Model-View-ViewModel
    ViewModel
    Model
    View
    Updates
    User Interaction User Interaction
    Fire
    events
    Fire events
    

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24. MVC vs MVP vs MVVM
    Which one to follow?
    

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25. Activity/Fragment/View
    should be Business logic free
    

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26. Can you unit test everything?
    

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27. Unit Testing
    Why to test?
    

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28. Local unit tests
    Instrumented tests
    Test Types
    

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29. Located at module-name/src/test/java/.
    These tests run on the local JVM and do not have
    access to functional Android framework APIs.
    Local unit tests
    

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30. Located at module-name/src/androidTest/java/.
    These are all tests that must run on an Android
    hardware device or an Android emulator.
    Instrumented (end-to-end) tests
    

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31. 1) Instrumented test 2) Local JVM Test
    

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32. Why Unit Testing?
    Why should we write unit test?
    

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33. “Unit Testing is a level of software testing where
    individual units/ components of a software are tested. “
    The purpose is to validate that each unit of the software
    performs as designed.”
    All possible scenarios
    

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34. Unit tests are for the software developers
    Unit tests are written by software developers
    

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35. Options: JUnit, Robolectric
    Frameworks: Mockito, PowerMock
    Unit Testing
    

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36. Mocking => @mock
    @spy
    Stubbing => when().thenreturn(true/false)
    Verifying => verify()
    Mockito
    

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37. // You can mock concrete classes and interfaces
    TrainSeats seats = mock(TrainSeats.class);
    // stubbing appears before the actual execution
    when(seats.book(Seat.near(WINDOW).in(FIRST_CLASS))).thenReturn(BOOKED);
    // the following prints "BOOKED"
    System.out.println(seats.book(Seat.near(WINDOW).in(FIRST_CLASS)));
    // the following prints "null" because .book(Seat.near(AISLE).in(FIRST_CLASS))) was not stubbed
    System.out.println(seats.book(Seat.near(AISLE).in(FIRST_CLASS)));
    // the following verification passes because .book(Seat.near(WINDOW).in(FIRST_CLASS)) has been
    invoked
    verify(seats).book(Seat.near(WINDOW).in(FIRST_CLASS))
    // the following verification fails because .book(Seat.in(SECOND_CLASS)) has not been invoked
    verify(seats).book(Seat.in(SECOND_CLASS))
    Example
    

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38. Options: Robotium, Espresso
    Firebase Test lab support
    Android Studio test recorder
    Instrumentation tests
    

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41. Continuous Integration
    Can I perform unit testing automatically whenever software builds?
    

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42. Jenkins (Open source)
    Travis / Circle CI / Atlanssian Bamboo
    Performs testing on triggering actions like PR merge
    Automated reporting: Send email if build fails
    Auto publishing to play store
    Continuous Integration
    

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43. Demo Time
    MVP Pattern & Unit Testing
    

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44. https://goo.gl/Z4dy8G
    https://github.com/googlesamples/android-architecture
    Resources
    

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45. No Questions!
    

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46. Thank you!
    Paresh Mayani
    @pareshmayani
    Grab This Presentation
    https://goo.gl/Xsvpi3
    

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