Lecture 3— Application Programming Interface

"Software Testing for Complex Intelligent Systems and Autonomous Vehicles" online course.

The lecture is available via the link: https://youtu.be/Ka6JNG12Qn4
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Transcript

1. 1 Build Software to Test Software exactpro.com
   Lecture 3
   Application Programming Interface
   Software Testing for
   Complex Intelligent Systems
   and Autonomous Vehicles
   Online Course
   

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2. 2 Build Software to Test Software exactpro.com
   Lecture Overview
   What is API: definition, API vs protocol, API types
   and their place under the sun
   API examples in complex financial systems
   API examples that will be used at the course
   seminars
   

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3. 3 Build Software to Test Software exactpro.com
   3 Types of Systems
   

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4. 4 Build Software to Test Software exactpro.com
   Useful Links
   https://en.wikipedia.org/wiki/API
   

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5. 5 Build Software to Test Software exactpro.com
   Useful Links
   https://youtu.be/GZvSYJDk-us
   

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6. 6 Build Software to Test Software exactpro.com
   Useful Links
   https://www.youtube.com/playlist?list=PLcgRuP1JhcBP8Kh0MC53GH_pxqfOhTVLa
   

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7. 7 Build Software to Test Software exactpro.com
   Useful Links
   https://www.altexsoft.com/blog/engineering/what-is-api-definition-types-specifications-documentation/
   

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8. 8 Build Software to Test Software exactpro.com
   https://rapidapi.com/blog/types-of-apis/
   Useful Links
   

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9. 9 Build Software to Test Software exactpro.com
   What is an Interface
   

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10. 10 Build Software to Test Software exactpro.com
    What is API
    API is an interface allowing two independent
    software components to exchange information.
    API plays the role of an intermediary between
    internal and external software functions.
    

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11. 11 Build Software to Test Software exactpro.com
    Web Application Structure
    Web
    Servers
    Static
    Content
    Browser
    DOM model
    HTTP(S)
    Request
    HTTP(S)
    Response
    Internet
    CSS
    HTML
    Javascript
    Everything
    a user sees
    in the
    browser is
    a mix of
    HTML,
    CSS, and
    JavaScript
    Browser
    sends
    requests to
    the server,
    receives
    responses
    and visualizes
    them as a
    page
    The back-end
    server-side
    scripts process
    the request, pull
    what they need
    from the database
    and application
    servers and then
    send it back
    1 2
    

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12. 12 Build Software to Test Software exactpro.com
    Application
    Servers
    Data
    Web
    Servers
    Static
    Content
    Browser
    DOM model
    HTTP(S)
    Request
    HTTP(S)
    Response
    Internet
    CSS
    HTML
    Javascript
    Web Application Structure
    The back-end
    server-side
    scripts process
    the request, pull
    what they need
    from the database
    and application
    servers and then
    send it back
    2
    Everything
    a user sees
    in the
    browser is
    a mix of
    HTML,
    CSS, and
    JavaScript
    Browser
    sends
    requests to
    the server,
    receives
    responses
    and visualizes
    them as a
    page
    1
    

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13. 13 Build Software to Test Software exactpro.com
    Application
    Servers
    Data
    Web
    Servers
    Static
    Content
    Browser
    DOM model
    HTTP(S)
    Request
    HTTP(S)
    Response
    Internet
    CSS
    HTML
    Javascript
    Web Application Structure
    Browser
    sends
    requests to
    the server,
    receives
    responses
    and visualizes
    them as a
    page
    The back-end
    server-side
    scripts process
    the request, pull
    what they need
    from the database
    and application
    servers and then
    send it back
    1
    Client-side
    scripts
    Run in the
    browser and
    process
    information
    without
    sending
    requests to
    the server
    3
    2
    Everything
    a user sees
    in the
    browser is
    a mix of
    HTML,
    CSS, and
    JavaScript
    

    View Slide

14. 14 Build Software to Test Software exactpro.com
    Application
    Servers
    Data
    Web
    Servers
    Static
    Content
    Browser
    DOM model
    HTTP(S)
    Request
    HTTP(S)
    Response
    Internet
    CSS
    HTML
    Javascript
    Web Application Structure
    Everything
    a user sees
    in the
    browser is
    a mix of
    HTML,
    CSS, and
    JavaScript
    Browser
    sends
    requests to
    the server,
    receives
    responses
    and visualizes
    them as a
    page
    The back-end
    server-side
    scripts process
    the request, pull
    what they need
    from the database
    and application
    servers and then
    send it back
    1
    Client-side
    scripts
    Run in the
    browser and
    process
    information
    without
    sending
    requests to
    the server
    3
    AJAX allows to
    create
    asynchronous web
    interactions without
    interfering with the
    display and the
    behaviour of the
    existing page
    4
    2
    

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15. 15 Build Software to Test Software exactpro.com
    Application
    Servers
    Data
    Web
    Servers
    Static
    Content
    Browser
    DOM model
    HTTP(S)
    Request
    HTTP(S)
    Response
    Websocket
    Internet
    CSS
    HTML
    Javascript
    Web Application Structure
    Browser
    sends
    requests to
    the server,
    receives
    responses
    and visualizes
    them as a
    page
    The back-end
    server-side
    scripts process
    the request, pull
    what they need
    from the database
    and application
    servers and then
    send it back
    1
    Client-side
    scripts
    Run in the
    browser and
    process
    information
    without
    sending
    requests to
    the server
    3
    AJAX allows to
    create
    asynchronous web
    interactions without
    interfering with the
    display and the
    behaviour of the
    existing page
    4
    2
    Everything
    a user sees
    in the
    browser is
    a mix of
    HTML,
    CSS, and
    JavaScript
    WebSocket enables
    interaction between a web
    browser and a web server
    with lower overhead than
    half-duplex alternatives
    such as HTTP polling
    5
    

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16. 16 Build Software to Test Software exactpro.com
    Application
    Servers
    Data
    Web
    Servers
    Static
    Content
    Browser
    DOM model
    HTTP(S)
    Request
    HTTP(S)
    Response
    Websocket
    Internet
    CSS
    HTML
    Javascript
    Web Application Structure
    Browser
    sends
    requests to
    the server,
    receives
    responses
    and visualizes
    them as a
    page
    The back-end
    server-side
    scripts process
    the request, pull
    what they need
    from the database
    and application
    servers and then
    send it back
    1
    Client-side
    scripts
    Run in the
    browser and
    process
    information
    without
    sending
    requests to
    the server
    3
    AJAX allows to
    create
    asynchronous web
    interactions without
    interfering with the
    display and the
    behaviour of the
    existing page
    4
    2
    Everything
    a user sees
    in the
    browser is
    a mix of
    HTML,
    CSS, and
    JavaScript
    WebSocket enables
    interaction between a web
    browser and a web server
    with lower overhead than
    half-duplex alternatives
    such as HTTP polling
    5
    

    View Slide

17. 17 Build Software to Test Software exactpro.com
    CSS
    HTML
    Javascript
    Application
    Servers
    Data
    Web
    Servers
    Static
    Content
    Browser
    DOM model
    HTTP(S)
    Request
    HTTP(S)
    Response
    Websocket
    Internet
    Web Application Structure
    Browser
    sends
    requests to
    the server,
    receives
    responses
    and visualizes
    them as a
    page
    The back-end
    server-side
    scripts process
    the request, pull
    what they need
    from the database
    and application
    servers and then
    send it back
    1
    Client-side
    scripts
    Run in the
    browser and
    process
    information
    without
    sending
    requests to
    the server
    3
    AJAX allows to
    create
    asynchronous web
    interactions without
    interfering with the
    display and the
    behaviour of the
    existing page
    4
    2
    Responsive
    front-end
    design allows
    a site to adapt
    to user’s
    device
    Everything
    a user sees
    in the
    browser is
    a mix of
    HTML,
    CSS, and
    JavaScript
    WebSocket enables
    interaction between a web
    browser and a web server
    with lower overhead than
    half-duplex alternatives
    such as HTTP polling
    5
    

    View Slide

18. 18 Build Software to Test Software exactpro.com
    WebSocket enables
    interaction between a web
    browser and a web server
    with lower overhead than
    half-duplex alternatives
    such as HTTP polling
    Responsive
    front-end
    design allows
    a site to adapt
    to user’s
    device
    Everything
    a user sees
    in the
    browser is
    a mix of
    HTML,
    CSS, and
    JavaScript
    5
    CSS
    HTML
    Javascript
    Application
    Servers
    Data
    Web
    Servers
    Static
    Content
    Browser
    DOM model
    HTTP(S)
    Request
    HTTP(S)
    Response
    Websocket
    Internet
    Web applications
    are always
    multi-user
    applications, and
    many of them
    work under heavy
    load and are
    subject to
    concurrency
    access
    6
    Web Application Structure
    Browser
    sends
    requests to
    the server,
    receives
    responses
    and visualizes
    them as a
    page
    The back-end
    server-side
    scripts process
    the request, pull
    what they need
    from the database
    and application
    servers and then
    send it back
    1
    Client-side
    scripts
    Run in the
    browser and
    process
    information
    without
    sending
    requests to
    the server
    3
    AJAX allows to
    create
    asynchronous web
    interactions without
    interfering with the
    display and the
    behaviour of the
    existing page
    4
    2
    

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19. 19 Build Software to Test Software exactpro.com
    A Human from the Point of View of an App
    

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20. 20 Build Software to Test Software exactpro.com
    A Human from the Point of View of an App
    

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21. 21 Build Software to Test Software exactpro.com
    Human → Driverless Vehicle
    

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22. 22 Build Software to Test Software exactpro.com
    A Human from the Point of View of an App
    

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23. 23 Build Software to Test Software exactpro.com
    Human → Driverless Vehicle
    

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24. 24 Build Software to Test Software exactpro.com
    API around us: Looking to the Future
    https://www.capgemini.com/research/world-quality-report-wqr-20-21/
    

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25. 25 Build Software to Test Software exactpro.com
    Human-Machine Interaction Interface
    

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26. 26 Build Software to Test Software exactpro.com
    Human-Machine Interaction Interface
    

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27. 27 Build Software to Test Software exactpro.com
    API vs. Protocol
    Protocol:
    API: Interaction rules,
    language
    A way of
    communicating a
    message
    

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28. 28 Build Software to Test Software exactpro.com
    Protocol - API - Protocol
    Protocol
    Protocol
    API
    TCP/IP
    FIX Messages
    FIX Protocol
    

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29. 29 Build Software to Test Software exactpro.com
    PPP: Processes, Platforms, People
    

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30. 30 Build Software to Test Software exactpro.com
    PPP: Processes, Platforms, People
    https://zero-outage.com/
    

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31. 31 Build Software to Test Software exactpro.com
    API Types: Private, Partner, Public
    https://www.altexsoft.com/blog/engineering/what-is-api-definition-types-specifications-documentation/
    

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32. 32 Build Software to Test Software exactpro.com
    API types: Library, Code, Data
    >
    

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33. 33 Build Software to Test Software exactpro.com
    Example: NASDAQ – GENIUM OMNET API
    (Library)
    https://www.nasdaq.com/solutions/genium-inet-protocol-specific
    ations
    

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34. 34 Build Software to Test Software exactpro.com
    Example: NASDAQ – FIX Protocol (Data)
    https://www.nasdaq.com/docs/2020/10/01/GeniumFIX_ProtSpec_
    Nordic_v223.pdf
    https://www.fixtrading.org/
    

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35. 35 Build Software to Test Software exactpro.com
    Example: Bitcoin (Code)
    >
    

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36. 36 Build Software to Test Software exactpro.com
    Question
    Python-based API of the LGSVL Simulator – what type?
    >
    

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37. 37 Build Software to Test Software exactpro.com
    FIX Trading Community – Monitoring,
    Onboarding and Software Testing Group
    https://www.fixtrading.org/groups/mostwg/
    

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38. 38 Build Software to Test Software exactpro.com
    API Examples
    https://rapidapi.com/blog/types-of-apis/
    

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39. 39 Build Software to Test Software exactpro.com
    API Examples
    https://docs.corda.net/docs/corda-os/4.7/api-flows.html
    https://rapidapi.com/blog/top-anime-manga-apis/
    https://rapidapi.com/blog/best-beer-wine-alcohol-api/
    7 APIs Everyone in the Anime/Manga
    Industry Should Be Using
    Top 8+ Beer, Wine, & Alcohol APIs
    for Developers [2021]
    API: Flows|Corda
    

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40. 40 Build Software to Test Software exactpro.com
    Documenting API
    “APIs should be self-documenting: It should rarely
    require documentation to read code written to a good
    API. In fact, it should rarely require documentation to
    write it.”
    https://www.infoq.com/articles/API-Design-Joshua-Bloch/
    https://www.youtube.com/watch?v=aAb7hSCtvGw
    “APIs should be easy
    to use and hard to
    misuse. It should be
    easy to do simple
    things; possible to do
    complex things; and
    impossible, or at least
    difficult, to do wrong
    things.”
    

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41. 41 Build Software to Test Software exactpro.com
    API Specs
    ● https://en.wikipedia.org/wiki/API#Documentation
    ● An example of a human-readable specification:
    https://connect2.euronext.com/sites/default/files/it-docum
    entation/Euronext%20Markets%20-%20Optiq%20OEG%20
    Client%20Specifications%20-%20FIX%205.0%20Interface%2
    0-%20v2.0.0.pdf
    ● An example of a machine-readable specification:
    https://www.fixtrading.org/standards/fix-orchestra/,
    https://youtu.be/eOIA_7bRQyI
    

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42. 42 Build Software to Test Software exactpro.com
    Interface Stability
    https://developer.gnome.org/programming-guidelines/stable/api-stability.html.en
    

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43. 43 Build Software to Test Software exactpro.com
    Plugins
    

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44. 44 Build Software to Test Software exactpro.com
    LGSVL Simulator: A High Fidelity
    Simulator for Autonomous Driving
    https://arxiv.org/pdf/2005.03778.pdf
    

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45. 45 Build Software to Test Software exactpro.com
    Conferences
    2021 IEEE AI Testing Conference. Paper
    submission until 30 April.
    http://ieeeaitests.com/
    TMPA - International Conference on
    Software Testing, Machine Learning and
    Complex Process Analysis
    https://tmpaconf.org/
    

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46. 46 Build Software to Test Software exactpro.com
    LGSVL Simulator: A High Fidelity Simulator
    for Autonomous Driving
    https://arxiv.org/pdf/2005.03778.pdf
    

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47. 47 Build Software to Test Software exactpro.com
    LGSVL Simulator and its APIs
    Real
    Road
    Testing
    Simulation
    Python API
    Analytics&Visualization
    Logs Logs
    AD Stack
    Simulator
    Plugins
    Digital Twin Map (or
    Procedurally Generated Map)
    (Ground Truth Data)
    (Sensor & Tracking
    Data)
    Vehicle &
    Sensors
    Vehicle
    & Sensor
    Model
    Environment
    Creation
    Bridge
    Real-World
    User modules
    Third Party
    Collaboration
    LGSVL
    Simulator
    Test Scenario Scenario Player
    3rd party
    Test Scenario
    3rd party
    ScenarioPlayer
    HD Map
    

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48. 48 Build Software to Test Software exactpro.com
    Bridges for Connecting to Driverless Vehicles
    

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49. 49 Build Software to Test Software exactpro.com
    Real
    Road
    Testing
    Simulation
    Python API
    Analytics & Visualization
    Logs Logs
    AD Stack
    Simulator
    Plugins
    Digital Twin Map (or
    Procedurally Generated Map)
    (Ground Truth Data)
    (Sensor & Tracking
    Data)
    Vehicle &
    Sensors
    Vehicle
    & Sensor
    Model
    Environment
    Creation
    Bridge
    Real-World
    User modules
    Third Party
    Collaboration
    LGSVL
    Simulator
    Test Scenario Scenario Player
    3rd party
    Test Scenario
    3rd party
    Scenario Player
    HD Map
    LGSVL Simulator and its APIs
    

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50. 50 Build Software to Test Software exactpro.com
    https://www.lgsvlsimulator.com/docs/python-api/
    LGSVL Simulator and its APIs
    

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51. 51 Build Software to Test Software exactpro.com
    https://www.lgsvlsimulator.com/docs/python-api/
    LGSVL Simulator and its APIs
    

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52. 52 Build Software to Test Software exactpro.com
    https://github.com/lgsvl/PythonAPI
    LGSVL Simulator and its APIs
    

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53. 53 Build Software to Test Software exactpro.com
    https://github.com/lgsvl/PythonAPI/blob/master/quickstart/01-connecting-to-simulator.py
    LGSVL Simulator and its APIs
    

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54. 54 Build Software to Test Software exactpro.com
    Connection via port 8181
    

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55. 55 Build Software to Test Software exactpro.com
    Simulator’s response
    

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56. 56 Build Software to Test Software exactpro.com
    Request
    

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57. 57 Build Software to Test Software exactpro.com
    Response
    

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58. 58 Build Software to Test Software exactpro.com
    Callbacks
    Python API Simulator
    Simulation
    In running
    Python code waits
    for response
    Other
    actions
    Connect websocket
    Create vehicle
    Create pedestrian
    sim.run()
    Time limit or callback (ex collision)
    Create “Simulator”
    

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59. 59 Build Software to Test Software exactpro.com
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