The Hitchhiker's Guide to Servo Contributor

Transcript

1. The Hitchhiker’s Guide to
   Servo Contributor
   @_cybai, HERP, Inc.
   Rust.Tokyo
   

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2. whoami
   ● Haku
   ● @CYBAI
   ● @_cybai
   ● Software Engineer @ HERP, Inc.
   ● Contribute to Servo from Aug 2017
   2
   

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3. ● What is Servo?
   ● How to contribute?
   ● How to run tests?
   ● How Servo CI works?
   Agenda
   3
   

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4. ● What is Servo?
   ● How to contribute?
   ● How to run tests?
   ● How Servo CI works?
   Agenda
   4
   

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5. ● A modern, high-performance greenfield browser
   engine designed for both application and
   embedded use
   ● Written in Rust
   ● Aim to achieve parallel and concurrency
   computing and layout
   ● Derived memory safety and security from Rust
   What is Servo?
   5
   

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6. What is Servo? (Cont.)
   ● Two successful components have been migrated into
   Firefox, e.g. Stylo and WebRender
   6
   

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7. Demo
   7
   

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8. ● What is Servo?
   ● How to contribute?
   ● How to run tests?
   ● How Servo CI works?
   Agenda
   8
   

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9. Workflow
   9
   Find
   issue
   Implementation
   Test related
   WPT locally
   Send /
   Update
   PR
   Review
   PR merged
   Run
   CI
   passed with r+
   Check
   Failures
   : Sucess
   : Failure
   

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10. How to get involved?
    ● Check E-* labels
    ○ E stands for Effort here.
    ○ E-easy and E-less easy are good for new contributors.
    ○ E-candidate-for-mentoring means it might be an easy
    issue because members didn’t check it carefully. But, they
    will mentor you to finish the issue.
    ○ E-hard means challenging tasks.
    10
    Ref: Tag label names and definitions
    

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11. How to get involved? (Cont.)
    ● Check the Servo starter page.
    ● Find any Web API you’re interested in and it’s missing
    or implemented incorrectly in Servo!
    11
    

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12. 12
    The first issue I fixed
    

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13. 13
    From WHATWG DOM spec
    

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15. 15
    But, how can I confirm my
    implementation is correct?
    

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16. ● What is Servo?
    ● How to contribute?
    ● How to run tests?
    ● How Servo CI works?
    Agenda
    16
    

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17. WPT
    ● In Software Engineering, writing tests to
    verify our business logic is indispensable.
    ● So do the web platforms!
    ● Here comes the Web Platform Tests a.k.a
    wpt.
    17
    

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18. “The web-platform-tests project is a W3C-coordinated
    attempt to build a cross-browser test suite for the
    Web-platform stack.”
    -- web-platform-tests.org
    What is wpt?
    18
    

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19. Brief introduction to WPT metadata
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20. How to run tests with Servo CI?
    20
    Ask @bors-servo to trigger “try” tests
    

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21. How to run tests with Servo CI? (Cont.)
    21
    CI tests triggered by try will report tests result
    when all tests passed instead of merging PR
    

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22. How to run tests with Servo CI? (Cont.)
    22
    But wait! Let’s see what @jdm said!
    
    

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23. How to run tests with Servo CI? (Cont.)
    23
    

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24. WPT Synchronization
    24
    Sync new /
    fixed tests
    Contribute new
    / fixed tests
    

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25. 25
    After upstream tests synced
    and try again, finally got
    unexpected PASS!
    

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26. 26
    Approved by @jdm after the tests marked as PASS
    

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27. But wait! Why not just merge the PR? and what exactly is
    @bors-servo and r+?
    27
    
    

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28. ● What is Servo?
    ● How to contribute?
    ● How to run tests?
    ● How Servo CI works?
    Agenda
    28
    

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29. Homu: The Not Rocket Science™
    bors is first introduced by Graydon Hoare who is Rust’s original
    creator and mainly applied Ben Elliston’s “not rocket science”
    rule to the bot:
    29
    The Not Rocket Science Rule Of Software Engineering:
    automatically maintain a repository of code that always passes all the tests
    -- Ben Elliston
    

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30. Homu: The Not Rocket Science™
    30
    Rename fn foo → fn bar
    ✅ CI Pass
    Call fn foo in somewhere
    ✅ CI Pass
    ☠ Function foo doesn’t exist
    ❌ Broken master branch
    A B
    

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31. Homu: The Not Rocket Science™
    31
    Screenshot from Homu Queue
    

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32. 32
    @bors-servo with r+ merged PR after
    CI passed
    

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33. Recap
    33
    

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34. Recap
    34
    Write
    spec
    compliant
    tests
    Implement
    existing
    /
    new
    spec
    
    Contribute new / fixed tests
    

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35. Recap
    35
    
    Add
    /
    fix
    tests
    while
    changed
    
    Contribute
    spec
    bugfix
    or
    new
    feature
    Sync new / fixed tests
    

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36. References
    ● Experience Report: Developing the Servo Web Browser Engine
    using Rust
    ● technicalities: "not rocket science" (the story of monotone and bors)
    ● Rust infrastructure can be your infrastructure
    ● Servo: Designing and Implementing a Parallel Browser
    ● Servo and YOU: A beginner's guide
    ● Inside a super fast CSS engine: Quantum CSS (aka Stylo)
    ● The whole web at maximum FPS: How WebRender gets rid of jank
    36
    

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37. 37
    https://blog.cybai.dev/
    References
    

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38. Q & A ?
    38
    We’re hiring!
    

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39. Thank you!
    @_cybai
    39
    

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