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Practical Flow Type

July 14, 2017

Practical Flow Type

Slides presented at gotanda.js

Nobuhide Yayoshi


July 14, 2017

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  1. Hello! I am Nobuhide Yayoshi 弥吉修英 You can find me

    at @yayoc Frontend engineer, iOS At Fast Retailing
  2. Model Promise immutability [flow] property `username` (user.js:20:7) Covariant property `username`

    incompatible with contravariant use in assignment of property `username`
  3. Compare Typescript if you use Flow, you'll have much higher

    type coverage much faster and you'll be able to sleep soundly. http://thejameskyle.com/adopting-flow-and-typescript.html
  4. Swagger Flow Type A Swagger file has more than 8000

    lines Writing Type Definitions manually is HARD
  5. Conclusion ⊙ Utility types are useful ◦ $Exact ◦ $PropertyType

    ◦ Class ◦ Immutability ⊙ Prefer Flow than Proptypes ⊙ Prefer Generic Component ⊙ swagger-to-flowtype is useful
  6. Credits Special thanks to all the people who made and

    released these awesome resources for free: ⊙ Presentation template by SlidesCarnival ⊙ Photographs by Unsplash