[js] refaktoring, static typing, dokumentace, linter, formatter

[rodlukas]

Refaktoring

• sjednotit rozhrani, promenne a metody komponent, napr. někde se nejdřív po uložení dá close, někde refresh; casto se props jmenuji jinak, nekdy ve functional komponente se preda prop, nekdy se rovnou props vyjmenuji, nesedi pojmenovani promennych (isLoaded vs IS_LOADING - rozdil ve vyznamu i zpusobu zapisu...)
• zavest PureComponent a React.memo, viz:
  • https://reactjs.org/docs/optimizing-performance.html
  • https://blog.logrocket.com/immutability-in-react-ebe55253a1cc/
  • https://reactjs.org/blog/2018/09/10/introducing-the-react-profiler.html
  • https://github.com/welldone-software/why-did-you-render
  • https://blog.opendigerati.com/taking-control-of-react-performance-4f21a15a19b5
  • https://github.com/facebook/react/blob/master/packages/react-devtools/CHANGELOG.md)
  • upravit onChange={ (e) => this.handleOnChange(e) } ?
• odstraneni zbytecnych konstruktoru, zavedeni class properties
• hooky (https://habr.com/en/post/443500/ / https://overreacted.io/a-complete-guide-to-useeffect/)
• odstraneni kontruktoru

Linter, formatter

• zavest ESlint
• vhodna konfigurace ESlint
• zavest code formatting

Dokumentace + static typing

• [X] zavest Flow
• [ ] prevest vsechny komponenty frontendu na Flow - na flow ne, spousta issues, mala komunita, strasna podpora IDE - s flow se ceka na opravu https://youtrack.jetbrains.com/issue/WEB-40710?p=PY-37481 NEBO TS? -> jo, TS
• migrace na Typescript - migrace cele codebase na TS, vyladeni workflow, sladeni s ostatnimi pouzivanymi nastroji (eslint, babel...)
• dokumentovat vse krome src/components a src/forms/helpers
• dokumentovat src/components a src/forms/helpers
• prevest interface na type, viz https://medium.com/@martin_hotell/10-typescript-pro-tips-patterns-with-or-without-react-5799488d6680, https://github.com/typescript-cheatsheets/react-typescript-cheatsheet#types-or-interfaces, https://medium.com/@koss_lebedev/type-aliases-vs-interfaces-in-typescript-based-react-apps-e77c9a1d5fd0

Další

• zavest React Strict Mode, ale az bude spraveno StrictMode warning for findDOMNode and legacy context API in Transition as of React 16.6 reactjs/react-transition-group#429