Interactive implementation in TypeScript

Whether it's a good practice or not, take note of the steps.

• I want to implement spitting out the selection to JSON.
• I'd like to try things out interactively before deciding how to implement them.
• Where is the selection?
  • const App = (props: any) => {...} In the .
    • let [selection, setSelection] = useState<PaperItem[]>([]);
  • Not exposed because of the local scope of the function.
  • Expose with window.debug.selection = selection;.
    • Related: Add a new property to the window with TypeScript.
    • window.debug is prepared with the type "any" so that you don't have to declare it every time.
    • Or @ts-ignore.
• Where is the code to convert an object to a plain object
  • const stateItemToFirestore = (x: StateItem) => {...}
  • This is also after the function definition window.debug.stateItemToFirestore = stateItemToFirestore...
    • I was going to, but ng.
      • Since the code for this function definition runs before the code that creates window.debug
  • export stateItemToFirestore.
    • On the side of the code making window.debug, import it to expose
    • Considerations on how to expose objects
• succession
  • window.debug.stateItemToFirestore(window.debug.selection)
    • error
  • window.debug.stateItemToFirestore(window.debug.selection[0])
    • error
  • window.debug.stateItemToFirestore(window.debug.selection[0]).item
    • OK
  • This is the wrong argument type to call.
    • If I had written it as TypeScript, would I have found out why with a type error?
    • -> NO, type information is lost when you put it in `window.debug:any
  • JSON.stringify(...)
    • The desired string is obtained.
  • Next step is to figure out how to get this back to Map.
• Expose the updateStateItem as it is exported.
  • →Error in simple reading
• Requires firestoreToStateItem.
  • It's done.
  • 
• Make it TypeScript code. ts

export const exportSelectedItemsAsJSON = () => {
  const r = selectedItems.map((x) =>
    stateItemToFirestore(x.item)
  );
  return JSON.stringify(r);
};

export const importItemsFromJSON = (json: string) => {
  const xs = JSON.parse(json);
  xs.forEach((x: object) => {
    updateStateItem(null, firestoreToStateItem(x))
  })
};

• Now it works as expected: debug.importItemsFromJSON(debug.exportSelectedItemsAsJSON())
• But copying and pasting the JSON displayed in the console with debug.exportSelectedItemsAsJSON() breaks it.
  • Well, it's no wonder JSON doesn't parse correctly in the developer console.
• localStorage["tmp"] = debug.exportSelectedItemsAsJSON()
• In a separate window debug.importItemsFromJSON(localStorage["tmp"])
• It worked correctly.

This page is auto-translated from /nishio/TypeScriptで対話的に実装 using DeepL. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at @nishio_en. I'm very happy to spread my thought to non-Japanese readers.