dbPath.ts

dbPath.ts

type PathConfig = { [key: string]: PathConfig }

type Collection<T extends PathConfig> = ((id?: string) => string) & {
  [K in keyof T]: Collection<T[K]> & ((id?: string) => string)
}

function collection<T extends PathConfig>(
  basePath: string,
  name: string,
  subCollections?: T
): Collection<T> {
  const newPath = basePath + (name ? '/' + name : '')

  const handler = {
    apply: (target: any, thisArg: any, argArray?: any) => {
      return newPath + (argArray[0] ? '/' + argArray[0] : '')
    },
    get: (target: any, property: string) => {
      if (property in target) {
        return target[property]
      }
      if (subCollections && property in subCollections) {
        target[property] = collection(
          newPath,
          property,
          subCollections[property]
        )
        return target[property]
      }
      if (typeof property === 'string') {
        target[property] = collection(newPath, property)
        return target[property]
      }
      return undefined
    },
  }

  return new Proxy(() => {}, handler) as Collection<T>
}

const dbPath = collection('', '', {
  workspaces: {
    accounts: {},
    categories: {
      subcategories: {},
    },
    transactions: {},
  },
})

dbPath.workspaces() /*?*/
dbPath.workspaces('asdf') /*?*/
dbPath.workspaces['w1'].categories() /*?*/