Underscores to camelCase conversion and type inference (camelcase-keys, zod)

Scene.ts

import { z } from "zod"
import camelcaseKeys from "camelcase-keys"

export const SceneSchema = z
  .object({
    id: z.string().optional(),
    movieId: z.string(),
    type: z.string(),
  })
  .transform((item) => {
    return {
      ...item,
      toJson: () => {
        return Object.fromEntries(
          Object.entries(item).map(([key, value]) => [
            key.replace(/([A-Z])/g, "_$1").toLowerCase(),
            value,
          ]),
        )
      },
    }
  })

export type Scene = z.infer<typeof SceneSchema> & {
  toJson(): Object
}

export const createScene = (data: Record<string, unknown>): Scene => {
  return SceneSchema.parse(camelcaseKeys(data, { deep: true }))
}