sanity/src/core/form/store/stateTreeHelper.ts

Sanity is a real-time content infrastructure with a scalable, hosted backend featuring a Graph Oriented Query Language (GROQ), asset pipelines and fast edge caches

import {isKeySegment, type Path} from '@sanity/types'

import {type StateTree} from './types'

/** @internal */
export function setAtPath<T>(
  currentTree: StateTree<T> | undefined,
  path: Path,
  value: T,
): StateTree<T> {
  if (path.length === 0) {
    return {...(currentTree || {}), value}
  }
  const [head, ...tail] = path
  const key = isKeySegment(head) ? head._key : String(head)
  const children = currentTree?.children ?? {}
  return {
    value: currentTree?.value,
    children: {...children, [key]: setAtPath(children[key] || {}, tail, value)},
  }
}