reconcile

Returns a draft-mutating function that smart-merges value into a store, preserving the identity of items whose key field matches between old and new states. Useful when applying server payloads or full-replacement data onto an existing store without losing fine-grained reactivity.

Items with the same key are updated in place (only changed properties trigger updates). Items added or removed update the corresponding signals.

Import

import { reconcile } from "solid-js";

Type signature

function reconcile<T extends U, U>(
  value: T,
  key: string | ((item: NonNullable<any>) => any)
);

Parameters

value

The next state to merge in

key

Property name (string) or extractor function for stable identity

Examples

const [todos, setTodos] = createStore<Todo[]>([]);

async function refresh() {
  const fresh = await api.getTodos();
  setTodos(reconcile(fresh, "id")); // diff-merge by `id`
}