Apply immer patches loosely to an object, in case the object doesn't match the object which the patches were created against in the first place.

looseApplyPatches.ts

import { produce, applyPatches, enablePatches } from "immer";

enablePatches();

function setToValue(obj, value, path) {
  var i;
  path = path.split(".");
  for (i = 0; i < path.length - 1; i++) {
    if (!obj[path[i]]) {
      obj[path[i]] = isNaN(parseInt(path[i], 10)) ? {} : [];
    }
    obj = obj[path[i]];
  }

  obj[path[i]] = value;
}
                             
function looseApplyPatches(startingState, patches) {
  try {
    return applyPatches(startingState, patches);
  } catch (err) {
    if (err.message.includes("Cannot apply patch, path doesn't resolve: ")) {
      const path = err.message.split(": ")[1];
      const objPath = path.split("/").join(".");
      const newStartingState = { ...startingState };
      setToValue(newStartingState, undefined, objPath);
      return looseApplyPatches(newStartingState, patches);
    }
    throw err
  }
}

Usage:

const data = { a: { c: 4, d: 5, e: [1, 2, 3] }, b: 2 };
let patchList;

const newData = produce(
  data,
  draft => {
    draft.a.c = 6;
    draft.a.e.push("6");
    draft.b = true;
    draft.c = "awesome";
  },
  patches => {
    patchList.push(patches);
  }
);

const missingData = { b: 2 };
const newState = looseApplyPatches(missingData, patchList);
console.log(newState)