Updating unknown Immutable.js Map structure

Question

My task is to update deep nested values for which I don't know the path because the data is dynamic.

Example:

const errors = Immutable.fromJS({
  clients: [
    {
      users: {
        names: ["Joseph", "John"],
        items: ["Passport", "ID"],
      },
    },
  ],
  items: {
    data: {
      codes: ["543", "765", "549"],
    },
  },
});

Desired output:

const errors = Immutable.fromJS({
  clients: [
    {
      users: {
        names: "Joseph,John",
        items: "Passport,ID",
      },
    },
  ],
  items: {
    data: {
      codes: "543,765,549",
    },
  },
});

In this case, I need to concatenate all the strings inside the nested arrays (lists). I can join the nested array, but I need to somehow get to it first. I was thinking about getting the Map nested structure, but haven't found a method for it (only for keys at the same level). Can this be done in Immutable.js? If so, how?

Answer 1

You can simply use recursivity to parse and update the lists containing strings/numbers:

 let errors = Immutable.fromJS({ clients: [ { users: { names: ["Joseph", "John"], items: ["Passport", "ID"], }, }, ], items: { data: { codes: ["543", "765", "549"], }, }, }); const update = (object) => { if (typeof object.map === 'function') { return object.map((value) => { if (Immutable.List.isList(value) && value.every((val) => ['string', 'number'].includes(typeof val)) ) { return value.join(); } return update(value); }); } return object; } errors = update(errors); console.log(errors);

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