Convert String to Object for the Slug Type

import { studioClient } from './studioClient';
import cq from 'concurrent-queue';

// Create a queue to limit the rate at which you write changes to Sanity
let queue = cq()
  .limit({ concurrency: 2 })
  .process((task) => {
    return new Promise(function (resolve, reject) {
      setTimeout(resolve.bind(undefined, task), 1000);
    });
  });

const mutateDocs = async () => {
  //Fetch the documents you need to mutate
  const query = `*[defined(slug)]`;
  const docs = await studioClient.fetch(query);
  // Loop through all of the docs returned from our query
  for (const doc of docs) {
    queue(doc).then(async () => {
      // Add a message to help us know the upload is happening
      console.log(`Mutating ${doc._id}`);
      // Tell the client to patch the current document
      studioClient
        .patch(doc._id)
        // Set the field
        .set({
          slug: {
            _type: 'slug',
            current: doc.slug
          }
        })
        .commit()
        .then((updatedDoc) =>
          console.log(`Hurray, the doc is updated! New document:`, updatedDoc)
        )
        .catch((err) =>
          console.error('Oh no, the update failed: ', err.message)
        );
    });
  }
};

mutateDocs();

sanity exec <path-to-script> --withUserToken

import { studioClient } from './studioClient';

import client from 'part:@sanity/base/client';