Finding references to a deprecated component in Sanity schemas and documents.

{
title: 'body',
type: 'array',
of: [
 { type: block, .... },
 { type: 'custom-form'},
 { ... ~100 components }
]
}

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: 25 })
  .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(<name-of-field>)]`;
  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)
        // Unset the field
        .unset(['<name-of-field>'])
        // Commit the changes
        .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();

// execute this script by running
// $ sanity exec ./lib/utils/mutateDocs.js --withUserToken