src/deps/safeJsonParse.js

import vuvuzela from 'vuvuzela';

function slowJsonParse(str) {
  try {
    return JSON.parse(str);
  } catch (e) {
    /* istanbul ignore next */
    return vuvuzela.parse(str);
  }
}

function safeJsonParse(str) {
  // try/catch is deoptimized in V8, leading to slower
  // times than we'd like to have. Most documents are _not_
  // huge, and do not require a slower code path just to parse them.
  // We can be pretty sure that a document under 50000 characters
  // will not be so deeply nested as to throw a stack overflow error
  // (depends on the engine and available memory, though, so this is
  // just a hunch). 50000 was chosen based on the average length
  // of this string in our test suite, to try to find a number that covers
  // most of our test cases (26 over this size, 26378 under it).
  if (str.length < 50000) {
    return JSON.parse(str);
  }
  return slowJsonParse(str);
}

export default safeJsonParse;