Search a JavaScript object for a string

ob-search.js

function search(ob, needle, path = [], seen = new Map()) {
  if (seen.has(ob)) {
    return
  }
  seen.set(ob, true)

  for (const key of Object.keys(ob)) {
    if (typeof ob[key] === 'string') {
      if (ob[key].indexOf(needle) !== -1) {
        const pathDesc = [...path, key].map(pathKey => Number(pathKey) == pathKey ? `[${pathKey}]` : `.${pathKey}`).join('').substring(1)
        console.log(`Found needle ${pathDesc} = ${ob[key]}`)
      }
    } else if (typeof ob[key] === 'object' && ob[key]) {
      search(ob[key], needle, [...path, key], seen)
    }
  }
}