a-smaller-1.js

const generateQuery = (params) => {
  const query = {}

  try {
    if (params.email) {
      const isValid = isValidEmail(params.email)
      if (isValid) {
        query.email = params.email
      }
    }

    const defaultMaxAgeLimit = JSON.parse(localStorage.getItem('defaultMaxAgeLimit') || '')
    if (params.maxAge) {
      if (params.maxAge < 25) {
        query.maxAge = params.maxAge
      }
    } else {
      query.maxAge = defaultMaxAgeLimit
    }

    if (params.limit) {
      query.limit = params.limit
    }

    // do a lot of things here
    // ...

  } catch(err) {
    // error handing
  }

  return query
}