main.js

const couch_ = module.exports = {}

couch_.mapResult = (res, type) => res.rows.map(row => row[type])
couch_.mapDoc = res => couch_.mapResult(res, 'doc')
couch_.mapId = res => res.rows.map(row => row.id)
couch_.mapValue = res => res.rows.map(row => row.value)
couch_.mapValueId = res => res.rows.map(row => row.value._id)

couch_.firstDoc = docs => docs != null ? docs[0] : null

couch_.joinOrderedIds = function (idA, idB) {
  if (idA < idB) return `${idA}:${idB}`
  else return `${idB}:${idA}`
}

couch_.ignoreNotFound = err => {
  if (!(err && err.error === 'not_found')) throw err
}

couch_.getObjIfSuccess = (db, body) => {
  if ((db.get != null) && body.ok) {
    return db.get(body.id)
  } else if (db.get != null) {
    throw new Error(`${body.error}: ${body.reason}`)
  } else {
    throw new Error('bad db object passed to _.getObjIfSuccess')
  }
}