budibase/packages/server/src/db/client.js

const PouchDB = require("pouchdb")
const replicationStream = require("pouchdb-replication-stream")
const allDbs = require("pouchdb-all-dbs")
const { budibaseAppsDir } = require("../utilities/budibaseDir")
const env = require("../environment")

const COUCH_DB_URL = env.COUCH_DB_URL || `leveldb://${budibaseAppsDir()}/.data/`
const isInMemory = env.NODE_ENV === "jest"

PouchDB.plugin(replicationStream.plugin)
PouchDB.adapter("writableStream", replicationStream.adapters.writableStream)

let POUCH_DB_DEFAULTS = {
  prefix: COUCH_DB_URL,
}

if (isInMemory) {
  PouchDB.plugin(require("pouchdb-adapter-memory"))
  POUCH_DB_DEFAULTS = {
    prefix: undefined,
    adapter: "memory",
  }
}

const Pouch = PouchDB.defaults(POUCH_DB_DEFAULTS)

allDbs(Pouch)

module.exports = Pouch