mongoing/index.js

cloud function computing mongodb middleware

'use strict'

const { connect } = require('mongodb')

/**
 * url
 * process.env.MONGODB
 * mongodb://127.0.0.1:27017/mongoing
 */
module.exports = function (callback, url, options = {}) {
    let collections = []
    let mongourl = typeof url === 'string' ? url :
        (process.env.MONGODB || 'mongodb://127.0.0.1:27017/mongoing')
    if (url instanceof Array) {
        collections = url
    } else if (options instanceof Array) {
        collections = options
    }
    options = Object.assign({
        useNewUrlParser: true,
        useUnifiedTopology: true
    }, options instanceof Array ? {} : options)

    return async (...args) => {
        let __client = null
        let __db = null
        try {
            __client = await connect(mongourl, options)
            __db = __client.db()
            let list = await __db.collections()
            const collectionMap = {}
            list.forEach(i => collectionMap[i.collectionName] = i)
            for (let name of collections) {
                if (!collectionMap[name]) {
                    collectionMap[name] = __db.collection(name)
                }
            }
            const result = await callback(...args, { __client, __db, ...collectionMap })
            return result
        } catch (err) {
            throw err
        } finally {
            __client && await __client.close()
        }
    }
}