A test case that produces conflicts, and then performs a mango query that should find only the conflicts, but also reports documents without conflicts.

test-conflict-index.js

#!/usr/bin/env node
'use strict'

/**
 * A test case that produces conflicts,
 * and then performs a mango query that
 * should find only the conflicts, but also
 * reports documents without conflicts.
 *
 * To run this script:
 * $ mkdir test-conflict-index && cd $_
 * $ curl https://gist.githubusercontent.com/garbados/335bc7c1836cbf726a6b511d6c0fa418/raw/c82d3f151c829449019bc0ec09ba77363d7f6b99/test-conflict-index.js test.js
 * $ npm i async request
 * $ node test.js
 *
 * Here are the approximate steps taken by the script:
 *
 * - add a document to one db
 * - add a different document to the other
 * - replicate it to the other
 * - update the document on each db, but differently
 * - replicate one to the other
 * - now there is a conflict!
 * - perform _find query
 * - verify that it returns >1 doc
 */

const async = require('async')
const request = require('request')
const url = require('url')

const COUCH_URL = url.parse(process.env.COUCH_URL)
const SELECTOR = {
  selector: { _id: { $exists: true } },
  conflicts: true
}

// helper for turning [host, db, doc] into host/db/doc
const cJoin = function () {
  const args = Object.values(arguments)
  var href = COUCH_URL.href
  if (href.slice(-1)[0] === '/') href = href.slice(0, -1)
  return [href].concat(args).join('/')
}

var options = {
  dbs: ['x', 'y'],
  docs: [{ _id: 'a' }, { _id: 'b' }],
  updates: [{ c: 'd' }, { d: 'e' }],
  revs: []
}

function tearDown (done) {
  async.times(2, function (i, done) {
    var db = options.dbs[i]
    request({
      url: cJoin(db),
      method: 'DELETE'
    }, done)
  }, done)
}

async.series([
  // create two databases with one document each
  async.times.bind(async, 2, function (i, done) {
    var db = options.dbs[i]
    var doc = options.docs[i]
    async.series([
      request.bind(request, {
        url: cJoin(db),
        method: 'PUT'
      }),
      request.bind(request, {
        url: cJoin(db, doc._id),
        method: 'PUT',
        json: doc
      })
      // TODO collect doc results, add _rev to options.revs
    ], function (err, result) {
      if (err) return done(err)
      doc._rev = result[1][1].rev
      return done()
    })
  }),
  // replicate one to the other
  function (done) {
    request({
      url: cJoin('_replicate'),
      method: 'POST',
      json: {
        source: options.dbs[0],
        target: options.dbs[1]
      }
    }, done)
  },
  // update the documents on each
  async.times.bind(async, 2, function (i, done) {
    var db = options.dbs[i]
    var doc = options.docs[0]
    var update = options.updates[i]
    request({
      url: cJoin(db, doc._id),
      method: 'PUT',
      json: Object.assign({}, doc, update)
    }, done)
  }),
  // replicate again, creating the conflict
  function (done) {
    request({
      url: cJoin('_replicate'),
      method: 'POST',
      json: {
        source: options.dbs[0],
        target: options.dbs[1]
      }
    }, done)
  },
  async.waterfall.bind(async, [
    // perform the _find query
    request.bind(request, {
      url: cJoin(options.dbs[1], '_find'),
      method: 'POST',
      json: SELECTOR
    }),
    // verify that not all returns docs have conflicts
    function (res, body, done) {
      const db = options.dbs[1]
      const docs = body.docs
      console.log(body)
      console.log(docs)
      console.log('CouchDB reports %i docs with conflicts', docs.length)
      console.log('  docs: %s', docs.map(doc => doc._id).join(', '))
      async.each(docs, function (doc, done) {
        request({
          url: cJoin(db, doc._id),
          qs: { conflicts: true }
        }, function (err, res, body) {
          if (err) return done(err)
          const doc = JSON.parse(body)
          console.log('Retrieved %s', doc._id)
          console.log('  doc: %j', doc)
          if (!doc._conflicts) {
            console.log('  ... but it has no conflicts!')
          }
          return done()
        })
      }, done)
    }
  ])
], function (err) {
  if (err) console.log(err)
  return tearDown()
})