memory adapter can report incorrect total_rows

[alxndrsn]

Browser: webkit

Observed

There appears to be a race condition in pouchdb-adapter-memory which means that the result of allDocs() can sometimes return a different value for total_rows vs result.rows.length.

Expected

Calling db.allDocs() without args should return a .rows array prop with length equal to returned .total_rows value.

Example

build: https://github.com/pouchdb/pouchdb/actions/runs/8567263981/job/23559252499

logs

   1 failing

  1) test.all_docs.js-http
       test total_rows with a variety of criteria * 100:

      correctly return total_rows
      + expected - actual

      -801
      +800
      
  @http://127.0.0.1:8000/tests/integration/test.all_docs.js:489:36

Test Code

        return db.allDocs();
      }).then(function (res) {
        res.rows.should.have.length(800,  'correctly return rows');
        res.total_rows.should.equal(800,  'correctly return total_rows');

[alxndrsn]

This actually appears to be running against the server defined in tests/misc/express-pouchdb-minimum-for-pouchdb.js:

'use strict';

var PouchDB = require('../../');

var app = require('express-pouchdb')(PouchDB, {
  mode: 'minimumForPouchDB'
});
app.listen(3000);

https://www.npmjs.com/package/express-pouchdb aka https://github.com/pouchdb/pouchdb-server

Ref #8884