Query middleware not executed when using cursor

[zoellner]

Not sure if it is a bug or by design, but query middleware is ignored for .cursor() calls. If it's by design it should be mentioned in the docs.

Expected behavior would be the same query for either call.
Current behavior is (with test script below):
find(): Mongoose: tests.find({ b: true }, { fields: {} })
find().cursor(): Mongoose: tests.find({ isB: true }, { retainKeyOrder: false, fields: {} })

'use strict';

const mongoose = require('mongoose');

mongoose.connect('mongodb://localhost/github-mongoose-query-middleware-cursor', {});
mongoose.set('debug', true);

const TestSchema = new mongoose.Schema({a: {type: String}, b: {type: Boolean}});

const queryMiddleware = function() {
  if (this._conditions.hasOwnProperty('isB')) {
    this._conditions.b = this._conditions.isB;
    delete this._conditions.isB;
  }
};

TestSchema.pre('find', queryMiddleware);
TestSchema.pre('findOne', queryMiddleware);
TestSchema.pre('count', queryMiddleware);

const Test = mongoose.model('Test', TestSchema);

const query = { user: { $type: 'string' } };

Test.insertMany([{a: 'b true', b: true}, {a: 'b false', b: false}], function (err) {
  if (err) {console.error(err);}
  Test.find({isB: true}).exec(function(err, t) {
    if (err) {console.error(err);}
    console.log(t);

    let cursor = Test.find({isB: true}).cursor();
    process.exit();
  });
});

using
node.js v6.9.5
mongoose v4.9.1
mongodb v3.4.1

[sobafuchs]

@zoellner thanks for the clear repro script, this looks like a bug

[joniba]

is there a workaround for those of us that cannot upgrade right now to a version with the fix?

[vkarpov15]

@joniba not currently. What version are you on and what prevents you from upgrading to 4.9.2?