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/** * Test dependencies. */
'use strict';
const start = require('./common');
const Aggregate = require('../lib/aggregate');const assert = require('assert');const random = require('./util').random;
const mongoose = start.mongoose;const Schema = mongoose.Schema;
/** * Setup. */
const userSchema = new Schema({  name: String,  age: Number});
describe('model aggregate', function() {  this.timeout(4500);
  const group = { $group: { _id: null, maxAge: { $max: '$age' } } };  const project = { $project: { maxAge: 1, _id: 0 } };  let db, A, maxAge;
  let mongo26_or_greater = false;
  before(async function() {    db = start();    A = db.model('Test', userSchema);
    const authors = 'guillermo nathan tj damian marco'.split(' ');    const num = 10;    const docs = [];    maxAge = 0;

    for (let i = 0; i < num; ++i) {      const age = Math.random() * 100 | 0;      maxAge = Math.max(maxAge, age);      docs.push({ author: authors[i % authors.length], age: age });    }
    await A.create(docs);
    const version = await start.mongodVersion();
    mongo26_or_greater = version[0] > 2 || (version[0] === 2 && version[1] >= 6);
    if (!mongo26_or_greater) {      console.log('not testing mongodb 2.6 features');    }  });
  after(async function() {    await db.close();  });
  describe('works', function() {    it('when return promise', async function() {      const res = await A.aggregate([group, project]);
      assert.ok(res);      assert.equal(1, res.length);      assert.ok('maxAge' in res[0]);      assert.equal(maxAge, res[0].maxAge);    });
    it('with arrays', async function() {      const res = await A.aggregate([group, project]);
      assert.ok(res);      assert.equal(res.length, 1);      assert.ok('maxAge' in res[0]);      assert.equal(res[0].maxAge, maxAge);    });
    it('with Aggregate syntax', async function() {      const res = await A.aggregate()        .group(group.$group)        .project(project.$project)        .exec();
      assert.ok(res);      assert.equal(res.length, 1);      assert.ok('maxAge' in res[0]);      assert.equal(res[0].maxAge, maxAge);    });
    it('with Aggregate syntax if callback not provided', async function() {      const promise = A.aggregate()        .group(group.$group)        .project(project.$project)        .exec();
      const res = await promise;
      assert.ok(promise instanceof mongoose.Promise);      assert.ok(res);      assert.equal(res.length, 1);      assert.ok('maxAge' in res[0]);      assert.equal(maxAge, res[0].maxAge);    });
    it('when returning Aggregate', function() {      assert(A.aggregate([project]) instanceof Aggregate);    });
    it('throws when passing object (gh-6732)', function() {      assert.throws(() => A.aggregate({}), /disallows passing a spread/);    });
    it('can use helper for $out', async function() {      if (!mongo26_or_greater) {        return;      }
      const outputCollection = 'aggregate_output_' + random();      await A.aggregate()        .group(group.$group)        .project(project.$project)        .out(outputCollection)        .exec();
      const documents = await A.db.collection(outputCollection).find().toArray();
      assert.equal(documents.length, 1);      assert.ok('maxAge' in documents[0]);      assert.equal(maxAge, documents[0].maxAge);    });  });});