nedb/test/cursor.test.js

var should = require('chai').should()
  , assert = require('chai').assert
  , testDb = 'workspace/test.db'
  , fs = require('fs')
  , path = require('path')
  , _ = require('underscore')
  , async = require('async')
  , model = require('../lib/model')
  , Datastore = require('../lib/datastore')
  , Persistence = require('../lib/persistence')
  , Cursor = require('../lib/cursor')
  ;


describe.only('Cursor', function () {
  var d;

  beforeEach(function (done) {
    d = new Datastore({ filename: testDb });
    d.filename.should.equal(testDb);
    d.inMemoryOnly.should.equal(false);

    async.waterfall([
      function (cb) {
        Persistence.ensureDirectoryExists(path.dirname(testDb), function () {
          fs.exists(testDb, function (exists) {
            if (exists) {
              fs.unlink(testDb, cb);
            } else { return cb(); }
          });
        });
      }
    , function (cb) {
        d.loadDatabase(function (err) {
          assert.isNull(err);
          d.getAllData().length.should.equal(0);
          return cb();
        });
      }
    ], done);
  });
  
  describe('Sorting of the results', function () {
  
    it('Using one sort', function (done) {
      var cursor, i;
      
      d.insert({ age: 5 });
      d.insert({ age: 57 });
      d.insert({ age: 52 });
      d.insert({ age: 23 });
      d.insert({ age: 89 }, function (err) {   // We only need the last callback as all operations are queued
        cursor = new Cursor(d, {});
        cursor.sort({ age: 1 });
        cursor.exec(function (err, docs) {
          assert.isNull(err);
          // Results are in ascending order
          for (i = 0; i < docs.length - 1; i += 1) {
            assert(docs[i].age < docs[i + 1].age)
          }
          
          cursor.sort({ age: -1 });
          cursor.exec(function (err, docs) {
            assert.isNull(err);
            // Results are in descending order
            for (i = 0; i < docs.length - 1; i += 1) {
              assert(docs[i].age > docs[i + 1].age)
            }
          
            done();
          });          
        });
      });
    });
  
  });
  
});