memcached/test/memcached-cas.test.js

A fully featured Memcached API client, supporting both single and clustered Memcached servers through consistent hashing and failover/failure. Memcached is rewrite of nMemcached, which will be deprecated in the near future.

'use strict';

/**
 * Test dependencies
 */
var assert = require('assert')
  , common = require('./common')
  , Memcached = require('../');

global.testnumbers = global.testnumbers || +(Math.random(10) * 1000000).toFixed();

/**
 * Expresso test suite for all `get` related
 * memcached commands
 */
describe('Memcached CAS', function () {
  /**
   * For a proper CAS update in memcached you will need to know the CAS value
   * of a given key, this is done by the `gets` command. So we will need to make
   * sure that a `cas` key is given.
   */
  it('set and gets for cas result', function (done) {
    var memcached = new Memcached(common.servers.single)
        , message = common.alphabet(256)
        , testnr = ++global.testnumbers
        , callbacks = 0;

      memcached.set('test:' + testnr, message, 1000, function (error, ok) {
        ++callbacks;

        assert.ok(!error);
        ok.should.be.true;

        memcached.gets('test:' + testnr, function (error, answer) {
          ++callbacks;

          assert.ok(!error);

          assert.ok(typeof answer === 'object');
          assert.ok(!!answer.cas);
          answer['test:' + testnr].should.eql(message);

          memcached.end(); // close connections
          assert.equal(callbacks, 2);
          done();
        });
      });
  });

  /**
   * Create a successful cas update, so we are sure we send a cas request correctly.
   */
  it('successful cas update', function(done) {
    var memcached = new Memcached(common.servers.single)
        , message = common.alphabet(256)
        , testnr = ++global.testnumbers
        , callbacks = 0;

      memcached.set('test:' + testnr, message, 1000, function (error, ok) {
        ++callbacks;
        assert.ok(!error);
        ok.should.be.true;

        memcached.gets('test:' + testnr, function (error, answer) {
          ++callbacks;
          assert.ok(!error);
          assert.ok(!!answer.cas);

          // generate new message for the cas update
          message = common.alphabet(256);
          memcached.cas('test:' + testnr, message, answer.cas, 1000, function (error, answer) {
            ++callbacks;
            assert.ok(!error);
            assert.ok(!!answer);

            memcached.get('test:' + testnr, function (error, answer) {
              ++callbacks;

              assert.ok(!error);
              answer.should.eql(message);

              memcached.end(); // close connections
              assert.equal(callbacks, 4);
              done();
            });
          });
        });
      });
  });

  /**
   * Create a unsuccessful cas update, which would indicate that the server has changed
   * while we where doing nothing.
   */
  it('unsuccessful cas update', function (done) {
     var memcached = new Memcached(common.servers.single)
        , message = common.alphabet(256)
        , testnr = ++global.testnumbers
        , callbacks = 0;

      memcached.set('test:' + testnr, message, 1000, function (error, ok) {
        ++callbacks;
        assert.ok(!error);
        ok.should.be.true;

        memcached.gets('test:' + testnr, function (error, answer) {
          ++callbacks;
          assert.ok(!error);
          assert.ok(!!answer.cas);

          // generate new message
          message = common.alphabet(256);
          memcached.set('test:' + testnr, message, 1000, function () {
            ++callbacks;

            memcached.cas('test:' + testnr, message, answer.cas, 1000, function (error, answer) {
              ++callbacks;
              assert.ok(!error);
              assert.ok(!answer);

              memcached.get('test:' + testnr, function (error, answer) {
                ++callbacks;

                assert.ok(!error);
                answer.should.eql(message);

                memcached.end(); // close connections
                assert.equal(callbacks, 5);
                done();
              });
            });
          });
        });
      });
  });
});