kafka-node/test/test.partitioner.js

Client for Apache Kafka v0.8+

'use strict';

var _ = require('lodash');
var kafka = require('..');
var DefaultPartitioner = kafka.DefaultPartitioner;
var RandomPartitioner = kafka.RandomPartitioner;
var CyclicPartitioner = kafka.CyclicPartitioner;
var KeyedPartitioner = kafka.KeyedPartitioner;

function getPartitions (partitioner, partitions, count) {
  var arr = [];
  for (var i = 0; i < count; i++) {
    arr.push(partitioner.getPartition(partitions));
  }
  return arr;
}

describe('Partitioner', function () {
  describe('DefaultPartitioner', function () {
    var partitioner = new DefaultPartitioner();

    describe('#getPartition', function () {
      it('should always return the first partition', function () {
        var partitions = _.uniq(getPartitions(partitioner, [0, 1], 100));
        partitions.should.have.length(1);
        partitions.should.containEql(0);
      });
    });
  });

  describe('RandomPartitioner', function () {
    var partitioner = new RandomPartitioner();

    describe('#getPartition', function () {
      it('should return partitions within the existing ones', function () {
        var partitions = _.uniq(getPartitions(partitioner, [0, 1], 100));
        partitions.should.have.length(2);
        partitions.should.containEql(0);
        partitions.should.containEql(1);
      });
    });
  });

  describe('CyclicPartitioner', function () {
    var partitioner = new CyclicPartitioner();

    describe('#getPartition', function () {
      it('should return partitions cycling throw the existing ones', function () {
        var partitions = getPartitions(partitioner, [0, 1, 2], 6);
        partitions.should.have.length(6);
        partitions[0].should.equal(0);
        partitions[1].should.equal(1);
        partitions[2].should.equal(2);
        partitions[3].should.equal(0);
        partitions[4].should.equal(1);
        partitions[5].should.equal(2);
      });

      xit('should not modify different partitioners', function () {
        var partitioner2 = new CyclicPartitioner();
        var partitions1 = getPartitions(partitioner, [0, 1, 2], 1);
        var partitions2 = getPartitions(partitioner2, [0, 1, 2], 1);
        partitions1.should.have.length(3);
        partitions2.should.have.length(3);
        partitions1[0].should.equal(0);
        partitions2[0].should.equal(0);
      });
    });
  });

  describe('KeyedPartitioner', function () {
    var partitioner = new KeyedPartitioner();

    describe('#getPartition', function () {
      it('should return partitions based on a given key', function () {
        var partitions = [partitioner.getPartition([0, 1], '12345'), partitioner.getPartition([0, 1], '123')];
        partitions.should.have.length(2);
        partitions[0].should.equal(1);
        partitions[1].should.equal(0);
      });
    });
  });
});