amqp-node/test/mux.js

An AMQP 0-9-1 (e.g., RabbitMQ) library and client.

'use strict';

var assert = require('assert');
var Mux = require('../lib/mux').Mux;
var PassThrough = require('stream').PassThrough ||
  require('readable-stream/passthrough');

var latch = require('./util').latch;
var schedule = require('./util').schedule;

function stream() {
  return new PassThrough({
    objectMode: true
  });
}

function readAllObjects(s, cb) {
  var objs = [];

  function read() {
    var v = s.read();
    while (v !== null) {
      objs.push(v);
      v = s.read();
    }
  }

  s.on('end', function () {
    cb(objs);
  });
  s.on('readable', read);

  read();
}

it('single input', function (done) {
  var input = stream();
  var output = stream();
  input.on('end', function () {
    output.end();
  });

  var mux = new Mux(output);
  mux.pipeFrom(input);

  var data = [1, 2, 3, 4, 5, 6, 7, 8, 9];
  // not 0, it's treated specially by PassThrough for some reason. By
  // 'specially' I mean it breaks the stream. See e.g.,
  // https://github.com/isaacs/readable-stream/pull/55
  data.forEach(input.write.bind(input));

  readAllObjects(output, function (vals) {
    assert.deepEqual(data, vals);
    done();
  });

  input.end();
});

it('two sequential inputs', function (done) {
  var input1 = stream();
  var input2 = stream();
  var output = stream();
  var mux = new Mux(output);
  mux.pipeFrom(input1);
  mux.pipeFrom(input2);

  var data = [1, 2, 3, 4, 5, 6, 7, 8, 9];
  data.forEach(function (v) {
    input1.write(v);
  });

  input1.on('end', function () {
    data.forEach(function (v) {
      input2.write(v);
    });
    input2.end();
  });
  input2.on('end', function () {
    output.end();
  });

  input1.end();
  readAllObjects(output, function (vs) {
    assert.equal(2 * data.length, vs.length);
    done();
  });
});

it('two interleaved inputs', function (done) {
  var input1 = stream();
  var input2 = stream();
  var output = stream();
  var mux = new Mux(output);
  mux.pipeFrom(input1);
  mux.pipeFrom(input2);

  var endLatch = latch(2, function () {
    output.end();
  });
  input1.on('end', endLatch);
  input2.on('end', endLatch);

  var data = [1, 2, 3, 4, 5, 6, 7, 8, 9];
  data.forEach(function (v) {
    input1.write(v);
  });
  input1.end();

  data.forEach(function (v) {
    input2.write(v);
  });
  input2.end();

  readAllObjects(output, function (vs) {
    assert.equal(2 * data.length, vs.length);
    done();
  });
});

it('unpipe', function (done) {
  var input = stream();
  var output = stream();
  var mux = new Mux(output);

  var pipedData = [1, 2, 3, 4, 5];
  var unpipedData = [6, 7, 8, 9];

  mux.pipeFrom(input);

  schedule(function () {
    pipedData.forEach(input.write.bind(input));
    mux.unpipeFrom(input);

    schedule(function () {
      unpipedData.forEach(input.write.bind(input));
      input.end();
      schedule(function () {
        // exhaust so that 'end' fires
        var v;
        while (v = input.read());
      });
    });
  });

  input.on('end', function () {
    output.end();
  });

  readAllObjects(output, function (vals) {
    try {
      assert.deepEqual(pipedData, vals);
      done();
    } catch (e) {
      done(e);
    }
  });
});

it('roundrobin', function (done) {
  var input1 = stream();
  var input2 = stream();
  var output = stream();
  var mux = new Mux(output);

  mux.pipeFrom(input1);
  mux.pipeFrom(input2);

  var endLatch = latch(2, function () {
    output.end();
  });
  input1.on('end', endLatch);
  input2.on('end', endLatch);

  var ones = [1, 1, 1, 1, 1];
  ones.forEach(function (v) {
    input1.write(v);
  });
  input1.end();

  var twos = [2, 2, 2, 2, 2];
  twos.forEach(function (v) {
    input2.write(v);
  });
  input2.end();

  readAllObjects(output, function (vs) {
    assert.deepEqual([1, 2, 1, 2, 1, 2, 1, 2, 1, 2], vs);
    done();
  });

});