node-x11/test/errors.js

var x11 = require('../lib');
var should = require('should');
var assert = require('assert');

describe('Client', function() {

  var display;
  before(function(done) {
      var client = x11.createClient({ debug: false }, function(err, dpy) {
          should.not.exist(err);
          display = dpy;
          done();
      });
  });

  it('should emit error which is instance of Error with sequence number corresponding to source request', function(done) {
    var times = 0;
    display.client.CreateWindow(); // should emit error
    var seq = display.client.seq_num;
    display.client.on('error', function(err) {
      switch (++ times) {
          case 11:
              display.client.removeAllListeners('error');
              done(1);
          break;
          default:
            assert.equal(err.constructor, Error);
            assert.equal(seq, err.seq);
            display.client.CreateWindow(); // should emit error
            seq = display.client.seq_num;
      }
    });
});
  });