stream-fail-solution.js

'use strict';
var through2 = require('through2');
var should = require('should');
require('mocha');

var failStream = function() {
  return through2.obj(function(chunk, encoding, callback) {
    this.push({})
    this.emit('error', new Error('failStream has failed'));
    callback()
  })
}

describe('catch stream errors', function() {
  it('should throw an error', function(done) {
    var stream = failStream();


    var onerror = function(err) {
      should.exist(err);
      err.toString().should.equal('Error: failStream has failed');
      this.removeListener('finish', onfinish);
      done();
    };

    var onfinish = function() {
      done(new Error('Expected stream to throw an error.'));
    };

    stream.on('error', onerror)
    stream.on('finish', onfinish);

    stream.write();
    stream.end();
  })
})

stream-fail-test-hack.js

'use strict';
var through2 = require('through2');
var should = require('should');
require('mocha');

var failStream = function() {
  return through2.obj(function(chunk, encoding, callback) {
    this.push({})
    this.emit('error', new Error('failStream has failed'));
    callback()
  })
}

describe('catch stream errors', function() {
  it('should throw an error', function(done) {
    var stream = failStream();
    var errored = false;

    stream.on('error', function(err) {
      should.exist(err);
      errored = true;
      err.toString().should.equal('Error: failStream has failed');
      done();
    })

    stream.on('finish', function() {
      if (!errored) {
        done(new Error('Error suppressed'));
      }
    });

    stream.write();
    stream.end();
  })
})

stream-fail-test.js

'use strict';
var through2 = require('through2');
var should = require('should');
require('mocha');

var failStream = function() {
  return through2.obj(function(chunk, encoding, callback) {
    this.push({})
    this.emit('error', new Error('failStream has failed'));
    callback()
  })
}

describe('catch stream errors', function() {
  it('should throw an error', function(done) {
    var stream = failStream();

    stream.on('error', function(err) {
      should.exist(err);
      err.toString().should.equal('Error: failStream has failed');
      done();
    })

    stream.on('finish', function() {
      done(new Error('Why does this still run?'));
    });

    stream.write();
    stream.end();
  })
})