XP in Anger

GUIDs, Primary Keys, and The Entity Framework

2011-12-31T00:39:00.000-05:00

I spent the evening learning about ASP.Net MVC 3 and thought I would share this bit of information with you. By default the entity framework uses integers for entity identifiers. After years of battling with scaleability issues, company mergers, and database consolidation projects I have come to prefer using GUIDs over integers or longs for tuple identity. The first thing I tried to do was change the POCO's datatype to GUID. However, the default value was being set to 16 zeros!

After a bit of STFW, I found this article that came up with a work around generating the Guid inside of the model. Then I found a MS support ticket where you could set StoreGeneratedPattern in some ridiculous xml configuration file. Thankfully I learned that EF also supports the use of attributes via System.ComponentModel.DataAnnotations:

[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]

public Guid ID { get; set; }

Equality Operators of Complex POCOs

2011-11-12T13:30:00.002-05:00

Usually I just hit "Alt+Insert" and ReSharper generates these methods correctly, but when your POCOs are composed of collections you will run into this little inconsistency. None of the .Net collections override the Equality operators, that means you will not be able to use your object as a Hash Key.

System.Linq.Enumerable comes to the rescue with SequenceEqual and ~~Sum!~~

Use it in the Equals method like so:
bool equal = other._fields.SequenceEqual(_fields);
...

GetHashCode looks something like:
~~int hashCode = _fields.Sum(field => field.GetHashCode());~~
...

Have fun!

Update: Nov 21, 2011
Turns out using Sum is a mistake! There is a high probability that the sum of the hash codes in the collection will exceed int.MAX_VALUE, which will in turn raise an OverflowException! I quick search using my favorite engine lead me to this article where the author provides a few solutions to the problem. I favored using the XOR to compute the composite hash code. The new implementation uses the Aggregate function and looks something like:
int hashCode = _fields.Aggregate(0, (total, field) => total ^ field.GetHashCode());

Web forms and null values

2011-07-08T23:38:00.001-04:00

Say you are building a javascript intensive application using jQuery and you wanted to send a literal null value to a server. You may start with the default behavior using the jQuery.ajax function:

var data = {  some_value: null };
jQuery.ajax({
           url: url,
           type: "PUT",
           data: data
});

However you discover that the default content type is application/x-www-form-urlencoded, which means that jQuery will serialize the data it will send in the message body. I was surprised to see that jQuery sets literal values such as "null" to a parameter value, e.g. data[some_value]=null, because the W3C recommendation, you'll realize that the specification states that browsers should omit null values altogether. This leads to having most web applications frameworks like Rails receive a string value instead of an absence of value.

Oh no! Does that mean there is no way to set the value to null? One option is to use JSON as the requests mime/content/media type:

jQuery.ajax({
     url: url,
     contentType: "application/json",
     type: "PUT",
     data: JSON.stringify(data),
     processData: false 
});

The server web framework will now interpret the JSON correctly and you get what you need. NULLS!

BDD, how I wish you did not exist.

2011-07-07T23:46:00.000-04:00

I read a blog post that got me all bent out of shape and I decided to replicate my reply on the blog.

"Shipping software is the goal, and the practices are a means to an end. The focus on shipping is no excuse for cutting corners, but perfect adherence to the practices is no excuse for not shipping." (Kent Beck:http://www.threeriversinstitute.org/JustShip.html)

This conundrum of whether or not "high ceremony development" is an valuable agile practice at start ups is interesting. I was not present at RejectConf 2011 but I will infer what Obie's comments were from that blog post you are referring to. As I understood it Obie was saying that using BDD tools like Cucumber or FitNess are a waste of time if they add little insight into the business domain. Let's explore this idea a little, what value does a business get out of a Cucumber Suite if your entire business domain is as simple as the Rails Blog Post Demo Crud App? What about the other extreme, what if they are still experimenting with new ideas and are actually creating a new domain? Most startups are coming up with ideas that they haven't really flushed out yet and still have to test the market and the Lean Startup community can tell you that there are better ways of obtaining that information without having to write "BDD" suites.

Personally I feel that BDD has caused a great deal of confusion and cargo cult culture in the software community. Dan North made a conscious decision to rebrand test driven development to behavior (or as the Brits spell it behaviour) driven development in order to make it more amenable to his teaching curriculum. In his own words:

"I had a problem. While using and teaching agile practices like test-driven development (TDD) on projects in different environments, I kept coming across the same confusion and misunderstandings. Programmers wanted to know where to start, what to test and what not to test, how much to test in one go, what to call their tests, and how to understand why a test fails. The deeper I got into TDD, the more I felt that my own journey had been less of a wax-on, wax-off process of gradual mastery than a series of blind alleys. I remember thinking “If only someone had told me that!” far more often than I thought “Wow, a door has opened.” I decided it must be possible to present TDD in a way that gets straight to the good stuff and avoids all the pitfalls. My response is behaviour-driven development (BDD). It has evolved out of established agile practices and is designed to make them more accessible and effective for teams new to agile software delivery." (Dan North:http://dannorth.net/introducing-bdd/)

Then BDD became a matter of pride:

"At the end of 2003, I decided it was time to put my money – or at least my time – where my mouth was. I started writing a replacement for JUnit called JBehave, which removed any reference to testing and replaced it with a vocabulary built around verifying behaviour. I did this to see how such a framework would evolve if I adhered strictly to my new behaviour-driven mantras. I also thought it would be a valuable teaching tool for introducing TDD and BDD without the distractions of the test-based vocabulary." (Dan North:http://dannorth.net/introducing-bdd/)

The original problem that Dan was trying to solve was that he felt like there was too much of a blank canvas and that there was too much of a focus on "testing". He wanted to give people a template to make it "easier" to get started with "testing" but now it has evolved into something different. "Over time, BDD has grown to encompass the wider picture of agile analysis and automated acceptance testing." (Dan North:http://dannorth.net/introducing-bdd/)

That is one of the things that I dislike about BDD tools and the cargo cult culture around them. To assert that these tools are the catalyst for a collaborative relationships between developers and their customers/product owners is absurd. There is NO guarantee these tools help developers gain deeper insight into a business domain. Thats what practices like planning, sitting together, ubiquitous language, whole team, user stories, customer examples, demos, and frequent releases try to address. The only tools that I know of to help with gaining insight are hard to automate, they are communication and feedback.

Why I Hate My Mac...

2011-06-26T23:01:00.001-04:00

I've had my MacBook for a few years now and I keep running into the same problem:

ariel@bloodchoke$ sudo strace -p 1144
sudo: strace: command not found
ariel@bloodchoke$ sudo /usr/sbin/strace -p 1144
sudo: /usr/sbin/strace: command not found
ariel@bloodchoke$ brew install strace
Error: No available formula for strace

UPDATE: I no longer hate my Mac, I am just frustrated with it. Thanks to Jim Nicholson for pointing out that FreeBSD offers a similar utility called truss. Brendan Gregg created a version of truss for the Mac that is built on dtrace.
Running it on the EventMachine tutorial "echo server", this is what I say...

ariel@bloodchoke$ sudo dtruss -f -p 200 
......
200/0x446:  select(0x7, 0x7FFF5FBFD6E4, 0x7FFF5FBFD764, 0x7FFF5FBFD7E4, 0x7FFF5FBFD868)   = 1 0
  200/0x446:  read(0x6, "afdnasklfasnm;fdas\n\0", 0x4000)   = 19 0
dtrace: error on enabled probe ID 1770 (ID 18322: syscall::read:return): out of scratch space in action #13 at DIF offset 44
  200/0x446:  sigprocmask(0x1, 0x0, 0x7FFF5FBFD600)   = 0x0 0
  200/0x446:  sigaltstack(0x0, 0x7FFF5FBFD5F0, 0x0)   = 0 0
  200/0x446:  select(0x7, 0x7FFF5FBFD6E4, 0x7FFF5FBFD764, 0x7FFF5FBFD7E4, 0x7FFF5FBFD868)   = 1 0
  200/0x446:  writev(0x6, 0x7FFF5FBFD580, 0x1)   = 19 0
  200/0x446:  sigprocmask(0x1, 0x0, 0x7FFF5FBFD600)   = 0x0 0
  200/0x446:  sigaltstack(0x0, 0x7FFF5FBFD5F0, 0x0)   = 0 0

There is no output file switch and there does not seem to be a way to increase system select function calls. The other thing I cannot seem to understand is why the file descriptor is nota simple integer. Using hex sucks.

Yeah, but too much X is dangerous

2011-02-15T00:30:00.001-05:00

Why is it that every time I hear someone say, "X is pretty good and very useful", there is always some Debbie Downer who feels the burden of reminding you; "Yeah, but too much X is dangerous".

Here is a conversation that went down between a polyglot programmer (PP) with a variety of experience and Debbie Downer (DD)

PP: It's really easy to redefine methods in Ruby in any context. In Java you have to write lots of extra code to deal with the problem of static methods or singletons in third party libraries, etc...

DD: Yeah, but dynamic methods are dangerous.

PP: It could be a problem, but in practice it never is. This amazing ability to override the existing behavior has been used in statically typed languages for years now and WE DON'T CARE AND IT'S NOT A PROBLEM! Here are some examples; [N]Hibernate decorates concrete PO*Os at runtime with proxies that afford developers the ability to lazily load relationships and track changes in a unit of work. That's what makes it so easy to use and how it knows how to optimize insert and update statements; and Spring uses proxies for @Transactional classes so that one isn't burdened with writing the same boiler plate DB transaction management code over and over.

DD: Those are examples of popular 3rd party libraries with well defined APIs, I am talking about code that people are working on at my company. That's when overusing dynamically typed languages is dangerous.

PP: Java and C# are not immune to problems because concrete implementations of interfaces could be deferred until runtime and anyone could simply give you a different implementation than you expected, but again that DOESN'T MATTER because what we are trying to achieve here is good old fashioned encapsulation and loose coupling. You shouldn't have to worry about the implementation of an interface that someone else is asking you to interact with.

DD: Yeah, but too much encapsulation is dangerous.

That's about the time that I walk away to get coffee.

Best Practices and Patterns, Aren't just for SmallTalk

2011-02-13T13:43:00.001-05:00

Here is a lightning talk I gave at Cyrus Innovation about the influence SmallTalk Best Practices and Patterns on my personal coding style.

Best Practices and Patterns, Aren't just for SmallTalk from Ariel Valentin on Vimeo.

Rails resource helper methods and the mistakes I make using them

2011-02-07T22:23:00.001-05:00

Here is something that always trips me up when I am working with Rails resources and I do not for the life of me know why:


ariel@bloodchoke demo$ rails console
Loading development environment (Rails 3.0.3)
ree-1.8.7-2010.02 > w = Widget.create!(:name => 'foo')
 => # 
ree-1.8.7-2010.02 > app.widgets_path(w)
 => "/widgets.1"
ree-1.8.7-2010.02 > app.widget_path(w)
 => "/widgets/1"

Why doesn't Rails raise an exception when I try to do this?

"Stateful" Web Applications

2010-07-09T21:05:00.002-04:00

There's a dumb title, "Stateful Web Applications". One attribute that I love about the web is that it is stateless, that means that you can actually use the web to write applications that could scale.
Programmers who really did not understand the web spent all of their time adding artificial "statefulness" in the form of "session stores". Instead of using the power of the web we started creating "applications" that simply used http as a transport for our evil doing. Then came the RESTafarians who lead the charge trying to teach others of the virtues and power of the web.
Now I find myself in the trenches trying to lead others to the promise land! Then I run into little nuggets like the WebSockets API.

A WebSocket object with an open connection must not be garbage collected if there are any event listeners registered for message events. http://dev.w3.org/html5/websockets/#garbage-collection

I can see the future! Millions developers out there chomping at the bit, waiting to write a bunch of crappy socket code in JavaScript that they could not write in C. Can you see it? The thousands of failed projects in our future that tried to use WebSocket connection pooling frameworks to help deal with the fact that when under heavy load the server had too many file descriptors open, which brought the application to its knees. I guess I better start learning more about this technology so that someone can pay me to re-write it using a stateless technology. Good thing we already have the web.

Bad Pairs

2010-07-04T12:23:00.000-04:00

Like most people, the first time I heard about pair programming I thought it was a dumb idea. I would have never intentionally paired with anyone, however my project manager pointed out that we were pairing all of the time and did not realize it. Whenever we ran into production problems or one of the programmers on our team was stuck, we would sit together and solve the problem... in pairs.

Nowadays I intentionally pair all of the time and I can say with confidence that it has made me into a better programmer, communicator, and team mate but not all of my experiences have not been pleasurable. I have found that pairing, like many XP practices, is easy to get wrong. Project teams misunderstand and abused this practice in terrible ways.

Inspired by my colleagues @moss and @lgdean who put together a presentation on pairing, I decided it was time to start compiling a list of "pairing smells" that I have experienced over the years:

Pair Stenographer - A driver who has no opinion on the subject. The navigator dictates code while the driver types. The crazy thing is that there are companies out there actively searching to fill this role!

"Pair Programmer is an apprenticeship position whose primary responsibility will be to support one of the company's founders - whom will call the Senior Programmer for this description - in the design and implementation of software products. The Senior Programmer will dictate code in python, C++, or other languages to the Pair Programmer." http://newyork.craigslist.org/mnh/sof/1645696541.htm

If the driver is dictating code, tell them to drive and stop being a jerk.

"We're Lost" - This is when the navigator does not know what is going on or how we got here. As the navigator you should always know where the driver is taking you. If you do not know where you are ask the driver to "pull over" so that you can figure out what the current task is and review the changes in your current change set. Then produce a "map" of where you are headed so that you do not get lost again.

"I don't need directions" - The driver wants to change things ignoring any direction from the navigator. This usually happens because the driver does not respect the navigators programming skill. In this case the best thing for the navigator to do is pull the driver aside and give them direct constructive feedback. Diana Larsen and Ester Derby offer an excellent course where the participants are taught various techniques for providing others with feedback.

Pair Copy Editor - "You misspelled that... You forgot a semi-colon...". Navigators, please be patient and let the IDE, compiler, or test tell the driver what is wrong. The driver is not going to you both killed if they forgot a semi-colon.

e-mailing, texting, and talking on the phone - It's rude. Excuse yourself and go somewhere else.

Watch me look this up - At times innocuous, but pair researching can be a waist if you're both doing it using one workstation. Split up and perform the search simultaneously. When one of you finds something let the other know.

"What if I want to get a sandwich?" - Not everyone is on the same schedule. If you are hungry or have to take a bio break, do not feel compelled to stay at the workstation. It's OK if someone solos for a while.

"Want to pair in my (cube | office)?" - I cannot tell you the number of times I have declined these invitations. The guest is always at a disadvantage. Level the playing field by either setting up a shared workstation or use remote pairing and share desktops.

Pairing as training tool - I often hear people who advocate pair programming say that it is a great way to train new hires. In practice it is a not effective. Bad pairing is not a substitute for good training. When you hire people train them, otherwise your team may find them to be a burden and it has a poor effect on morale.

That's it for my first list. What "pairing smells" have you caught a whiff of?

Tap, tap, tap

2010-04-13T00:55:00.000-04:00

I attended a seminar with master Rigan Machado where he shared the history behind Brazilian Jiu Jitsu. With every technique he explained the person who introduced it and the event where they dominated opponents all the way to the championship. Unlike other martial arts who have also been around for centuries, BJJ continues to evolve due to active competitors that introduce new techniques and counters.
A few months later I had the pleasure of attending a seminar lead by Ryron Gracie who focused on facing our fear while training. He said "if you are afraid to get tapped when you spar, then you will never get better". He said for most people tapping, or surrendering to your opponent, is a sign of weakness because they are afraid that if others see you tap that you aren't any good at grappling.
As my Shihan Johnny tells us during every class, tapping just means you got caught and you will get caught hundreds of times, its all a learning process
Professor Gracie encouraged us to take risks and intentionally make "mistakes":

"...when you roll allow your opponent you in a triangle and practice escaping. The more you allow yourself to get caught, the more you will understand what it takes to get yourself out of trouble."

He told us that one should experiment a little in those positions; shift ones weight around; grab onto something; move ones hips slightly; and that will eventually one will learn to become comfortable and I guarantee you that you will be the best escape artist. Do not be afraid to tap, nobody really cares! No one will make fun of you or think your are terrible at this!

The trouble with self-organization

2010-04-13T00:50:00.000-04:00

A common anti-pattern of self-organizaing teams is the lack of a "capable" leader. Often people end up in leadership positions and they are not the "right person" for the job. What is worse is that we do not provide them with adequate tools or a support system to help them succeed. In my opinion good leaders are:

Knowledgeable - How well does this person 'know' your flavor of agile?
Empowered - Can actually make a difference? Do they have the authority to remove impediments?
Trustworthy - Does the technical team and the business believe in what this person has to say?

What about your team? Really? Wow you guys have a good team! That is pretty rare because...

Research has found that 97% of people are followers and only 3% are good leaders. If this is true it means that the contact person role is the responsibility of the wrong person 97% of the time. This also proved to be the fact. The self governed teams had become very reactive and ineffective, so now this organization faces this fact and reinstitute the positions of front line leaders. http://www.idcon.com/article-good-to-great.htm

I consider myself a three-percenter, ninety-seven percent of the time. ;)

BDD is not about tools

2010-04-13T00:28:00.002-04:00

My team had to integrate with a third party tool whose client library was written in javascript. In order to prevent sprinkling dependency dust all over our code base, we isolated our integration point in a gateway object. After a little research a few members on our team decided that they wanted to test drive the code using Blue-Ridge, which includes ScrewUnit. They felt that this library was very comprehensive and pretty stable. However, when it came time to write some tests, I was really not looking forward to introducing this tool into our codebase.

Screw.Unit is a Behavior-Driven Testing Framework for Javascript. It features nested describes. Its goals are to provide: a DSL for elegant, readable, organized specs; an interactive runner that can execute focused specs and describes; and brief, extensible source-code.

As I understand it, BDD is TDD that is well factored and uses an expressive vocabulary. Dan North started changing the way he thought about writing unit tests so that they were readable and make it easier to teach others unit testing.

I also thought it [JBehave] would be a valuable teaching tool for introducing TDD and BDD without the distractions of the test-based vocabulary.... Chris and I realized we were trying to define a ubiquitous language for the analysis process itself! http://blog.dannorth.net/introducing-bdd/

In my opinion these tools don't do anything special, they simply attempt to provide a template for developers to write structured unit tests. I personally also find the syntactic sugar, a.k.a DSL, of most of these frameworks to be confusing and inconsistent, which runs contrary to what Dan was trying to do with JBehave:

#xUnit
#-------------------
def test_new_accounts_should_have_an_initial_balance_of_zero
  account = create_new_account
  assert_has_zero_balance account
end




#RSpec
#-------------------describe "A new account" do  include AccountExampleHelperMethods  before do    account = Account.new  end  it "should have a balance of $0" do    helper_method    @account.balance.should eql(Money.new(0, :dollars))  endend

Is Ruby's Test::Unit::TestCase inferior to RSpec? Was the RSpec test somehow clearer and more expressive than the xUnit version? I claim that these frameworks do not magically lead you to a utopia of ubiquity and expressive code. Writing good, clean, valuable code is a skill.

Templates are good but great code is better...

David A. Black joins our team!

2009-11-16T22:10:00.003-05:00

A few weeks ago Joe and I had lunch with DABlack. A few weeks later he joined our team...

Can't wait until our first code review!

http://dablog.rubypal.com/2009/11/13/starting-a-new-job-in-december

Awful interview

2009-10-25T00:48:00.001-04:00

Dave Newton author of Apache Struts 2 Web app dev sent me a link to possibly the worst job interview I have ever had the *pleasure* of hearing. It is not for the faint hearted:

http://buckybits.blogspot.com/2009/06/best-jee-interview-ever.html

_why is not dead. He's frozen.

2009-08-21T20:03:00.005-04:00

The original Poignant-guide...
http://mislav.uniqpath.com/poignant-guide/

PDF format
http://programminggoody.com/why/whys-poignant-guide-to-ruby.pdf

GIT mirror
http://github.com/whymirror

Twitter Comments
http://favstar.fm/users/_why

ART && CODE Symposium: Hackety Hack, why the lucky stiff
http://www.vimeo.com/5047563

GWT Talk at Agile 2009

2009-08-13T22:05:00.002-04:00

My colleagues Daniel Wellman and Paul Infield-Harm will be presenting at Agile 2009. I recommend that you go!
http://blog.danielwellman.com/2009/08/gwt-presentation-at-agile-2009-conference.html

Steve Freeman and Nat Pryce book

2009-08-12T22:16:00.002-04:00

I cannot wait to get this book in my hands!

Here it is! http://www.mockobjects.com/2009/08/book-worst-is-over.html

Testing File Uploads in Rails

2009-06-29T22:50:00.003-04:00

I was frustrated today trying to figure out why the HTTP functions in Integration::Session were converting my UploadStringIO class parameters to String instances using 'inspect'. Turns out for these specific Rails 2.1.2 performance tests you have to use a special class named ActionController::TestUploadFile. Here is the sample documentation:


 # Essentially generates a modified Tempfile object similar to the object
 # you'd get from the standard library CGI module in a multipart
 # request. This means you can use an ActionController::TestUploadedFile
 # object in the params of a test request in order to simulate
 # a file upload.
 #
 # Usage example, within a functional test:
 #   post :change_avatar, :avatar => ActionController::TestUploadedFile.new(Test::Unit::TestCase.fixture_path + '/files/spongebob.png', 'image/png')
 #
 # Pass a true third parameter to ensure the uploaded file is opened in binary mode (only required for Windows):
 #   post :change_avatar, :avatar => ActionController::TestUploadedFile.new(Test::Unit::TestCase.fixture_path + '/files/spongebob.png', 'image/png', :binary)

Migration Helpers To Add Foreign Keys etc...

2009-06-18T15:12:00.003-04:00

Rails plugin for adding foreign key constraints in a simple way:
http://github.com/patientslikeme/migration_helpers/tree/master


add_foreign_key 'address', 'user_id','users'

They also have a few simplified utility methods:


update_row 'books', :set => { :price => 4.99 }, :update_all => true
delete_row 'books', :author => 'Tolkien'

Enjoy.

This code sucks

2009-06-12T21:37:00.001-04:00

Nat Pryce wrote an interesting article where he comments on "Complaining about Other Peoples Code". Pay attention to what your team members say while reviewing legacy code. Are they passing judgment on the aesthetics of the code or are they actually asserting that the author is a bad person?

ruby-prof, script/performance, and vendor/gems

2009-06-10T20:55:00.005-04:00

It seems I keep having all of this fun running into issues working with Rails 2. My most recent challenge was unpacking ruby-prof as part of a Rails 2.1.2 application. Over the past few months I have spent some time getting our project to the point that we were able to unpack our required gems. Everything was working great, until I tried to using ActionController::RequestProfiler a.k.a. script/performance/request to profile a controller action. However when I tried to use it our application complained that: `gem install ruby-prof` to use the profiler
Huh? I thought I unpacked the gem in the vendor directory? A quick directory list revealed that it was there: vendor/gems/ruby-prof-0.7.3
What could be wrong? I started to trace the request script to find this little gem call in the Rails source code:

     # File actionpack/lib/action_controller/request_profiler.rb, line 146
146:       def load_ruby_prof
147:         begin
148:           gem 'ruby-prof', '>= 0.6.1'
149:           require 'ruby-prof'
150:           if mode = options[:measure]
151:             RubyProf.measure_mode = RubyProf.const_get(mode.upcase)
152:           end
153:         rescue LoadError
154:           abort '`gem install ruby-prof` to use the profiler'
155:         end
156:       end

Really? Another Evil monkey patch in my source code:

     # File /lib/core_ext/action_controller/request_profiler.rb
  def load_ruby_prof
    begin
      require 'ruby-prof'
      if mode = options[:measure]
        RubyProf.measure_mode = RubyProf.const_get(mode.upcase)
          end
    rescue LoadError
      abort '`gem install ruby-prof` to use the profiler'
    end
  end

#config/environment.rb

 Rails::Initializer.run do |config|
   config.load_paths += Dir["#{RAILS_ROOT}/vendor/gems/**"].map do |dir|
     File.directory?(lib = "#{dir}/lib") ? lib : dir
   end
 end

 # Add pagination requirement
 require "#{RAILS_ROOT}/lib/core_ext/action_controller/request_profiler"

Daniel Wellman on "What to Expect When You're Automating Testing: Test-last Tips from an Agile Expert"

2009-05-19T22:17:00.002-04:00

My colleague and good friend Daniel Wellman has written another stellar article based on his personal coaching experience getting teams started on testing:
http://blog.danielwellman.com/2009/05/testing-tips-article-in-may-2008-better-software-magazine.html

Uncle Bob- What killed Smalltalk Could Kill Ruby Too

2009-05-08T21:26:00.001-04:00

Ruby Concordion on Rails - Getting Started

2009-04-16T21:11:00.004-04:00

UPDATE: The Ruby Concordion Project is pretty much inactive. This blog post is here for my own ego.

There aren't many tutorials out there about Ruby's version of Concordion so I figured that I would help you get started. In this post, I will give you some guidance on how to get started working with Rails 2.0+. The artifacts that concordion requires are:

Directories for your specifications
Directories for your instrumentation code, a.k.a. fixtures
Directories to output your test results
An easy way to include concordion functionality into your test suite
Provide Rake tasks to run with your build

Create a directory to store your specifications:
$APP_ROOT/test/specs

Create a directory to store your instrumentation code:
$APP_ROOT/test/fixtures

Add a $APP_ROOT/test/fixtures/concordion_test_helper.rb that will make it easy to use Concordion:
==============================================================


#I guess you don't really need this line
ENV["RAILS_ENV"] = "test"

#This adds your specification directory to the Ruby load path
$:.unshift File.join(File.dirname(__FILE__),'..','specs')

#Lazily assign the output directory that concordion will write to
ENV['RCOR_OUTPUT_DIR'] ||= File.join(File.expand_path(File.dirname( __FILE__)),'..','spec-output')

#Load the existing Rails test helper
require File.join(File.dirname(__FILE__),"..","..","test_helper")

#The Concordion main module
require 'concordion/test_methods'

#Decorates all classes that inherit from TestCase class with concordion functionality
class Test::Unit::TestCase

def self.inherited(child)
child.send(:include, Concordion::TestMethods)
end
end

===============================================================
Create a Rake task to run your fixtures as part of your application code:
$APP_ROOT/lib/tasks/concordion.rake
===============================================================

require 'rake/clean'

#Set the directory where all of the test results will go
ENV['RCOR_OUTPUT_DIR'] ||= File.join 'test','concordion','spec-output'

#Task will create the output directory on demand
directory ENV['RCOR_OUTPUT_DIR']

#Add the output directory to the clean task
CLEAN.include ENV['RCOR_OUTPUT_DIR']

namespace :test do
namespace :concordion do
desc "Prepares the environment for running tests"
task :prepare => ['clean','db:test:prepare', ENV['RCOR_OUTPUT_DIR']]
end
end

Rake::TestTask.new('test:concordion' => 'test:concordion:prepare') do |t|
t.libs << "test"
t.libs << Dir[File.join('test','concordion','specs'),File.join('test','concordion','specs','**','*')].select{|item| File.directory?(item)}
t.test_files = FileList[File.join('test','concordion','fixtures','**','*.rb')]
t.verbose = true
end

============================================================================Now you can create your specification here:$APP_ROOT/test/concordion/spec/order_state_rules.htmlThen the instrumentation:$APP_ROOT/test/concordion/fixtures/order_state_rules_test.rb============================================================================

require File.join(File.dirname(__FILE__),"concordion_test_helper")

class OrderStateRulesTest < Test::Unit::TestCase; end

That's pretty much it. In future posts I will go over how to write your first set of examples and some of the mistakes spec authors make while working with Concordion.

Ruby Concordion 0.9.9.9

2009-04-15T22:19:00.003-04:00

For those of you who have run who are getting cryptic errors while working with Concordion and Rails I have good news for you. Some of the bugs are fixed in version 0.9.9.9 out on RubyForge! As far as I know everything is working on with Ruby 1.8.6 and Rails 2.1 on both RHEL 4 x84_64 and Mac OS X i386.
If you have any trouble using this release feel free to post on our mailing list ruby-concordion@googlegroups.com and we will help you.
Happy Testing!

Rails vrs Ruby Error Messages

2009-04-09T00:46:00.001-04:00

Just discovered the following:
irb>nil.foo
NoMethodError: undefined method `foo' for nil:NilClass
from (irb):1

script/console>nil.foo
NoMethodError: You have a nil object when you didn't expect it!
The error occurred while evaluating nil.foo
from (irb):2

Holy Week Services Montclair, NJ

2009-04-08T19:25:00.001-04:00

Saint Peter Claver Church ¨ 56 Elmwood Ave., Montclair, NJ 07042 ¨ 973-783-4852

HOLY THURSDAY
April 9^th
7:00 PM – Solemn Mass of the Lord's Supper, Operation Rice Bowl Collection, followed by Adoration of the Holy Eucharist

GOOD FRIDAY
April 10^th
Solemn Liturgy of the Passion and Death of Jesus
6:30 PM – Stations of the Cross begins in church w/ neighborhood procession followed by the Solemn Liturgy of the Lord's Passion.

HOLY SATURDAY EASTER VIGIL
April 11^th
Blessing of Fire, Easter Candle & Water
7:30 PM – Solemn Easter Vigil Celebration

EASTER SUNDAY
April 12^th
The Ressurection of the Lord Jesus
9:00 AM – English Eucharist
11:00 AM – English Eucharist
12:45 PM – Creole Eucharist
6:00 PM – Spanish Eucharist

DIVINE MERCY SUNDAY
April 19^th
5:45 PM [Sat.] – English Eucharist
9:00 AM – English Eucharist
11:00 AM – English Eucharist
12:45 PM – Creole Eucharist
6:00 PM – Spanish Eucharist

SPIRIT OF EASTER MASS
Tuesday, April 21^st7PM

Ola Bini on Null Types

2009-03-16T14:16:00.001-04:00

His ability to articulate difficult concepts continues to impress me:
http://olabini.com/blog/2009/03/bottom-types-in-dynamic-languages/

Advanced Ruby Studio

2009-03-09T12:15:00.005-04:00

I recently attended Advanced Ruby Studio taught by Dave Thomas and Chad Fowler. It was hands down the best training experience I have ever had. I highly recommend that you attend!

The Phone Book Is Here!

2009-03-08T19:10:00.002-04:00

Finally Paul Infield-Harm has a blog! http://www.infield-harm.org/blog/

Ruby Concordion Moved

2009-03-06T23:26:00.001-05:00

Ben has moved hosting to Ruby Forge
http://rubyforge.org/projects/ruby-concordion/
Check it out!

ActionView::TestCase errors Rails 2.1.2

2009-03-01T12:41:00.001-05:00

I started to use the built in Rails test case extensions when we upgraded a few months ago, however every once and a while I run into something that causes me frustration to no end.

Our team wrote helper that would render a remote_function call as part of its contents:


require 'test_helper'
require 'action_view/test_case'

class ApplicationHelperTest <  < method =""> :get, :controller => 'main', :action=> 'open_item', :id => 1)
 end
end

Executing this test resulted in an odd error:


[root@new-host-2 qme]# ruby test/unit/application_helper_test.rb --name test_demonstrates_bug
Loaded suite test/unit/application_helper_test
Started
E
Finished in 0.516956 seconds.

1) Error:
test_demonstrates_bug(ApplicationHelperTest):
NoMethodError: undefined method `protect_against_forgery?' for #applicationhelpertest:0x2a97ff0d68
  /usr/lib64/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action_controller/test_process.rb:467:in `method_missing'
  /usr/lib64/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action_view/test_case.rb:55:in `method_missing'
  /usr/lib64/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action_view/helpers/prototype_helper.rb:1053:in `options_for_ajax'
  /usr/lib64/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action_view/helpers/prototype_helper.rb:443:in `remote_function'
  test/unit/application_helper_test.rb:17:in `test_demonstrates_bug'
  /usr/lib64/ruby/gems/1.8/gems/activesupport-2.1.2/lib/active_support/testing/setup_and_teardown.rb:67:in `__send__'
  /usr/lib64/ruby/gems/1.8/gems/activesupport-2.1.2/lib/active_support/testing/setup_and_teardown.rb:67:in `run'

1 tests, 0 assertions, 0 failures, 1 errors

I do not know what the root of this was, but I figured that my test did not care about protecting against forgery so I defined the method:


 def protect_against_forgery?
 end

Then I ran the test again, which resulted in a new error:


1) Error:
test_demonstrates_bug(ApplicationHelperTest):
NoMethodError: You have a nil object when you didn't expect it!
The error occurred while evaluating nil.url_for
   /usr/lib64/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action_view/helpers/url_helper.rb:71:in `send'
   /usr/lib64/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action_view/helpers/url_helper.rb:71:in `url_for'
   /usr/lib64/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action_view/helpers/prototype_helper.rb:461:in `remote_function'
   test/unit/application_helper_test.rb:20:in `test_demonstrates_bug'
   /usr/lib64/ruby/gems/1.8/gems/activesupport-2.1.2/lib/active_support/testing/setup_and_teardown.rb:67:in `__send__'
   /usr/lib64/ruby/gems/1.8/gems/activesupport-2.1.2/lib/active_support/testing/setup_and_teardown.rb:67:in `run'

1 tests, 0 assertions, 0 failures, 1 errors

Reading the source code it turns out that UrlHelper is trying to invoke @controller.url_for... really? I thought that it was initialized in the TestCase setup method? Turns out that it only creates a controller in the event a method is missing on in the TestCase...

 
     def method_missing(selector, *args)
       controller = TestController.new
       return controller.send!(selector, *args) if ActionController::Routing::Routes.named_routes.helpers.include?(selector)
       super
     end

I then initialized the controller as an instance member in setup() and things worked just fine.

 
    setup :setup_with_helper_class

    def setup_with_helper_class
      if helper_class && !self.class.ancestors.include?(helper_class)
        self.class.send(:include, helper_class)
      end
      @controller = TestController.new
    end

I am not sure if all of these crazy things I did were good or bad things, particularly if I have forever inhibited my ability to protect_from_forgery in my tests but I guess I can live with it until I can file a request for fix with the Rails team.
Hope this helps...

Agile 2009 Proposals

2009-03-01T11:02:00.002-05:00

I am really excited about possibly leading some presentations this year. I submitted a proposal for Agile 2009 to give a talk about Ruby Concordion and I would love some feedback:
http://agile2009.agilealliance.org/node/2543

Bruce Eckfelt will also be presenting and I will be the Ward to his Wayne. I also make the distinction because Jason Todd died at the hands of the Joker and I want to LIVE! You can follow his proposal here:
http://agile2009.agilealliance.org/node/150

Here is the full list of Cyrus submissions:

2543	Concordion - Testing in plain "English"	Ariel Valentin		12 hours 17 min ago
150	Let's Build a Boat: A Simulation of Just-In-Time Production	Bruce Eckfeldt	Ariel Valentin	16 hours 15 min ago

154	How to Say "No." (Without Destroying the Relationship)	Bruce Eckfeldt	6 weeks 2 days ago
152	All I Needed to Know About Agile I Learned From Deming	Bruce Eckfeldt	6 weeks 2 days ago
151	Target Cost Contracting: Part Deux	Bruce Eckfeldt	6 weeks 2 days ago

ID	Title	1st author	2nd author	Updated
134	Test-Driving AJAX applications with Google Web Toolkitnew	Daniel Wellman	Paul Infield-Harm	1 day 17 hours ago

ID	Title	1st author	2nd author	Updated
1130	How to manage the non-software part of your job with Lean and Scrum	Rex Madden		2 hours 17 minago
1128	Zendo and the Art of Debugging	Rex Madden		2 hours 49 minago

Ruby Concordion 0.9.8 - Now integrates with Rails!

2009-03-01T00:45:00.001-05:00

Just wanted to announce the latest version (0.9.8) of Concordion written in Ruby. There are quite a few updates that make it easy to integrate with other frameworks such as Rails who decorate Test::Unit::TestCase using inheritance.

Step one:
gem install concordion

Step two:
Enjoy! http://code.google.com/p/rcor/wiki/Tutorial

RCor now just plain ole Concordion

2009-02-17T19:13:00.000-05:00

Ben has renamed the project :) Check it out here

MySQL Default Strings

2009-02-16T21:47:00.001-05:00

Assess Your Agility...

2009-02-16T20:48:00.001-05:00

How agile are you?

http://jamesshore.com/Blog/abetterteam.html

Frustrated with change_column Rails 2.1.2

2009-02-16T16:21:00.007-05:00

My team tried upgrading from Rails 2.1.0 to 2.1.2 and ran into a few frustrating problems. When we first defined our tables in rails 1.2.6 we used "string" data types for certain columns:

create_table :widgets do |t|
  t.string :form_data, :default=>"" :null=>false
  t.timestamps
end

A few months went by and we decided to upgrade from 1.2.6 to 2.1.0 but it required us to change from strings to text fields. The migration script looked like this:
change_column(:widgets, :form_data, :text, :default=>"")
In Rails 2.1.2 the change_column function retained its nullability unless you explicitly requested it, however in 2.1.0 it would always redefine it to the defaul null => true. Tailing the logs confirmed this subtle difference:
2.1.0 => ALTER TABLE widgets CHANGE COLUMN form_data text DEFAULT '' NOT NULL
2.1.2 => ALTER TABLE widgets CHANGE COLUMN form_data text DEFAULT ''
We then had to create another migration so that we would be in sync with our production database:
change_column(:widgets, :form_data, :text, {:default=>"", :null => true })
Annoying but true.

Rails migration and the dreaded MyISAM-InnoDB MySql Error

2009-02-13T09:54:00.002-05:00

Our team found itself staring at ONE Linux workstation screen trying to fix the following problem:

-- execute("ALTER TABLE widgets ADD CONSTRAINT fk_widgets_gadgets FOREIGN KEY(gadget_id) REFERENCES gadgets(id)")
rake aborted!
Mysql::Error: Can't create table './foo_development/#sql-3779_341.frm' (errno: 150): ALTER TABLE widgets ADD CONSTRAINT fk_widgets_gadgets FOREIGN KEY(gadget_id) REFERENCES gadgets(id)

In my experience this error only means one thing, there are records in the table that violate the foreign key constraint. Finding the orphaned records should be easy right?

select * from widgets where gadget_id not in (select id from gadgets)
0 records found

The worst part about this problem is that it was only happening in only one of the developers sandbox databases as well as in our pre-production environments. It seemed as if it would be impossible to figure out what was happening. Our quest to destroy the ring was just beginning.
I took a look at the constraints table because we had added constraints to the widgets table before, why would this one be any different?

USE information_schema;
SELECT * FROM table_constraints WHERE table_schema = 'foo_development';

The results did not display anything out of the ordinary, the other constraints where there!!! At this point I was running out of ideas. We started to compare the tables in development from test when boom there it was: [gadgets TYPE=MyISAM and widgets TYPE=InnoDB]
SON OF A.... ALTER TABLE gadgets TYPE=InnoDB

REST and the Resource

2009-02-10T20:41:00.005-05:00

Something that often happens on applications that I've worked on is the need to access a resource in a particular context. For example, you have a application where students submit their homework assignments allowing teachers to grade them.

Using a resource oriented application, you may allow students to access their submitted assignments to make comments, view their grades, etc... using this URI:
/students/avalentin/assignments/

On the other hand a teacher would like to access a particular students assignments with a few more options, such as copy-editing or grading the submission. However making the resource available from the same URI as a student does not provide the context that the teacher is reviewing the item. In that case you may provide a URI that looks like this:
/teachers/cgjung/students/avalentin/assignments/

The great thing about this URI is that it gives you a context, "As a teacher I want to view a students assignments" vs "As a student I want to view the assignments I submitted for grading"

Now Rails makes it easy to accomplish this goal. First make students available as a resource with the following mapping:
map.resources :students

Next make that students assignments available as a nested resource:


map.resources :students do |students|
    students.resources :assignments
end

Now you can access a specific students assignments using this URI
/students/{student id}/assignments/{assignment id}

The teachers mapping looks more or less like this:


map.resources :teachers do |teachers|
  teachers.resources :students do |students|
    students.resources :assignments
  end
end

This access a specific students assignments using this URI
/teachers/{teachers id}/students/{student id}/assignments/{assignment id}

That's it really. Well not really. Those mappings actually result in non-human discernible URIs that look like this:
/teachers/9999/students/4353/assignments

Now maybe I'm over analyzing this but my preference would be to have resource identifiers that have a logical meaning that is not tied to some database identity...

Help Us Feed Others!

2009-02-02T19:06:00.002-05:00

Hello my fellow readers!

We really need your help to raise funds that support our many social programs that service homeless families in Montclair, NJ through Saint Peter Claver Church. Please Support Social Concerns through our Annual Mardi Gras Event.

All profits from the event go to one of St. Peter Claver’s most important goals, helping people in need. Providing help is especially critical during these tough economic times. Demand for services has increased sharply, particularly for the church’s food pantry. Supplies have dwindled quickly. The following are the programs you can help:

Our FOOD PANTRY is open five days a week and regularly feeds 60+ people in the community. The money you donate will help stock this pantry and provide some families with supermarket gift cards. You can also donate food or gift cards anytime throughout the year.

THANKSGIVING meals with all the trimmings are prepared for 75 + people each year.

EMERGENCY FINANCIAL AID is given to needy people in the community for things like prescription drugs, gas and electric bills and bus cards to get to work.

HELPING THE HOMELESS- Twice a year, the church opens its doors for a week to host HOMELESS families through the Interfaith Hospitality Network. The church helps feed these families, provides money for laundry service and makes their stay comfortable.

The COMMUNITY TUTORING PROGRAM is run by the Montclair Public Schools in the church’s technology lab. Educational books, PC-based software paper, pencils, flash cards, work books, or juice and snacks are always needed.

Each day, St. Peter Claver opens its doors and provides heat and electricity to a number of nonprofit groups, among them the NAACP Education Committee, NJ Peace Action and People’s Organization for Progress.

We hope that you will share in the church’s mission to help the less fortunate. The following are the many ways you can help raise money for social concerns and all profits go towards social concerns:

Purchase an ad in the Mardi Gras Program (all profits go towards social concerns):
- $200 Full Page Inside Cover
- $100 Full Page
- $50 Half Page
- $$25 Quarter Page
- $10 Sponsor
Donate a gift basket (or items to fill a gift basket) that will be raffled (all profits go towards social concerns)
Attend the Mardi Gras Party on Feb. 21 at Senorita’s Restaurant in Bloomfield $35 adt /$15 chd
Purchase Gift Basket Raffles tickets (at the Mardi Gras Party - Feb 21)
Purchase 50/50 tickets (available Feb 8 – Feb 21)

The form for your contribution towards helping the needy could be found here:

http://docs.google.com/View?docid=df26w9km_25gvst784c

Thank you for caring. As Mother Teresa said:

“If you can’t feed a hundred people, then feed just one.”

St. Peter Claver Church • 56 Elmwood Ave. • Montclair, NJ 07042

The Well-Grounded Rubyist

2009-01-29T13:15:00.004-05:00

David A. Black is wrapping up a new book that covers the features in Ruby 1.9
Here is a sample chapter http://www.infoq.com/news/2009/01/The-Well-Grounded-Rubyist

Follow him on twitter @david_a_black and his blog http://dablog.rubypal.com/

RCor 0.9.0 - Concordion in Ruby

2009-01-28T11:35:00.006-05:00

Rcor 0.9.0 has been released.

It fixes some CSS issues (which led to misleading reporting) as well as improved support for verifyRows, which models the behavior of FIT row fixtures.

See the wiki page on it, http://code.google.com/p/rcor/wiki/verifyRows, for details.

====================================

Just wanted to announce that RCor 0.8.7 was released yesterday!

Its got a few bug fixes in it as well as better error reporting.

Here is the link to download the latest version:
http://code.google.com/p/rcor/downloads/list

Thanks to Christopher Gardner and Ben Goodspeed for the changes!

You are welcome to ask questions on our google group or join in on the action!
http://groups.google.com/group/ruby-concordion

Testing is overrated - video

2009-01-27T12:59:00.003-05:00

This is a pretty good presentation for those of you out there trying to become better testers.

http://www.infoq.com/presentations/francl-testing-overrated

Speak

2009-01-26T20:46:00.001-05:00

I just disabled moderating comments as well as enabling anonymous users. I've always wondered what you think.

The Team

2009-01-25T22:29:00.000-05:00

Like many projects success or failure largely depends on your team. If you have good business people, good developers, good chemistry, good leadership, etc... chances are you will be successful. It does not matter if you are using a so called "Agile" practices or not. If the people on your team can't work together you are pretty much going to fail.

Kaizen Antipatterns or You suck at getting better

2009-01-25T12:07:00.000-05:00

I have noticed that people have a bad tendency of blaming Agile for them not being able to do their jobs right. Take Kaizen for example, most of the teams that tell me they are practicing it have no idea what they are doing. They think that Kaizen events are a waste of time because they sit around and bitch for a few hours rather than actually trying to come up with a strategy to get the job done right.
Here are a few smells I think you should watch out for when running such an event:

Mistaking Kaizen for Kaikaku (rapid, large, revolutionary change). In my experience, unless the project team has influence across the organization, these plans collapse under their own weight.
Tyring to fix too many things at once.
Not producing concrete measurable action items and assigning them to the team.
Conducting Kaizen events like a therapy session. During Kaizen events, there are opportunities to explore "unreasonable or excessive strain", which often effects team members on an emotional level. The goal of Kaizen is to eliminate the source of the "strain", not to "heal" the teams psychie.
Identifying a person or team member as the root cause of the problem.
Allowing subjective moderators to conduct the events.
Use Kaizen as a platform to push agendas instead of solve problems.
Kaizen events take place long after the problem is identified.
Not understanding Kaizen metaphors for Software Development.
"Not asking for the Check" - This is when the team does not follow up on the Kaizen action items.

How Ruby made me into a better Java... TDDer?

2009-01-25T12:01:00.000-05:00

While I was coaching a few teams last summer I realized that my perspective on testing Java applications changed because of Ruby. I used to be one of those people who would not to use databases when writing automated "unit" tests. I would then advise others to use test spies instead of the actual database dependent code. That works when you are working with code that interacts with a repository but what about when you test the repository itself? Well you all know how that ends up.
When I started to work with Ruby I started to apply the same mechanics that I used while working on Java projects, however I quickly discovered that my prejudice from working with other tools was an impediment to my success. Tests where fast and the tools where simple in spite of the fact that they dependend on external sources.
After working with Ruby, I returned to Java questioning my assumptions about testing. At first I started by writing component level tests that would execute the entire stack because I thought that Rails like functional tests would make sense in my Java world. The good thing that happened there was I discovered a rats nest of performance problems in our production code and it got my XP team thinking about how much we really ignored the P in Right BICEP. However, the tests were slow and after profiling them it was clear there was very little we could do to improve the performance. All of the resources in the tests were exhausted in bootsrapping, Spring contexts, Hibernate SessionFactory, etc...
Our team then went on to talk about what was going on. Turns out that the tests where telling us there was something wrong with the design, we just were not listening to them. What happened to "Tell, Don't Ask"? Why did my code suffer from so many smells?
Just around this time I discovered that Nat Pryce and Steve Freeman where writing their book on Growing OO Software Guided by Tests. Reading this helped me go through sort of an OO design revival and return to a tabula rasa.
I strongly believe that learning and working with Ruby has opened new doors for me both as a tester and designer. It has forced me to challenge what I thought was good code and now more than ever I realize how TDD is an art form that is difficult to master. It isn't some mechanical exercise that you can teach someone easily. It is a discipline that takes practice, time, and above all support from a good team.

I heart Ruby

2009-01-06T23:38:00.003-05:00

Here is another reason why I love Ruby:
?> module Sweatshirt
>> def self.included(klass)
>> klass.extend ClassMethods
>> end
>>
?> module ClassMethods
>> def read_aloud
>> "Now I have a machine gun"
>> end
>> end
>> def read_aloud
>> "ho, ho, ho"
>> end
>> end
=> nil
>>
?> class DieHard
>> include Sweatshirt
>> end
=> DieHard
>>
?> puts "#{DieHard.read_aloud} #{DieHard.new.read_aloud}"
Now I have a machine gun ho, ho, ho
=> nil

Class and class variables...

2008-12-27T12:18:00.004-05:00

When is a class variable a class variable? When it's not an instance variable I guess:
irb>>
>> class Foo
>> attr_reader :foo
?> @foo = "I exist in the class object" #class instance variable
>> @@foo = "I have no idea where I exist" #class variable
>>
?> def initialize(*args)
>> @foo = "I am an instance variable" #instance variable
>> end
>>
?> def self.read_foo
>> puts Foo.new.foo
>> puts @foo
>> puts @@foo
>> end
>> end
=> nil
>>
?> Foo.read_foo
I am an instance variable
I exist in the class object
I have no idea where I exist
=> nil
>>

Installing RCov on Mac OS X.5

2008-12-18T21:06:00.004-05:00

I tried installing rcov on my Mac OS 10.5.6

$>sudo gem install rcov
Password:
Building native extensions. This could take a while...
ERROR: Error installing rcov:
ERROR: Failed to build gem native extension.

/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb install rcov
can't find header files for ruby.

Gem files will remain installed in /Library/Ruby/Gems/1.8/gems/rcov-0.8.1.2.0 for inspection.
Results logged to /Library/Ruby/Gems/1.8/gems/rcov-0.8.1.2.0/ext/rcovrt/gem_make.out

Really? That sucks. I asked the interweb and I found this post:
http://www.macruby.org/trac/wiki/Troubleshooting
OK so I installed Xcode 3 from here: http://developer.apple.com/Tools/xcode/ and then installed mac ports from here: http://www.macports.org/

Everything worked after that! Awesome!

Corey Haines insights - Tools Vs. Technique

2008-12-12T17:39:00.001-05:00

Corey provides some awesome insights while on the road pair programming with great developers:
http://programmingtour.blogspot.com/2008/12/road-thoughts-tools-v-technique.html

What's missing from the manifesto?

2008-12-07T21:50:00.001-05:00

Brian Marick on "What the manifesto left out"

Courtesy of Michelle

2008-11-26T20:29:00.001-05:00

An SQL query goes into a bar, walks up to two tables and says, "Can I join you?"

REST Track at QCon

2008-11-24T19:45:00.002-05:00

I really wanted to go to this and after reading Jim Webber's posts on the REST track, I really regret having stayed home!

Rails config for concordion

2008-11-23T23:24:00.003-05:00

I am working with rcor, a ruby port of concordion, and I have run into a little setback working with Rails. RCor searches the $LOAD_PATH to find the html specifications, so I decided to add it to the standard config/test.rb. Here was the output:

new-host:rcor-spike ariel$ rake test
(in /Users/ariel/Documents/dev/bookstore)
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby -Ilib:test "/Users/ariel/.gem/ruby/1.8/gems/rake-0.8.3/lib/rake/rake_test_loader.rb" "test/unit/book_test.rb" "test/unit/hello_world_test.rb"
Loaded suite /Users/ariel/.gem/ruby/1.8/gems/rake-0.8.3/lib/rake/rake_test_loader
Started
...E
Finished in 0.073126 seconds.

1) Error:
test_spec(HelloWorldTest):
RuntimeError: Could not find hello_world.html on the system load path!
  /Users/ariel/.gem/ruby/1.8/gems/rcor-0.7.0/lib/concordion_reader.rb:15:in `find_on_load_path'
  /Users/ariel/.gem/ruby/1.8/gems/rcor-0.7.0/lib/concordion_reader.rb:4:in `read'
  /Users/ariel/.gem/ruby/1.8/gems/rcor-0.7.0/lib/concordion_parser.rb:22:in `parse'
  /Users/ariel/.gem/ruby/1.8/gems/rcor-0.7.0/lib/concordion_test_case.rb:69:in `parse_spec'
  /Users/ariel/.gem/ruby/1.8/gems/rcor-0.7.0/lib/concordion_test_case.rb:22:in `test_spec'
  /Users/ariel/.gem/ruby/1.8/gems/activesupport-2.1.1/lib/active_support/testing/setup_and_teardown.rb:67:in `__send__'
  /Users/ariel/.gem/ruby/1.8/gems/activesupport-2.1.1/lib/active_support/testing/setup_and_teardown.rb:67:in `run'

4 tests, 3 assertions, 0 failures, 1 errors

Really? Well it doesn't work. I had to add the following line to my config/environment.rb: config.load_paths += %W( #{RAILS_ROOT}/test/acceptance ) if ENV['RAILS_ENV'] == 'test'
WhyTF do I have to do this? Rather than STFW or RTFM I am blogging about it. Talk about open-closed jeez!!!

Non Functional Requirements as stories

2008-11-22T12:29:00.003-05:00

Mike Cohn has this to say:

These are requirements that are not about specific functionality (”As a user of a word processor, I want to insert a table into my document.”), but are rather about an attribute or characteristic of the system... “If it’s non-functional, why do I care about it?”... Each constraint we put on a system narrows the design choices a bit; calling these “constraints” rather than “non-functional requirements” helps us remember this... Trying to put a constraint into this template is a good exercise as it helps make sure you understand who wants what and why.

This post resonates with me because I firmly believe that any feature in your application must fulfill the needs of its users not its engineers. Doing so will encourage simplicity in your application development that way you avoid useless stories like, As an architect, I want for the system to be integrated using an ESB (so that my resume looks good and I can frustrate the developers who are forced to use it).

Rails periodically_call_remote issue

2008-11-18T23:37:00.005-05:00

Here is an interesting problem that I ran into today. A few guys where working on a feature that used a progress bar to give a user feedback on the status of a background task. In order to do this, they used the Rails prototype helper periodically_call_remote method however they noticed that multiple requests were being fired after an interval had passed. I wasn't sure what was happening so I started to read the source code and as of the time of the writing of this post periodically_call_remote creates a PeriodicExecuter but does not ever stop it. According to the Prototype website: "Once launched, a PeriodicalExecuter triggers indefinitely, until the page unloads (which browsers usually take as an opportunity to clear all intervals and timers) or the executer is manually stopped"
e.g. of stopping manually:

new PeriodicalExecuter(function(pe) {
                              if (!confirm('Want me to annoy you again later?'))
                              pe.stop();
                              }, 5);

Now what happens is that every time the application rendered the ajax call, it spawned a new executor, which ends up hanging around for a while. This would not be a problem if the browser "unloaded" itself every once and a while so here is some advice... if you need write a feature that requires rendering a periodically_call_remote multiple times then you are probably doing it wrong.

How the F**k????

2008-11-16T21:34:00.003-05:00

How did Luke get Lebron on his team!

Death to Agile - Rebuttal

2008-11-16T10:09:00.004-05:00

Uncle Bob posted a rebuttal to Shores post.

Some have implied that if all those scrum teams had adopted XP instead of scrum, they wouldn’t be having all the technical debt they are seeing. BALDERDASH!... Let me be more precise. ASININE, INANE, ABSURDITY. BALONEY. DINGOES KIDNEYS.

I do not think that Jim alluded to that at all but OK. I have been on too many teams that are composed of the wrong people, the wrong talent, the wrong leadership, in the wrong place, at the wrong time. The teams that gave birth to many of the agile practices where composed of all-stars! Think about the first XP team on the C3 project, wouldn't you be successful with these guys on your team: Beck, Fowler, Cunningham, Jefferies, Hendrickson?
If I read the next part correctly he believes its your job to do a good job...

But it is neither the purpose of scrum nor of CSMs to make engineers out of us, or to instill the disciplines of craftsmanship within us. That’s our job!... Oh, yeah, and stop blaming everything (and everybody) else for your own laziness.

As you can tell I agree with Uncle Bobs position on individual responsibility however the fact of the matter is perception is a reality.
The industry, like a mob, is not rational or scientific; it often blindly follows trends; it believes and accepts fallacies as truth; and it subscribes to leadership of the "strongest" of the group. From the mobs perspective, failing at agile (a.k.a Scrum) means failing at agile (Scrum, XP, Crystal, et al.). That's the a terrible reality and Jim is afraid that we are in trouble as a result.
As I stated in my earlier post I say f**k it. Just let people fail there is nothing wrong with that. Let them think that agile sucks because what they are practicing right now actually does.

Death to Agile

2008-11-15T22:56:00.003-05:00

In this blog post James Shore expresses a bit of concern about the bad reputation agile has gotten as a result of "malpractice". If I read it right, he feels that this reputation will lead to the baby being thrown out with the bathwater:

Whatever we do, we need to do it soon. Agile is failing all around us, and I'd hate for the failure of the fad to take down the truly useful ideas that we started with.

To tell you the truth I can't wait until "agile" dies. I am sick of it.

More on "Technical" User Stories

2008-11-11T21:23:00.007-05:00

Consider a project where you are replacing an antiquated system for the police department and you have a user story similar to "As the captain, I want to know about the crimes committed in our precinct so that I know where to assign officers and reduce crime". Now imagine that your project team is composed of individuals in very well defined roles such as UI designers, server side developers, DBAs, and sysadmins.
How would this team go about implementing this story? In my experience the system would be designed in layers with integration occuring after each team completed the work on their tier. Then there is the question of, what do we do about the "old system"? Some feel that disabling or perhaps integrating the antiquated system with the new feature in the "old system" should be part of the "definition of done" while others believe that it should be treated as a separate user story. Scott Ambler wrote an article on the subject where he describes the problem with creating user stories that focus on these "so-called" non-functional requirements:

All interesting requirements, but each one on their own provides very little value until you put them in the greater context of sending out marketing literature to a targeted group of customers. Until all of those user stories, and more, are implemented your system really doesn't provide true business value to your stakeholders, regardless of the fact that you have been producing potentially shippable software every iteration up to that point.

Now if you have not read my original rant on "technical" user stories, then I should probably let you know that I believe it is a bad idea. The simplest approach IMO is to pair down user stories into the smallest vertical slices possible and incrementally add support for more general features. Using my example above, we could reduce this story to a specific type of crime. Another way to reduce the scope from an entire city to a neighborhood. Do whatever it takes to make it small enough to get "production releasable software" in one iteration. Its not that hard.

RubyConf 2008 Day 3 - Code Review

2008-11-08T13:25:00.006-05:00

There is not much I can say about this. I actually felt a little uncomfortable because it was poking fun at some of my customers. Here are some of the problems they pointed out:

Leave no broken windows
Fixtures are brittle
Do not test "validate" using invalid data in your fixtures
Use VI as your editor
If you need default values for your Model, encode them in a class method
Use "comment out code" while writing characterization tests
hook methods ... check if it applies to you.. make sure you call super in another if you are implementing decoration using inheritance

RubyConf 2008 Day 3 - Advanced DSL's in Ruby

2008-11-08T10:29:00.007-05:00

Neal Ford gave this talk and I would say that this was one of the best presentations at this conference. For the most part Neil is talking about some of the patterns that Fowler has been working on in his book only using examples written in Ruby. Ford also introduces some patterns he has identified and a handful of interesting frameworks to help support writing both internal and external DSLs.

The Beginning
He started by discussing the fluent interfaces, which use method chaining to express logic in a "sentence". The challenge with using this style is how method chaining semantics requires "an explicit terminator ", but that causes a "the finishing problem" because it breaks the fluency in the language. In order to mitigate this problem he advised the audience to use a wrapper context and use nested methods to control completion: e.g. rules.add(Discount.new.based_on(foo)) instead of rules.add_discount_based_on(foo)

The Middle
Another thing to keep in mind is that we should control the context. In other words, alias methods so that it reads a little better: e.g. Instead of recepie.instance_eval { @ingredients } alias instance_eval to provide context recepie.consists_of{ @ingredients }
He goes on to discuss a few more ways to combat the finishing a.k.a. stopping problem. A common mistake he sees people make in Ruby is using method_missing as a factory to create types. This approach violates the open-closed principle so he advised the audience to use Mixins and builders instead of using method_missing.

Almost at the End
Some other interesting things he discussed where function sequences, bubble words i.e. words that are there for readability not and executable statement, and the declarative nature of DSLs.
Sprinkled throughout the presentation were examples of some DSL code in Ruby. What I found particularly interesting was the work that Jay Fields has done with Business Natural Languages.
Just remember the three P's (Polish, Preprocess, Parse):
Polish => simple string substitutions to convert nearly ruby to actual ruby
Pre-process => load strings and modify to coerce them into ruby code
Parse => strings into your own language

The End
Another bunch of interesting work he talked about were:
semr (Matt Deiters)
Xample (Ola Bini)

Conclusions
I haven't had much of an opportunity to follow up on these project but I must say they are all rather interesting. DSLs have influenced the way I write code for some time, I just did not know that the coding style I adopted used some of the patterns that Neal described here. That made me feel good :)

Also can't wait for Jays book!

RubyConf 2008 Day 2 - What Every Rubyist Should Know About Threads

2008-11-07T13:22:00.004-05:00

Jim Weirich starts with an introduction of computer architecture, Moore's law, and how the market is looking to build more multicore systems than they are investing in faster CPUs.
Java and Ruby share similarities in their concurrent programming models, although I am not sure how much since JRE 1.5.

He is demonstrated ruby thread code which incremented a nuber:
@amount += 1

We expect that this operation is atomic but there are a few operations here:
@amount #read operation
+ 1 #object creation operation
@amount = (the result) #write operation

With ruby you can create a Mutex object to synchronize a block:
Mutex.new.synchronize do
@amount += amount
end

Jim also demonstrated deadlocks and the ruby script failed. Chain of threads where waiting for each other. Increases when you lock more than one resource at a time. Basically he is saying that multi-threading is difficult.

Its hard because we share mutable memory.

What can we do to write correct multi-threaded code?
Use Erlang => Only Constants, Pattern Matching, Recusion (tail) (Erland eats serial for breakfast!)
Use Clojure => pretty much a functional language. The language is designed to avoid deadlocks.

RubyConf 2008 Day 2 - Rameze

2008-11-07T11:19:00.004-05:00

These are my raw unedited notes:

Luc Castera
His presentation is pretty amusing
He believes that Ramaze is one of the underrated ruby web frameworks
It is modular
There is only one dependency... Rack
ORM-agnostic
Template agnostic
From his perspective the source is Beautiful Code
Bacon BDD - It looks interesting

How is this different from rails?
Action methods accept parameters
#/controller_name/add/1/2
def add(first, second)
Supports regex and lambda routing
It integrates easily with jquery

Something that annoys me, Ariel not Luc, about these web frameworks is all of the scriptlets in the view. link_to for example makes it hard to read.
I, Ariel, don't know that this is better than rails. It seems almost like there is more room to make mistakes.

RubyConf 2008 Day 2 - Fear of Programming

2008-11-07T10:22:00.003-05:00

This was a pretty engaging talk. No slides just us.

Nathaniel Talbott started his talk by asserting that artists have an emotional relationship with their creations. Fred Brooks likened programmers to artists (actually poets) because we both start with a "blank sheet" were we use our skills, knowledge, and imagination to "create" something. Now if Brooks is correct, Nathaniel believes that programmers are also subject to this emotional connection but because we do not tend to think of ourselves as artists, we tend not to explore this part of our lives.

Fear is a "very significant emotion" that prevent us from doing "that thing" but "all fear is legitimate because they are warning signs" trying to protect us from danger. "Fear is to your mind as pain is in your body", your body uses pain to tell you that there is something wrong.

Nathaniel went on to describe how fear hinders our productivity. Here are just some of the fears that he described we face:
Fear of a blank page
How do I start? What do I do?

Fear of the code
Legacy code
Beautiful code. Am I gonna mess this up?
Maybe I will write something that I will not respect and others will not respect me

Fear of not finishing
I am afraid it will not get done

Fear of finishing
Management or lead developers are afraid to call it done and push this out
Its easy to hack away on a side project without publishing it

Fear of the unknown
The big amorphous blob that I cannot conceptualize.

Some of us in the audience added the following:
Fear of not liking what I do
Fear of developing meaningless code
Fear of commitment
Fear of re-invention
Fear rejecting people
Fear of all of the non-programming activities
Fear imagination outreaches my ability

He states that since fear is a warning mechanism than "it is pathetic as a decision maker". Do not rely on your "fear" to make decisions instead rely on more knowledge and wisdom. He said use testing; prototypes; setting boundaries; and worst case scenarios. Nathaniel then polled the audience and I said use pair programming to combat fear. Others said be more afraid of something else however that would probably lead to layer upon layer of neuroses. One individual said that he prays. Nathaniel also referenced a few books that desribe how to deal with fear: "The War of Art", "Art and Fear", and "The Road Less Traveled". The jist of the this part was that big fuzzy problems are harder to deal with than smaller fuzzy problems. So work with smaller fuzzy problems.

His second suggestion which he described as the "ultimate antidote to fear" is Love! Surround yourself with people who love you unconditionally and support your decisions. Its better to make decisions based on the passion that you have for your craft. Pour yourself into the things that you are working on. Be motivated by your passion e.g. I love to solve problems!

Taking your laptop

2008-11-07T10:16:00.003-05:00

I gave The Man a lecture on why he shouldn't bring his laptop to the talks at RubyConf. I said "I don't do it because it distracts me during the talks; it acts as an anchor because if I do not like the talk its harder to leave the room (power cord, LAN cable, etc...); and well its just plain rude!"
Turns out I am a hypocrite. Here I am blogging while I wait for the next talk.

RubyConf 2008 Day 2 - Patterns in Distributed Processing

2008-11-07T09:49:00.003-05:00

Distributed computing and threading have been my favorite topics to learn about over the past year. In general this stuff is just way over my head and I feel like I learn something new every time I attend a talk on these subjects. This conference is filled with all sorts of interesting presentations including one where Mike Perham is discussing a library he created for clustered systems. He gave us a little background on himself and I was impressed to find out that he is responsible for shard support in ActiveRecord.
He seems like a brilliant fellow and is demonstrating some advanced threading concepts, only using distributed machines using DRb. This is an entirely different approach from a NeverBlock, which used Fibers, i.e. continuations, to allow green threads to "work" faster. I believe that based on the code I have seen today, Mike's approach is probably easier to understand and use.
He is also describing "Paxos" and encouraged us to take a look at Google's white paper "Paxos Made Live". Paxos is slow because there is lots of network chatter and Mike decided to head in a less formal direction using a designated "leader" and follower workers. Quote from his blog:

TokenWorker ensures that one process from a group of redundant processes will be elected to perform processing for the next N seconds.
StaticQueueWorker distributes a predefined set of work to a dynamic set of processes every N seconds.

When Brian Geotz discussed multi-threading in Java he seemed really excited about it. This talk would have been better if Mike were a little more energized.

The XP Coaching Paradox

2008-11-05T15:43:00.000-05:00

As a team new to XP, I want for you to coach my team, so that we can deliver valuable features to our customers.
Great, now that I know what our goal is, lets get down to business! However its just not that simple because people are afraid to embrace change for a myriad of reasons. The mistake I regularly make is reacting when I loose my patience or when someone says something that runs contrary to pure XP. The dogmatist in me converts anger into logic and I refuse to stop arguing until I am able to make them look foolish.
Although Emperor Palpatine would encourage you to "release your anger" that behavior is simply unbecoming of a Jedi and is just not the right thing to do! It hurts peoples feelings and brings down the teams morale.
Today was a great step forward in my life as a professional coach. I did not allow my emotions to get in the way of what I was doing. I listened to what my customers where saying without prejudice and reserved my comments when I heard someone say that testing was a waste of time.
As a coach you have to let people make mistakes. Its all part of the game.

Characterization Testing

2008-11-05T15:13:00.002-05:00

Test that code

Michael Feathers introduced the concept of using characterization testing in order to provide code coverage for untested legacy code. This technique is essential for anyone working with existing production code because it ensures that the external behavior of the system under modification is not effected as it undergoes internal changes. The problem with this technique is that it turns people off to testing despite the fact that this technique often helps to identify design problems in the system under test.

Unit Testing Is Stupid

On one occasion I was paring with a developer who was a staunch supporter of "test automation" but did not believe in unit level tests. His organization however mandated that every developer write unit tests, so he came to my team for help with writing tests for the system. I started by writing the first test....
def test_do_it
assert_equal "no clue what you do", @sut.do_it
end
... he said, "What are you testing? That really doesn't make any sense". I responded by saying, "I don't know what this class is supposed to do, but I can find out what it actually does by executing it". He scowled furiously at me but I executed it and low and behold there was an error! In disbelief he exclaimed, "what nil object?!?" Yes, we actually found a bug by writing a characterization test! This sparked a conversation among a few team members and it turned out that a misunderstanding of what his class was supposed lead to a bug.

Well not really. He ran off into his cave again writing code without tests in order to fix this problem. However he never came back to me. When I ran into him again I asked how testing was going and he gave me the same spiel about how unit testing is not important. Really? Even though it lead to discovering a BUG!
On other projects where there is just a ton of legacy code and I have to add or correct the existing behavior, we often spend a few hours just writing characterization tests. When I am pairing with someone relatively new to TDD they hate it. Lets just face it, test-last development is tedious. Shouldn't that be reason enough for people to prefer TDD?

A place for everything

2008-11-04T19:55:00.000-05:00

Switiching from project to project is one of the most rewarding things about being a consultant but it is also extremely frustrating. Every few months I found myself asking people, where may I find X? When I would verbalize my frustration, my customers would dismiss it saying that its part of the process of "getting up to speed", however I would prefer to spend my time implementing features. Why must I be burdened with this accidental complexity?
That's one of the things that I love about Rails. What stands out to me immediately is how everyone seems to know where to find X.
Rails encouraged me to organize my Java web projects in a way that is intuitive to people. The results have been mostly positive; easier to understand file structure; increased diligence in using domain language for naming; common names for related features; easier to understand the relationship between view components and "server-side" code; and reduced complexity of our configuration files. I highly recommend that you go back to basics and start simplifying your code base structure!

We're special... the antipattern

2008-10-31T18:51:00.003-04:00

Finally someone has recognized this agile adoption anti-pattern. The agile community has gone from being risk takers who influence and embrace change to [INSERT_EXPLETIVE_HERE]
http://www.ibm.com/developerworks/blogs/page/ambler?entry=adoption_antipattern_we_re_special

Dependency Injection Sucks

2008-10-22T20:51:00.001-04:00

It depends. If you write terrible code it does.

http://googletesting.blogspot.com/2008/10/dependency-injection-myth-reference.html

Calculating Capacity

2008-10-18T07:26:00.008-04:00

If you have ever seen the film Office Space, you are familiar with the scene where the Bob's are interviewing Peter trying to find out how he contributes at work. In that scene he says, "I'd probably, say, in a given week, I probably do about fifteen minutes of real, actual work."
Did you laugh when he said that? I know I did, but it begged the question, how much work do I actually do in a day? If I do not know how long it took me to do something then am I really providing honest estimates?

Our team uses a simple formula to determine how much work we could do in a week:
one_week_capacity = (total_number_of_developers/2) * total_days * hours_per_day

total_number_of_developers/2? We practice pair programming. If your team doesn't then there is not one there to prevent you from slacking. You really are 50% productive.

total_days? Normally you have about 5 days in a week but you should not assume you will have 100% of your time available for working on production code or that your estimates where accurate. Calculate capacity using 70% of your work week (3.5 days instead of 5), that will allow plenty of room for incorrect estimates.

hours_per_day? Paring is usually maxes out at about 6 hours a day. The other 2 hours should be allotted to take breaks, respond to e-mails, attend meetings, etc...

Compare your estimates to your actual completed work every iteration. Once you are able to determine how much work you are doing, what you can do is easier to calculate. This computation has been pretty accurate for me over the past few years. Give this a try and let me know how it works for you!

Timeout::TimeoutError

2008-10-16T21:33:00.003-04:00

This was annoying
def test_timeout_error
Timeout.expects(:timeout).with(any_parameters).raises(Timeout::Error.new)
assert_raise(Timeout::Error) {
some_crazy_code()
}
end

1) Error:
test_timeout_error(TimerTest):
ArgumentError: wrong number of arguments (0 for 1)

Here is the fix!
def test_timeout_error
Timeout.expects(:timeout).with(any_parameters).raises(Timeout::Error)
assert_raise(Timeout::Error) {
some_crazy_code()
}
end

UPDATE: WARNING WARNING WARNING
Do not use Timeout::timeout in Ruby 1.8! IT DOES NOT WORK RIGHT!
http://blog.headius.com/2008/02/rubys-threadraise-threadkill-timeoutrb.html
http://ph7spot.com/articles/system_timer
http://www.mikeperham.com/2009/03/15/socket-timeouts-in-ruby/

Sorry folks!

2008-10-15T23:49:00.002-04:00

I have canceled my VPS and am in the process of transferring all of my hosting to Google applications. I will miss you Rimuhosting however one day I will come around to slicehost.

Java is not Object Oriented.

2008-10-06T21:03:00.002-04:00

Dave Thomas has made some interesting statements about Java being a class-oriented programming programming language but here are a few interested blog posts about it being "Library-Oriented":
Neal Ford on http://memeagora.blogspot.com/2008/10/library-oriented-programming.html
Eric's blog http://www.lispcast.com/drupal/node/55http://www.lispcast.com/drupal/node/55

Dwellmen on GWT!!!

2008-10-04T22:12:00.001-04:00

My colleague Daniel Wellman has written an introductory article on GWT. Enjoy!

Internal & External DSLs in Java

2008-09-28T22:25:00.002-04:00

I attended Venkat's talks at NFJS and I was really excited about what Groovy brings to the table for helping you be a more productive Java programmer. He started a series for DSLs in Java and I found this article to be very interesting.

joel on ruby

2008-09-27T20:38:00.000-04:00

Kent Beck keynote at Rails Conf 2008

2008-09-27T13:58:00.004-04:00

KB's keynote is a retrospective of his experiences as a leader in the industry.

I don't like reading

2008-09-23T23:08:00.004-04:00

Beck on Test Driven Design

2008-09-22T22:04:00.000-04:00

http://www.threeriversinstitute.org/AbstractVsConcreteParameters.html
This is an interesting blog post. After reading it, I did asked myself, which of these approaches leads to a better design?
Take the example that Beck mentions on the JUnit mailing list, he suggests to "objectify" the integers into a SocketConnection:
class Client { Client(int address, int port) { this(new SocketConnection(address, port)); } }
He then goes on to say that it will be easy to inject an impostor and then you will have more control over the interaction between a socket connection and the client. The problem however is the "cost of modifying the client" because of the lack of flexibility one has when working with a language like Java.
This is not a problem when working with a dynamically typed language like Groovy or Ruby because clients are free to open classes, which makes it easier to remove dependencies. This eliminates the need to make any changes to the client code in order to make it more "testable". This leads me to the conclusion that "good design" changes depending on the language you are using. It seems to me that the more flexibility you have the less it matters how concrete things are in the system... NOT!
Using a flexible language does not excuse you from authoring tightly coupled code. This is something I often observe in CRUD applications because they are generally not designed using a tell don't ask, demeter abiding, publish-subscribe style. If you are lucky the team may use life-cycle hooks like before_save or @PrePersist but chances are your controllers are acting as mediators instead of view components.

RubyConf 2008

2008-09-10T23:27:00.002-04:00

I am going back to MCO... MCO... MCO...
... Did I mention I am back working on RoR? :-)

I really should twitter...

Am I an idiot?

2008-09-10T23:14:00.004-04:00

The thing about the internet is that your comments are immortalized.
http://www.theserverside.com/news/thread.tss?thread_id=36509#184443
I have come a long way from BUFD...

XP without TDD?

2008-09-06T15:53:00.004-04:00

I've been reading a lot of articles and presentations about the state of "agile" adoption. One that caught my attention was "Just Ship, Baby". In it Kent Beck writes:

I had an idea for another little tool yesterday. I wrote it without any tests, just to remind myself that I could still program without a net if I had to. I really didn’t like the feeling of not having any tests, especially when the algorithm got hairy. I’m not sure my code works in all cases. But you know what? I shipped. Turns out it isn’t that cool of an idea, and I’ll drop it. Total cost for that answer—3 hours.

What no TDD? At first, I was appalled but after reflecting on it, it seemed all he did was spike a solution in three hours, which I believe that is a perfectly healthy agile practice. However, this article like many other presentations is a sign that the "agile" community is undergoing a transformation.
No less than ever are we willing to dive in head first to make an impact. I once thought that we were a small band of engineers trying to save ourselves from the waterfall only to find that in the end we are producing waterwheels. How did this happen?

NFJS 2008 - Princeton NJ Day 3

2008-08-13T20:21:00.003-04:00

Structuring concurrent applications in JDK 5.0 (Brian Goetz)
This was an awesome talk. I don't know about you but I want to write multithreaded applications now!

Groovy, The Red Pill: Metaprogramming, the Groovy Way to Blow a Buttoned-Down Java Developer's Mind (Scott Davis)
This session was great because Scott is an engaging speaker. He tried new things at the request of the audience. Fly by the seat of your pants. Lots of fun.

Java Persistence: Approaching the Silver Bullet (Mark Richards)
This was pretty much an overview of JPA and the limitations, which if you are familiar with Hibernate, you already know. Mark is a great speaker and this was an extremely interactive session, he used code samples and has just a ton of knowledge and experience around different ORM solutions.

EXPERT PANEL DISCUSSION
I wish we would have had more "audience" questions. This was mostly a talking heads session.

Promoted to Technical Lead. Now what do I do? (Mark Johnson)
Last talk of the Sunday. I was ready to go home but I wanted to sit through this talk. I was hoping to learn a few soft techniques here to be a better tech lead. I would have liked to get a little more role play to try and tease out some real life scenarios.

Mock Objects Not States

2008-08-11T20:52:00.002-04:00

The dynamic duo back again... http://www.infoq.com/presentations/Mock-Objects-Nat-Pryce-Steve-Freeman.

A little taste:

Smell #1: the test exposes the internal implementation details of the object tested. It's clear that object encapsulation is broken.

Smell #2: passing too much information to the object tested with constructors having too many parameters. The object tested has too many dependencies, and it may be time to break it up in several smaller objects.

Smell #3: mock everything. One wants to mock dependencies and peers, but not value objects.

Smell #4: the tests just replicate production code. Code should not be replicated.

Smell #5: one needs to mock an object he cannot replace. External objects can be used, but cannot be mocked.

Smell #6: one needs to mock a concrete class. The tests are meant to verify relationships between objects, not to test a specific instance of an object.

NFJS 2008 - Princeton NJ Day 2

2008-08-11T20:22:00.003-04:00

Agile Test Driven Development With Groovy (Jeff Brown)
I confess that I did not really like Groovy before coming to this conference. I like Ruby's syntax better and Groovy reminded me too much of JavaScript. However this talk made me once again appreciate dynamic languages and how they are easier to test with than compiler checked statically typed languages.

Another interesting thing about this talk was learning how to use Groovy to test my Java code. Pretty cool.

Caring about your Code Quality (Venkat Subramaniam)
This talk was pretty much an affirmation for me. If you write crap code. You will get crap code.

The Java Memory Model (Brian Goetz)
HOLY COW! I am the worst multi-threaded Java programmer ever. This is an awesome talk and you must attend it!

Software Development Risk Management (Mark Johnson)
I was hoping this would have been more hands on. This is not a technical talk.

NFJS 2008 - Princeton NJ Day 1

2008-08-08T23:29:00.005-04:00

Just wrapped up my first day at NFJS in Princeton. I attended a few talks, which I liked for the most part.

Give it a REST (Brian Sletten)
I resisted REST for a long time but Jason and Dan got me to embrace the concepts. This talk helped me put a nail in my SOAP/WSDL coffin. If you are not familiar with REST I recommend attending this talk.

Evolutionary SOA (Neil Ford)
Its clear that Jim Webber and Neil dislike using ESB tools. This talk has entertaining slides but I think a combination of Neil seeming tired and a low energy audience made for less interesting experience.

Know your Java? (Venkat Subramaniam)
This was a lot of fun. Venkat is a really engaging speaker and was generous enough to give Jason and I books! Thanks Venkat!

Keynote (Neil Ford)
This talk was given by the Neil we know and love. He demonstrated how the teachings of philosophers like Galileo and Plato apply to today's software development projects. Lots of the content was an introduction to agile software development but given the audience, I think that it was appropriate to elaborate on it.

Another TDD Book?

2008-08-06T22:06:00.002-04:00

Steve Freeman and Nat Pryce are writing what I believe will become the new bible of TDD. It looks like they have been releasing a chapter a week online and I recommend you join them for the ride.

More GWT Testing

2008-08-06T21:55:00.003-04:00

Dan is on a roll this month with GWT testing. In this blog post he revisits testing JSON parsing using JavaScript overlay types. Enjoy :)
http://blog.danielwellman.com/2008/08/testing-json-parsing-using-javascript-overlay-types-in-gwt-15.html

solipse (Eclipse on Solaris)

2008-07-28T19:13:00.003-04:00

Congratulations to Tim Myer and Hugo Garcia for their valiant efforts getting Eclipse running on Solaris codename solipse!

GWT Testing Blog Posts

2008-07-27T23:03:00.005-04:00

One of the smartest and likable fellows I know, Daniel Wellman, is being publish for his work with GWT(Google Web Toolkit). It all started with this blog post:
http://blog.danielwellman.com/2008/06/strategies-for-testing-gwt-widgets-and-view-components.html
Enjoy!!!

I've switched

2008-07-27T17:01:00.005-04:00

I took my family on a shopping spree this weekend. Our last stop was at Best Buy where my wife gave me a choice between:

and

Guess what I picked?!?

How Ruby made me into a better Java developer

2008-07-25T14:35:00.002-04:00

Like most programmers, I have had the pleasure of being exposed to multiple programming languages and frameworks. In some way all of these experiences have influenced the way I think about testing and challenging my beliefs about "good" design. After reading the Pragmatic Programmer for the second time, it occurred to me that this is happening because I...

Invest Regularly in Your Knowledge Portfolio
Make learning a habit. [Thomas and Hunt]

I started my career as an ASP classic VB 6 developer. Learning Java taught me that I should really think more like an OO programmer. It also exposed me to design patterns and forced me to realize that the code I was produced was actually a big mess. Java changed the way I was doing things. I started to use patterns like; proxies; late binding; interfaces; and factories. This greatly improved my ability to test production code and helped me reduce the outrages scriptlet code found in the web pages I was working on.
Then came C#. The transition from Java was not so difficult but I did learn more about delegates, data binding, event driven programming, as well as presentation patterns that were not MVC. It did not seem to make quite as much of an impact on the way I wrote Java apps. I did however find myself asking questions about how useful EJBs where and whether or not a DTO made any sense! I also longed for a "using(closableResource)" so that I would not have to write so many try/catch statements. MbUnit also really impacted the way I thought about testing and how refactoring test code was just as important as production code.
Then there are more complex things like SOA based applications using SOAP/WSDL and how it made me think about designing reusable components using better interfaces. I also learned a lot about how really useful adapters, bridges, and facades mitigate integration nightmares.
Now I find myself reflecting on how Rails influenced the way I approach Java Web applications and how it changed the way I think! So much so that the next few posts are going to be about:

Component/Integration Testing
Unit/Micro Testing
Test Driving UI
Using conventions in my configuration
Simplifying the way I use Hibernate
Using composite views with partials
Meta programming and annotations
Action mappings
Simplifying Models

I hope that you find the topics interesting and please do not be put off because I am writing about RoR. I am not one of those people who now hates Java and believes that Ruby is better, I am just a believer in learning and growing.

HELP! My project has no tests!

2008-07-15T00:41:00.003-04:00

There are a few ways that you can introduce tests if your team is in this situation.

Thorough Manual Verification!

Hire, outsource, or distribute the work of manual functional testers. Make them run a full suite of regression tests with every build.

Automate It… ALL OF IT!

Convert your current manual functional or exploratory tests scripts to automated “end-to-end” tests.
Write "end-to-end" system integration tests that "prove" everything really works. For example, write some tests that somehow verify the jobs extract data from a mainframe and then import them to your RDBMS.
Install code coverage tools and run reports. Get all of the developers to write tests until they see 80-100% coverage!

The Pragmatic Approach…

Slowly add automated tests which, run with every build of your application.
Write focused automated tests to help identify the root cause of bugs that are currently in production.
Identify the areas of your application that “break” the most and prioritize them testing/fixing them as features.
Write focused automated characterization tests for the code/features you are going to change.
Write focused automated tests only for the code/features you are working on.
Use manual exploratory testing to validate that the features were implemented correctly.

Results
The problem with the thorough manual approach is that it is expensive to coordinate and execute. In addition to that, development slows down so revenue generating features don’t make it production fast enough to help pay the salaries of all of those testers.

Then there is the thorough automated approach. Like its manual counterpart, it is a tedious exercise, which often discourages developers from writing “good” tests that actually provide any value to the product owners. It is also an extremely difficult feat to accomplish because these systems were not built to be testable in the first place. The end result is often a collection of “tests” that do not really verifying if the system is doing the right thing in order to increase statistics.

There is little return on investment for features that are either; stable and running in production with no reported bugs; or not used enough for anyone to notice if any bugs exist! That’s why I recommend the pragmatic approach. Keep your tests focused and small, don’t feel obligated to write automate tests for every single part of your application; some things just don’t break once you’ve performed exploratory tests.

Not only does it allow you to start providing coverage for your application, but it also immediately improves your ability to provide working features. This will not only increase your teams’ confidence and self worth, but you’ll be making money for your product owners in the process!

I'm angry

2008-07-12T15:47:00.006-04:00

I recently received some feedback from a few of my esteemed coworkers. They said that my posts are interesting because they seem to be filled with quite a bit of anger. They also gave me some practical advice like, “run your posts through grammar checkers so that you don’t sound like a tool”.

After reflecting on the former statement, I realized that I am filled with anger! Like most of my fellow XPers, I’ve had to endure years of suffering under a regime of SDLC monkeys! Now this pain is manifesting itself as wrath and I have vowed to rid the world of these wankers one by one.

From this day forward, I bring you Angry XP!