Will we only create and use dynamic languages in the future?

January 7, 2012

Since I’ve playing with some dynamic languages (Ruby and Clojure), I have been thinking about why would anybody create a new static typed language?! And I didn’t get the answer.

I started programming in Visual Basic and I taste its roots, which are almost all full of procedure commands (bunch of do, goto and end), then I moved to C#, sharper it changes the end’s for }’s and give us a little more power based on some premises: we can treat two different things in the same way, polymorphism. The last static language, but not the least, I used (and I use it) Java, abusing of his new way of treating a set of things equality, the interfaces and using its “powers” on reflections.

Although when I started to use Ruby I saw that I could treat a group of things equality without doing any extra work. I still need to code models and composed types, even though we can create or change them dynamically using “real power” of metaprogramming.

When I start to study and apply the Clojure and its principles, my first reaction was the rejection, how can I go on without my formal objects, how can I design software without a model in the head and so on. I wasn’t thinking about how actually I do software, currently I use TDD to design software and I don’t think what models I need to have, I do think in terms of “what I want”. At minimum, Clojure make me think about, do we really need object to design software?! .  A three days ago I saw an amazing video about similar thoughts: Some thoughts on Ruby after 18 months of Clojure.

Summarising: With my limited knowledge of theses languages, let’s suppose we use a function (which we don’t have source code) and we want to do something before that function is executed (intercept) using: VB I’ll need to check every single piece of code which we call this function and call another one, in Java we can use a AOP framework, in Ruby we can use the spells of metaprogramming. It seems that some frameworks, patterns and extra work aren’t needed more because of this dynamic language evolution.

My conclusions using dynamic languages (Clojure/Ruby) for now it’s: I write less code and reuse them more easy, so I don’t see any reason to create/use a new static typed language, would you see any motivation to do that?

PS: When I use C# (.Net Framework 1.3 – 2.0) it was not so super cool as today.


Clojure resources

November 29, 2011

Always that I start to learn a new language, I promise to keep the best resources links I found, but it never works. This post suppose to be updated often. Any broken link or suggestion, just comment and I’ll try to fix, add or remove it.

Links, tutorials, guides, documentations, screencasts and etc.

  1. Clojure official site
  2. Installing Clojure, clojure-contrib and setup EMACS.
  3. VIM for Clojure
  4. Quick-start with examples
  5. VIDEO – Great short introduction videos for Clojure!
  6. VIDEO – Introduction to logic programming with Clojure
  7. VIDEO – Clojure for Java Programmers 1 of 2
  8. VIDEO – Functional programming by UCBerkeley 
  9. VIDEO – Great tutorial for Clojure focused on concurrency
  10. Try code clojure online
  11. Leiningen tutorial for beginners
  12. Midje – A test framework for Clojure
  13. Clojars – Community repository for open source clojure libraries

Books


Testing JavaScript with Jasmine and Jessie and node.js

August 22, 2011
Testing

Testing JS, can you imagine?

Javascript

JavaScript is a prototype-based, object-oriented scripting language that is dynamic, weakly typed and has first-class functions. It is also considered a functional programming language like Scheme and OCaml because it has closures and supports higher-order functions. Cool language isn’t? A new feeling inside me tells me that everything (related to I.T.) I would like to learn I should start writing a tests. However I thought that JavaScript test was stucked on Alert windows and then I found out Jasmine framework.

How could we write tests to JavaScript?

Using Jasmine in a BDD style.

describe("Jasmine", function() {
  it("makes testing JavaScript awesome!", function() {
    expect(yourCode).toBeLotsBetter();
  });
});

To run it and get feedback you have some options whose I take two: seeing the html file on browser and seeing the terminal result as rspec way. We will do the second way. For that we will use: node.js, npm and jessie.

node.jsevented i/o server (and also you can use it as an interpreter) for javascript vm (specifically v8)
Installing node.js

git clone --depth 1 git://github.com/joyent/node.git
cd node
git checkout v0.4.11 #opt, note that master is unstable.
export JOBS=2 #opt, sets number of parallel commands.
mkdir ~/local
./configure --prefix=$HOME/local/node
make
make install
echo 'export PATH=$HOME/local/node/bin:$PATH' >> ~/.profile
echo 'export NODE_PATH=$HOME/local/node:$HOME/local/node/lib/node_modules' >> ~/.profile
source ~/.profile

npm – node package manager, as its own name suggest. You can use it to install and publish your node programs. It manages dependencies and does other cool stuff.
Installing npm.

curl http://npmjs.org/install.sh | sh

jessie - Jessie is a Node runner for Jasmine. It was created to provide better reporting on failures, more modular design, easier creation of formatters and optional syntactic sugar.
Installing jessie.

npm install jessie

With all these binaries on your path you can just run your tests from terminal typing:

jessie folder_with_specs/ -f nested

In fact I’ve been using the gitub and jessie to learn and apply javascript.


RSpec and Watir to test web applications

August 19, 2011

Testing is cool

Software testing

Software testing is an investigation conducted to provide stakeholders with information about the quality of the product or service under test. Software testing can also provide an objective, independent view of the software to allow the business to appreciate and understand the risks of software implementation. Test techniques include, but are not limited to, the process of executing a program or application with the intent of finding software bugs (errors or other defects) – Wikipedia

The main intend of this post is, introduce you to UI tests over some ruby toys. In fact you could create an entire project (new) in ruby just to test your legacy web project. It’s cool, you can learn new language and work for the improvement of your legacy product. If you are totally new for ruby maybe a ruby overview can help you. (or might confuse you more)

Installing ruby, watir and rspec

Instead of installing the ruby directly, we are going to install the RVM (Ruby Version Manager) to then install any ruby we need. The steps described here were made on Ubuntu 11.04. On your terminal do the magic to install RVM.

bash < <(curl -s https://rvm.beginrescueend.com/install/rvm)
echo ‘[[ -s "$HOME/.rvm/scripts/rvm" ]] && . “$HOME/.rvm/scripts/rvm” # Load RVM function’ >> ~/.bash_profile
source .bash_profile

And from now on, your life will be better on ruby interpreters versions. Let’s install the ruby 1.9.2. (terminal again)

rvm install 1.9.2

And if we want to see the rubies installed on our machine?

rvm list

And now, how can we chose one ruby to work on the terminal session?

rvm use 1.9.2

For the test purpose we will use Watir and RSpec, great tools for testing, make fun with BDD and the best thing is install them it’s very easy.

gem install watir-webdriver
gem install rspec

Hands-on

Since we have all things installed, we can move for the example. The feature I want to test is the search system of  Amazon. Being more precise, I want to search for ‘Brazil’ and see if the ‘Brazil on the Rise’ is within the results as I want to be sure when I search for ‘semnocao‘ the Amazon doesn’t provide any result. Now, we can write the spec.

require 'amazon_page'

describe AmazonPage do
 before(:each) do
   @page = AmazonPage.new
 end
 after(:each) do
   @page.close
 end
 it "should show 'Brazil on the Rise' when I query for [Brazil]" do
  @page.query 'Brazil'
  @page.has_text('Brazil on the Rise').should == true
 end
 it "should bring no result when I search for [semnocao]" do
  @page.query 'semnocao'
  @page.results_count.should == 0
 end
end

The specification is very simple, it will create a page before each test calling and close the page after each test calling. There is only two tests: test when you search for Brazil  and  when you search for semnocao. We will design the tests using page object pattern. The class bellow is the page which represents the Amazon page and all testable behaviors should be inside of it.

require 'watir-webdriver'

class AmazonPage
 def initialize
  @page = Watir::Browser::new :firefox
  @page.goto 'http://www.amazon.com'
 end
 def close
  @page.quit
 end
 def query(parameter)
  @page.text_field(:id=>'twotabsearchtextbox').set parameter
  @page.send_keys :enter
 end
 def has_text(text)
  @page.text.include? text
 end
 def results_count
    if @page.text.include? 'did not match'
     0
    else
     @page.div(:id=>'resultCount').text.split(' ')[5].gsub(',','').to_i
    end
 end
end

To run this you just need to type on your terminal.

rspec spec/

The final code can be downloaded or viewed at github.

Additions

  • We could improve our story readibility  with Cucumber.
  • We could send the browser execution to an Xvfb server. (A.K.A. running headless) The browser pops up really bothers me.
  • We could integrate it with our CI.
  • We could design a base Page class for provide common operations as mixin or something

ps: the post was very inspired by KK post and Saush.


Acceptance testing on Fitnesse using slim test system

June 27, 2011

What is Fitnesse?

  • It’s a software development collaboration tool.
  • It’s a software testing tool.
  • It’s a wiki.
  • It’s a web server.

This tool provides a way for the BA’s and/or customers write their acceptance testing on wikis and better than this, they can run theirs tests and see if it fails or pass right on the page. Install Fitnesse it’s very simple, you just download and execute. The fitnesse architecture provides two types of test system: slim and the well-known fit. For this tutorial I’ll use the slim.

The hands-on

Scenario: Given that I have the input1 and input2 Then the output Should Be input1 plus space input2. So let’s express the acceptance testing of this feature (or behavior if you want). In Fitnesse we can express this using the decision table, others examples of places to write tests are query table, script table, library table and etc.

|it should print guaqmire|
|input1|input2|output?|
|you|are|you are|
|family|guy|family guy|
|tests|enough|tests enough|

Explaining the table, the first line is the name of the fixture, the second line contains the inputs and outputs names and from the third line on it’s filled with testing data. The output table should look like this:
Let’s setup the wiki-page to it became runnable, edit the page and put these parameters on the page.

!define TEST_SYSTEM {slim}
!define TEST_RUNNER {C:\fit\slim\rubyslim\lib\run_ruby_slim.rb}
!define PATH_SEPARATOR { -I }
!define COMMAND_PATTERN {ruby -I %p %m}
!path C:\fit\slim\rubyslim\lib\
!path C:\fit\ruby\prj\

The first line is setting TEST_SYSTEM to configure fitnesse to use the slim protocol instead of default fit. As we will use slim and ruby, we’ll use the rubyslim library. The second line is setting the TEST_RUNNER to use the ruby slim. Third line defines the PATH_SEPARATOR, used by the COMMAND_PATTERN to separate paths. The fourth line is configuring the COMMAND_PATTERN that will execute the test itself, the two parameters %p (receives all the paths from the page and its ancestors) and %m (the fixture itself) are used to correctly perform the test. The lines with path just informs to fitnesse where it can found the libraries and the runtime files.

And now you can run, is it fails? Good, now let’s programming it in ruby, if you are a newbie ruby as me, your code might be something like this.

module Fixtures
  class ItShouldPrintGuaqmire
   def set_input1 input1
    @input1 = input1
   end
   def set_input2 input2
    @input2 = input2
   end
   def output
    "#{@input1} #{@input2}"
   end
  end
end

Ohh it continues to fail, shame on me. As you can see at the code, I put the fixture inside a module called Fixture, so we need to inform the fitness what module/package is my fixture and we can do that by a table.

|Import|
|Fixtures|

This special table only  configures where is the fixtures. Now let’s see the entire code for fitnesse wiki.

!define TEST_SYSTEM {slim}
!define TEST_RUNNER {C:\fit\slim\rubyslim\lib\run_ruby_slim.rb}
!define PATH_SEPARATOR { -I }
!define COMMAND_PATTERN {ruby -I %p %m}
!path C:\fit\slim\rubyslim\lib\
!path C:\fit\ruby\prj\

|Import|
|Fixtures|

|it should print guaqmire|
|input1|input2|output?|
|you|are|you are|
|family|guy|family guy|
|tests|enough|tests enough|

Running the tests should show

Bonus round – Fitnesse using slim protocol in Java

In fact to make it runnable in Java it’s easier, you don’t need any TEST_RUNNER or COMMAND_PATTERN in your wiki page, since Java it’s default for fitnesse and your final wiki should look like this:

!define TEST_SYSTEM {slim}
!path C:\fit\java\prj\fit-slim-java.jar

|Import|
|br.com.leandromoreira.fixtures|

|it should print guaqmire|
|input1|input2|output?|
|you|are|you are|
|family|guy|family guy|
|tests|enough|tests enough|

And your Java code can be something like this:

package br.com.leandromoreira.fixtures;

public class ItShouldPrintGuaqmire{
  private String input1;
  private String input2;
  public void setInput1(final String i1){
   input1 = i1;
  }
  public void setInput2(final String i2){
   input2 = i2;
  }
  public String output(){
   return input1 + " " + input2;
  }
}

Real world

Usually the real world projects requires a lots of libraries on path, setup pages and more than just decision table to write tests. For instance, you can see that use fitnesse with slim seems more portable , less coupled with runtime and easier to implement too. In the real world you also create wiki for the project and suite test page for stories and organize all your imports and configs on project level, when you are composing a wiki on fitnesse you can take advantage of the fact that all the pages extend the configs from theirs ancestors, so you can have a better project wiki and managable test suite pages.

Update – Issues with Ruby 1.9.x

If you are trying to use the ruby 1.9.x you will have some issues the first one is: require ‘jcode’ issue, I tried to solve it but then it started to show another error list_deserializer.rb:1:in `<’: comparison of String with Float failed (ArgumentError)’.  Since I’m not (still) a ruby guy I don’t know how to fix it.


Follow

Get every new post delivered to your Inbox.