Monday, June 21, 2010

Testing with Rspec, Cucumber, Selenium, Watir & Buzz around BDD, TDD

I was lucky to be working with some folks this past week, who are working on a bleeding edge commerce framework and this particular blog is more on the testing frameworks for front end.

I will soon have an article on building a front end store using ROR for Websphere commerce and it will be really useful to automate the test scripts using RSpec and one of the automation tools out there.

This is meant to be 101 for these concepts and I have added links below for deep diving.

BDD and TDD are paradigms essentially bringing the prominence of writing test cases before development and also making it easier on non coders to understand the test cases.

TDD: Test driven development
1. Writing automated test scripts before actually starting to write codes.
2. It is a great idea using any programming language but traditionally development with languages such as Java was pretty high hence it was skipped as the larger development life cycle was blamed for it.
But It makes great sense for using this approach for ROR (Ruby).
3. Test driven development brings lot of clarity to the design in the very early stage of the development cycle.


BDD: Behavior Driven Development
1. It extends the concept of the TDD and takes it one level further as it makes writing test scripts in a very expressive way and no programmatic way.
2. It really helps non programmers (BA, QA, PM) to understand the test cases as they are expressed in a simple English like language.
3. Using 'should' when describing the behavior of software to help clarify responsibility and questioning the requirements.
4. Using 'ensure' when describing responsibilities of software to differentiate outcomes in the scope of the code in question from side-effects of other elements of code.
5. Using mocks to stand-in for collaborating modules of code essentially stubbed out without the actual implementation.

e.g. RSPec, Cucumber

Selenium: Selenium IDE and Selenium RC. (Remote Control)

Selenium IDE provides automated way of recoding tests from a Firefox plug in and it has a powerful feature to validate tests by providing several commands to assert the results. It also provides a powerful mechanism to export the test case into a programming language such as Java, Ruby (RSpec),Perl, .etc.

Selenium RC: is a tool that allows you to launch browser sessions and run Selenium tests against those browsers.
To do this, the Selenium RC server acts as an intercepting proxy for the browser

Selenium-IDE does not directly support:

* condition statements
* iteration
* logging and reporting of test results
* error handling, particularly unexpected errors
* database testing
* test case grouping
* re-execution of failed tests
* test case dependency
* screenshot capture of test failures

Flash is not supported as a part of the Selenium-IDE but there is a flash extension for Selenium Flash and it also requires changing the actual Flash action scripts to add methods to be called from Selenium. It is not a very good practice.

The results from the tests can be verified by connecting from the database.

Watir: Watir is automated testing framework. It does not have a IDE of it's own but there is a testwide recorder that can be used. A combination of RSpec and Watir really makes very readable test scripts. It offers Flash support on firefox but I could not find a lot of documentation around this. So I have my doubt's around automating Flash components.

Cucumber is designed to allow you to execute automated integration tests. It is a tool for implementing Behavior Driven Development.It can work in Conjecture with Rspec.

Each feature is expressed as a Give\When\Then

Given: Preconditions to be filled.
When: This section defines what feature does (i.e., the behaviour, the steps).
Then: Testable out come that can be validated.

Thursday, June 17, 2010

Character Encoding and Commerce

Character Encoding 101:

The "charset" parameter identifies a character encoding, which is a method of converting a sequence of bytes into a sequence of characters. This conversion fits naturally with the scheme of Web activity: servers send HTML documents to user agents as a stream of bytes; user agents interpret them as a sequence of characters. The conversion method can range from simple one-to-one correspondence to complex switching schemes or algorithms...

Reference: Section 5.2 Character encodings of the HTML Document Representation W3C Recommendations

Character encoding tells the browser and validator what set of characters to use when converting the bits to characters.

Types: what does this mean, there are different standards of character set encoding
You see various encoding types

Traditional ASCII is 7 bits and has limited character representation.

Even though UTF-8 is one of the most popular some of the old browsers might not support hence we used to use ISO-8859-1 encoding in some pages.

windows-1252 :
Windows-1252 is a character encoding of the Latin alphabet, used by default in the legacy components of Microsoft Windows in English and some other Western languages
ISO-8859-1 :
UTF-8,UTF-16,UTF-32 :
Unicode is an international character set standard which supports all of the major scripts of the world, as well as common technical symbols.
Unicode transformation unit and each character is store in 21-bits so depending on each of these UTF types it is stored as a multiple of 8 bytes
e.g. UTF-8 , it could be saved in upto 4 bytes.


In the Java programming language char values represent Unicode characters. Unicode is a 16-bit character encoding that supports the world's major language
UTF-16 (Java).


The language table has a ENCODING column that specifies the encoding for language

select encoding from language where language_id=-1;

From end in JSP:
Character encoding

We set the character encoding to UTF-8 as this is what is present in the DB for language encoding.


Form Submit: In commerce what ever is specified in front end should match with what ever is specified in the encoding attribute of the language table.

select encoding from language where language_id= language passed in the command context.

e.g. If you need the character encoding to windows 1252, you can do that in the session while executing SQL statements.


Database Client:

I use today and for the client to show the correct characterset, we have modified.


Good reference URLs: