Tuesday 3 April 2012


Rails 3 + Rcov Test Coverage
For the first time in a long time I added a new category to the blog. The new category is "Ruby/Rails Test Coverage" .
Writing tests is simple, but I wanted to make sure I had good coverage. This led to me to rcov which does a good job of running my tests and showing me a nice HTML output of the coverage. It was still a pain to go and run rcov and hunt down the report .
So I did some searching and ran across a nice rake plugin called rails rcov that does it all for me. Now I can run rake test:test:rcov from TextMate and see all my tests run and view my coverage.
I created the following rake file in lib/tasks/coverage.rake:
namespace :coverage do
 
  task :clean do
    rm_f "test/coverage"
    rm_f "test/coverage.data"
    Rcov = "cd test && rcov --rails --aggregate coverage.data -Ilib \
                   --text-summary -x 'bundler/*,gems/*'"
  end
 
  def display_coverage
    system("sensible-browser test/coverage/index.html")
  end
 
  desc 'Measures unit test coverage'
  task :unit => :clean do
    system("#{Rcov} --html unit/*_test.rb")
    display_coverage
  end
 
  desc 'Measures functional test coverage'
  task :func => :clean do
    system("#{Rcov} --html functional/*_test.rb")
    display_coverage
  end
 
  desc 'All unit test coverage'
  task :all => :clean do
    system("#{Rcov} --html */*_test.rb")
    display_coverage
  end
 
end
 
task :coverage do
  Rake::Task["coverage:all"].invoke
end
This creates the following rake tasks you might be interested in:
coverage:unit – runs coverage on tests in test/unit
coverage:func – runs coverage on tests in test/functional
coverage:all – runs all unit tests
coverage – synonym for coverage:all
Note that the */*_test.rb syntax may not work depending on your shell.
Of course, you need rcov, so I added the following to my Gemfile:
gem 'rcov'
Do a bundle install, and you should be able to run rake coverage. After running coverage, this script will automatically open your web browser to look at your coverage; It should look something like this, hopefully with more green bars than my just-getting-started project:

Happy Coding.

Tuesday 7 February 2012


Roodi [ Ruby Object Oriented Design Inferometer ]

Roodi stands for Ruby Object Oriented Design Inferometer. It parses your Ruby code and warns you about design issues you have based on the checks that is has configured.

Very easy to install and use with your code.

# gem install roodi

We can check one or more files using the default configuration that comes with roodi.

Check all ruby files in a rails app:
    roodi "rails_app/**/*.rb"

Check one controller and one model file in a rails app:
    roodi app/controller/sample_controller.rb app/models/sample.rb

Check one controller and all model files in a rails app:
    roodi app/controller/sample_controller.rb "app/models/*.rb"

Check all ruby files in a rails app with a custom configuration file:
    roodi -config=my_roodi_config.yml "rails_app/**/*.rb"

CUSTOM CONFIGURATION

To change the set of checks included, or to change the default values of the checks, you can provide your own config file. The config file is a YAML file that lists the checks to be included. Each check can optionally include a hash of options that are passed to the check to configure it. For example, the default config file looks like this:

    AssignmentInConditionalCheck:    { }
    CaseMissingElseCheck:            { }
    ClassLineCountCheck:             { line_count: 300 }
    ClassNameCheck:                  { pattern: !ruby/regexp /^[A-Z][a-zA-Z0-9]*$/ }
    CyclomaticComplexityBlockCheck:  { complexity: 4 }
    CyclomaticComplexityMethodCheck: { complexity: 8 }
    EmptyRescueBodyCheck:            { }
    ForLoopCheck:                    { }
    MethodLineCountCheck:            { line_count: 20 }
    MethodNameCheck:                 { pattern: !ruby/regexp /^[_a-z<>=\[\]|+-\/\*`]+[_a-z0-9_<>=~@\[\]]*[=!\?]?$/ }
    ModuleLineCountCheck:            { line_count: 300 }
    ModuleNameCheck:                 { pattern: !ruby/regexp /^[A-Z][a-zA-Z0-9]*$/ }
    ParameterNumberCheck:            { parameter_count: 5 }

PostgresSQL Commands for CentOS/Linux & pg_hba.conf configuration

Most of the time we can not install or use pgadmin. I tend to forget simple commands for administering the database. Hopefully this blog will help as reference when working with PostgreSQL

  • Login as "postgres" to start using database:
    # su - postgres
    
  • Create a new database:
    $ createdb mydb
    
  • Drop database:
    $ dropdb mydb
    
  • Access database:
    $ psql mydb
    
  • Get help:
    mydb=# \h
    
  • Quit:
    mydb=# \q
    
  • Read command from file:
    mydb=# \i input.sql
    
  • To dump a database:
    $ pg_dump mydb > db.out
    
  • To reload the database:
    $ psql -d database -f db.out
    
  • Dump all database:
    # su - postgres
    # pg_dumpall > /var/lib/pgsql/backups/dumpall.sql
    
  • Restore database:
    # su - postgres
    # psql -f /var/lib/pgsql/backups/dumpall.sql mydb
    
  • Show databases:
    #psql -l
    or
    mydb=# \l;
    
  • Show users:
    mydb=# SELECT * FROM "pg_user";
    
  • Show tables:
    mydb=# SELECT * FROM "pg_tables";
    
  • Set password:
    mydb=# UPDATE pg_shadow SET passwd = 'new_password' where usename = 'username';
    
  • Clean all databases (Should be done via a daily cron):
    $ vacuumdb --quiet --all

  • The pg_hba.conf file states who is allowed to connect to the database server and which authentication method must be used to establish the connection.This configuration is very useful when we try to connect database through pgadmin client.

    Default pg_hba.conf
    # TYPE  DATABASE    USER        CIDR-ADDRESS          METHOD
    
    # "local" is for Unix domain socket connections only
    local   all         all                               trust
    # IPv4 local connections:
    host    all         all         127.0.0.1/32          trust
    # IPv6 local connections:
    host    all         all         ::1/128               trust