Software Development

RCov Tips

2012-01-26T20:16:00.001-08:00

1. How to turn off rcov for specific sections in a file:
Start and end with :

#:nocov:

in your file.

2. How to exclude files from rcov:

In spec directory, edit rcov.opts

append our path of files to –exclude option. Eg: –exclude “helpers/*,app/sweepers/*”.

Reference

http://psixty.wordpress.com/2010/06/22/how-to-exclude-files-in-rcova-code-coverage-tool-in-ruby/

How to uninstall all gems in global rvm ?

2012-01-16T12:46:00.000-08:00

rvm use @global 
rvm gemset empty global

If you want to remove all gems for a particular gemset, replace global with your-gemset-name

gem "rake" is not installed

2012-01-16T12:08:00.000-08:00

Problem uninstalling rake? Run the following command:
rvm use @global && gem uninstall rake

How to disable acts_as_audited 2.0 rails plugin in Rails 3.1 and RSpec

2012-01-12T00:28:00.000-08:00

Create disable.rb under spec/support folder and call disable_auditing method on your modes. For example:
Account.disable_auditing
Cart.disable_auditing

Using Reek gem in Rails 3.1 projects

2012-01-09T15:22:00.001-08:00

1. gem install reek
2. reek lib/*.rb > myreport.txt

You can run reports for app/models/*.rb, app/controllers/*.rb and app/helpers/*.rb

rcov for Rails 3.1

2012-01-09T15:03:00.001-08:00

1. rake spec:rcov
2. open coverage/index.html
3. add coverage/* to your .gitignore file.
4. $ rake -T rcov
rake spec:clobber_rcov # Remove rcov products for rcov
rake spec:rcov # Run all specs in spec directory with RCov (excluding plugin specs)

Rails Best Practices

2012-01-09T14:53:00.000-08:00

1. gem install rails_best_practices
2. gem install ripper
3. From the root of the project run:
rails_best_practices -f html .
to generate the report.

You need to specify gem names as Strings. Use 'gem "test"' instead.

2011-12-25T15:22:00.000-08:00

This can happen due to syntax error in your Gemfile. Fix the sytax error by manually checking this file. If that does not work delete the lines that you added to result in this problem and copy / paste from a working copy of a Gemfile.

syntax error, unexpected keyword_end

2011-12-07T15:30:00.000-08:00

This happens because you have : <%= end %> instead of <% end %>

`test': unknown command 't' (ArgumentError)

2011-12-01T15:47:00.000-08:00

To write tests using Test::Unit new syntax :

test "truth" do
assert true
end

1. gem install test-unit
2. Code:

require 'rubygems'
gem 'test-unit'
require 'test/unit'

class ExampleTest < Test::Unit::TestCase
def test_truth
assert true
end

test "truth" do
assert true
end
end

3. Run: ruby example_test This will work on ruby-1.9.3-p0.

Reference: Test::Unit and MiniTest with different Ruby versions

Installing Ruby 1.9.3 using RVM on Mac OS Lion

2011-11-30T23:47:00.000-08:00

ERROR: The provided CC(gcc) is LLVM based, it is not yet fully supported by ruby and gems, please read `rvm requirements`.

1) Download Xcode 4.2.x via App Store.
2) Go to Applications folder and click Install Xcode
3) Download and install GCC from https://github.com/kennethreitz/osx-gcc-installer
4) In a new terminal run : export CC=gcc
and then run : rvm install 1.9.3
5) You may also want to upgrade ruby gems by running:
gem update --system

ActiveRecord::Relation, undefined method error

2011-11-02T10:52:00.000-07:00

If you are using the active record relationships to access columns, for instance:

Article has many comments
article.comments.where("spam = ?", false).order("created_at asc")

This returns ActiveRelation object that does not fire the query. Only when you loop through the results you can access the columns of comments objects. If you want to force the call to the database just append "all" to it like this:

article.comments.where("spam = ?", false).order("created_at asc").all

(local out of date) error in Git when working with branches

2011-10-24T11:43:00.000-07:00

1. git pull origin your-branch
2. git push origin your-branch

Step 1 brings your local branch to up-to date. Step 2 pushes your changes to the remote branch.

invalid date format in specification: gem ruby

2011-10-23T10:35:00.000-07:00

1) Upgraded ruby gems to 1.8.11 (gem update --system)
2) gem pristine --all

No luck.

Deleted all the gemspec that were causing problems: whenever-0.6.8.gemspec etc. Then bundle install made it work.

`build_extensions': ERROR: Failed to build gem native extension. (Gem::Installer::ExtensionBuildError)

2011-10-23T10:12:00.000-07:00

I was getting :
Installing eventmachine (0.12.10) with native extensions .rvm/rubies/ruby-1.8.7-p330/lib/ruby/site_ruby/1.8/rubygems/installer.rb:533:in `build_extensions': ERROR: Failed to build gem native extension. (Gem::Installer::ExtensionBuildError)

during the installation of scheduler_daemon on Mac OS Lion. Upgraded XCode via appstore (download from appstore and install) to resolve this issue.

Integrating Tweet Button in Rails App

2011-10-07T12:57:00.000-07:00

In Rails 3.0 app:

1) In Gemfile include:

gem 'tweet-button'

2) bundle install

3) In application_helper.rb include:

module ApplicationHelper
include TweetButton

... other methods...
end

4) In your partial:

<%= tweet_button(:via => "CreditCardLogic", :url => polymorphic_url(article), :text => "Check this out!") %>

To see this in action, check out my credit cards site.

Making a Branch the Master in GIT

2011-09-27T11:23:00.000-07:00

git checkout cat_killer
git merge -s ours master
git checkout master
git merge cat_killer
git push

cat_killer is the branch you want to make the master.

Stolen from Stackoverflow post.

no mongrel gem found in sdk rubymine

2011-09-20T11:31:00.000-07:00

Even if you are using RVM, Rubymine actually looks at the global installation for the gem. Install thin, mongrel etc on the global Ruby installation that is independent of any gemset.

How to start Thin server on a different port?

2011-09-20T10:30:00.001-07:00

thin start -p 80

require that is compatible with ruby 1.8.x and 1.9.x

2011-08-12T22:26:00.000-07:00

require File.expand_path(File.join(File.dirname(__FILE__), 'player'))

This makes : require 'player' work on both Ruby 1.8.x and 1.9.x

ImageMagick Installer

2011-08-07T15:34:00.000-07:00

Download the script from https://github.com/maddox/magick-installer/blob/master/magick-installer.sh and run it.

ImageScience on Snow Leopard

2011-08-07T13:53:00.000-07:00

1) Download and install MacPorts http://www.macports.org/install.php
2) sudo port install freeimage
3) env ARCHFLAGS="-arch x86_64" gem install RubyInline image_science

Reserved Words in Rails

2011-07-27T14:09:00.001-07:00

* ADDITIONAL_LOAD_PATHS
* ARGF
* ARGV
* ActionController
* ActionView
* ActiveRecord
* ArgumentError
* Array
* BasicSocket
* Benchmark
* Bignum
* Binding
* CGI
* CGIMethods
* CROSS_COMPILING
* Class
* ClassInheritableAttributes
* Comparable
* ConditionVariable
* Config
* Continuation
* DRb
* DRbIdConv
* DRbObject
* DRbUndumped
* Data
* Date
* DateTime
* Delegater
* Delegator
* Digest
* Dir
* ENV
* EOFError
* ERB
* Enumerable
* Errno
* Exception
* FALSE
* FalseClass
* Fcntl
* File
* FileList
* FileTask
* FileTest
* FileUtils
* Fixnum
* Float
* FloatDomainError
* GC
* Gem
* GetoptLong
* Hash
* IO
* IOError
* IPSocket
* IPsocket
* IndexError
* Inflector
* Integer
* Interrupt
* Kernel
* LN_SUPPORTED
* LoadError
* LocalJumpError
* Logger
* Marshal
* MatchData
* MatchingData
* Math
* Method
* Module
* Mutex
* Mysql
* MysqlError
* MysqlField
* MysqlRes
* NIL
* NameError
* NilClass
* NoMemoryError
* NoMethodError
* NoWrite
* NotImplementedError
* Numeric
* OPT_TABLE
* Object
* ObjectSpace
* Observable
* Observer
* PGError
* PGconn
* PGlarge
* PGresult
* PLATFORM
* PStore
* ParseDate
* Precision
* Proc
* Process
* Queue
* RAKEVERSION
* RELEASE_DATE
* RUBY
* RUBY_PLATFORM
* RUBY_RELEASE_DATE
* RUBY_VERSION
* Rack
* Rake
* RakeApp
* RakeFileUtils
* Range
* RangeError
* Rational
* Regexp
* RegexpError
* Request
* RuntimeError
* STDERR
* STDIN
* STDOUT
* ScanError
* ScriptError
* SecurityError
* Signal
* SignalException
* SimpleDelegater
* SimpleDelegator
* Singleton
* SizedQueue
* Socket
* SocketError
* StandardError
* String
* StringScanner
* Struct
* Symbol
* SyntaxError
* SystemCallError
* SystemExit
* SystemStackError
* TCPServer
* TCPSocket
* TCPserver
* TCPsocket
* TOPLEVEL_BINDING
* TRUE
* Task
* Text
* Thread
* ThreadError
* ThreadGroup
* Time
* Transaction
* TrueClass
* TypeError
* UDPSocket
* UDPsocket
* UNIXServer
* UNIXSocket
* UNIXserver
* UNIXsocket
* UnboundMethod
* Url
* VERSION
* Verbose
* YAML
* ZeroDivisionError

Other names that have been reported to cause trouble:

* accept
* callback – breaks validation if used as a model method.
* categorie
* action
* attributes – if you have a has_many called attributes, you can’t access to your object attributes anymore; only the associated objects
* application2
* @base_path – setting this variable name in a controller method seems to break the ablity to render a partial in the view. The view will render with no content and no errors will be generated .
* connection – there seems to be a connection class already
* database – (in mysql)
* dispatcher
* display1
* drive – fixtures will not autogenerate IDs in Rails 2.0.2
* errors
* format
* host – I had a text_field :host, :name that I saw problems with. (JR)
* key
* layout – If you have a model called Layout and in a controller have “scaffold :layout” it generates an exception. However, if you script/generate the scaffold for layout it works.
* load – When making an Ajax call to an action named load, the action’s code will be skipped (or otherwise rendered useless). This is made apparent by: a) @variables are not available in the view, b) calling render :layout => false still yields the layout.
* link – breaks migrations when used as a column name in combination with validation: ticket
* new, override to news if you want a news table
* notify – not a valid column name
* open – not a valid column name
* public
* quote ‘quote’ cannot be used as a column name
* render – cannot be used as an action name
* request
* records – a table named records seemed to cause duplicate entries to be found by find
* responses – scaffold borks with "undefined method ‘body=’ "
* save – ActiveRecord uses this to save the object.
* scope – do not use as an association name because ActiveRecord::Base.scope is called instead
* send
* session (session_controller or SessionController will not work)
* system – a table column named system causes problems when trying to generate scaffold
* template – a table named templates causes an error when you try to invoke the create method of the default controller
* test (however those work with ruby test/unit/axistest.rb_ and rake testunits_)
* timeout – an ActiveRecord attribute named timeout will clash with the global function “timeout” defined in Ruby’s timeout.rb
* to_s — naming a model instance method to_s resulted in ‘File not found’ for any view an object of this class (should have) appeared in (no matter which method called) and WebRick had to be restarted. I couldn’t drag the very cause into light, but in the traces ‘to_s’ gave me a hint. After renaming everything worked well again.
* type — or any of the other MagicFieldNames
* URI
* visits — a table column named visits causes problems when trying to query some_obj.visits.
* Observer — for a model name works in development environment but not in production.
singular names finishing in “s”: Axis → Axes, Access → Accesses, will break the pluralization in rake: Axi, Acces

Monitor cannot be used. It is a Ruby class that is related to threading.

List of Magic Field Names

* created_at
* created_on
* updated_at
* updated_on
* lock_version
* type
* id
* #{table_name}_count
* position
* parent_id
* lft
* rgt
* quote_value (is used for quoting)
* template

uninstalling rake 0.9.2

2011-07-27T11:11:00.000-07:00

gem uninstall rake
ERROR: While executing gem ... (Gem::InstallError)
cannot uninstall, check `gem list -d rake`

1) gem list -d rake

gives:

*** LOCAL GEMS ***

rake (0.9.2, 0.8.7)
Author: Jim Weirich
Rubyforge: http://rubyforge.org/projects/rake
Homepage: http://rake.rubyforge.org
Installed at (0.9.2): /Users/bparanj/.rvm/gems/ruby-1.9.2-p180@global
(0.8.7): /Users/bparanj/.rvm/gems/ruby-1.9.2-p180@global

2) rvm use @global && gem uninstall rake -v 0.9.2

uninstalls rake

Installing Ruby Debug

2011-07-15T18:37:00.000-07:00

1) From the root of the project run:
gem install ruby-debug19 -- --with-ruby-include="$rvm_path/src/$(rvm tools identifier)/"

2) Include in Gemfile

group :test, :development do
gem ‘ruby-debug19′, :require => ‘ruby-debug’
end

3) Create a .rdebugrc in your home directory

set autolist
set autoeval
set autoreload
set forcestep

4)
Specify how you would like Rails to report deprecation notices for your bugger environment, set
config.active_support.deprecation to :log, :notify or :stderr at config/environments/bugger.rb

5) require 'ruby-debug' in development.rb. Edit source where you want to debug to include :

debugger

6) Start server in debug mode:
rails s -d

References

http://pivotallabs.com/users/chad/blog/articles/366-ruby-debug-in-30-seconds-we-don-t-need-no-stinkin-gui-
http://bashdb.sourceforge.net/ruby-debug.html
http://railscasts.com/episodes/54-debugging-with-ruby-debug