Predef

Shortcut for prepend-ing Module. Maybe useful for debugging.

Installation

Add this line to your application's Gemfile:

gem 'predef'

And then execute:

$ bundle

Or install it yourself as:

$ gem install predef

Usage

Example: Collect All Queries Executed in a Test

Given you're using some third-party database client library like this...

class HogeSQL::Connection
  def execute query
    # ...
  end

  # ...
end

Imagine you want to see all SELECT queries and the stacktrace when executed, without any change of HogeSQL::Connection.

require 'predef'

Predef.predef HogeSQL::Connection, :execute do|query|
  if query.include? 'SELECT'
    puts query
    pp caller
  end
  super # call the original query method.
end

# ... your app or some test code ...

Then you'd get...

SELECT * from your_apps_table WHERE ...
["/path/to/your_app/app/models/foo.rb:355:in `some_method_in_model'",
 "/path/to/your_app/app/controllers/foo_controller.rb:355:in `some_action_in_controller'",
 ...]

...

This is just a shortcut for:

module SomeWrapper
  def execute
    if query.include? 'SELECT'
      puts query
      pp caller
    end
    super # call the original execute method.
  end
end

HogeSQL::Connection.__send__(:prepend, SomeWrapper)

So you can more quickly inspect code you don't want to change directly!

More Ruby-ish Way

Or would you like using this way? Though it's a bit more verbose to prepend only one method.

using Predef::Refinements

HogeSQL::Connection.predef :execute do|query|
  # same here with the last example...
end

For more methods:

See and/or execute test/example.rb:

$ git clone git@github.com:igrep/predef.git
$ cd predef
$ bundle
$ bundle exec ruby test/example.rb

Contributing

1. Fork it ( https://github.com/igrep/predef/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request