iluvruby

There is an awesome gem called method_source (used internally in pry). Example:

Set.instance_method(:merge).source.display # => def merge(enum) if enum.instance_of?(self.class) @hash.update(enum.instance_variable_get(:@hash)) else do_with_enum(enum) { |o| add(o) } end self end

You can also see the comment for a given method!

Set.instance_method(:merge).comment.display # => # Merges the elements of the given enumerable object to the set and # returns self.

In case of a class (singleton) method, replace

instance_method

with just

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Have you ever been in a situation where you needed a method that does the following:

Converts nil to an empty array

Converts non-array variable n to [n]

Leaves array variable as is

The way to achieve this is using little known method Array()

In rspec tests in which you have more than one database connection, uncommitted changes made using one connection are visible only through that connection. Rspec starts a transaction before each test and rolls it back at the end so the database is in the clean state for the next test. This can be turned off, in which case you would have to make sure you clean up the database manually if needed. This change can be applied in the scope of a describe block like this: 

In ruby, symbols never get garbage collected. They stay in memory until the process exits. Get all the symbols in memory with the following command:

I have written a quick gem that allows you to copy and paste ruby objects across terminals. This gem has been created primarily to simplify the process of copying objects between different rails environments for people that spend a lot of time in the Rails console (like me). Some examples include long strings, or perhaps strings that are hard to copy due to the escaping involved. You might find it handy to copy the ActiveRecord object that has been misbehaving in production, or to copy an array of objects (to seed the test/development database).

Installation is straightforward: gem install copyrb

You will need to require the gem in both (or more) terminals with: require 'copyrb'

first terminal: copy my_object

second terminal: paste #=> my_object

If you use RubyGems, you can get that information in the following manner:

ActiveRecord will try to populate updated_at field every time a change on a given model has been persisted to the database. If for any reason (and you should ask yourself if your reasons are valid) you want to disable such functionality for a given class, this is how it's done:

MyModelClass.record_timestamps = false

If you change the attribute on a given ActiveRecord object and then try to access it in one of the hooks (even if it is before_save or before_update) the new value will be returned. However, sometimes you will need to access the old attribute values as well, whether for your application logic or cleanup purposes, and you might be tempted to fetch that value directly from the database, since the changes haven't been persisted yet.

Find out about specific gem dependencies by running:

gem dependency gem_name