ruby on rails - How do I use Active Support core extensions?

I have Active Support 3.0.3 installed and Rails 3.0.3 with Ruby 1.8.7.

When I try to use 1.week.ago I get

NoMethodError: undefined method 'week' for 1:Fixnum
from (irb):2

The other core extensions seem to work. I tried it on a friend's computer (same install specs and legacy versions are on his) with the same results.

What gives?

All of this is in IRB.

Answer

Since using Rails should handle this automatically I'm going to assume you're trying to add Active Support to a non-Rails script.

Read "How to Load Core Extensions".

Active Support's methods got broken into smaller groups in Rails 3, so we don't end up loading a lot of unneeded stuff with a simple require 'activesupport'. Now we have to do things like require 'active_support/core_ext/object/blank'

If you don't care about granularity, you can choose to load bigger chunks. If you want everything in one big gulp use...

For 1.9.2:

rvm 1.9.2
irb -f
irb(main):001:0> require 'active_support/all'
=> true
irb(main):002:0> 1.week.ago
=> 2010-11-14 17:56:16 -0700
irb(main):003:0> 

For 1.8.7:

rvm 1.8.7
irb -f
irb(main):001:0> require 'rubygems'
=> true
irb(main):002:0> require 'active_support/all'
=> true
irb(main):003:0> 1.week.ago
=> Sun Nov 14 17:54:19 -0700 2010
irb(main):004:0>