How to 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.

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> 

You can granularly add libraries via the already mentioned

require 'active_support/core_ext/some_class/some_file'

There is also another level up where you can

require 'active_support/core_ext/some_class'

But, at the moment, this is unfortunately not available for Time, Date and DateTime.

A way around this is to require 'active_support/time' which will give you Time, Date and DateTime which would solve the OP was asking for without requiring everything.

---

My Rails patch, which adds active_support/core_ext/date and date_time, made it into Rails v4.0.0, so now you can require these individually. YAY!

In my case the following link worked:

https://bundler.io/blog/2019/01/04/an-update-on-the-bundler-2-release.html

$ cat Gemfile.lock | grep -A 1 "BUNDLED WITH"
BUNDLED WITH
   1.17.3

$ gem install bundler -v '1.17.3'

Does this work from the console? This is working for me:

$ sw_vers
ProductName:	Mac OS X
ProductVersion:	10.6.5
BuildVersion:	10H574

$ rails c
Loading development environment (Rails 3.0.3)
>> 1.week.ago
=> Sun, 14 Nov 2010 16:57:18 UTC +00:00

You can :
require 'active_support/core_ext'
or :
require 'active_support/all'