Persist Rails or IRB Console Command History After Exit
Create, or edit your ~/.irbrc file to include:
require 'irb/ext/eval_history' # was 'irb/ext/save-history' for versions prior to Ruby 3.3
IRB.conf[:SAVE_HISTORY] = 2000
IRB.conf[:HISTORY_FILE] = "#{ENV['HOME']}/.irb-history"
Related cards:
Ruby: How to measure code execution time in an IRB or Rails console
Modern IRB has time measurement built in.
measure # Enable
measure :off # Disable
Custom
Should your version of IRB not offer this feature, you can measure manually. Paste this method into your console:
def time(&block) puts Bench...
Solving "TypeError (nil can't be coerced into Integer)" in the Rails console / IRB
On the Rails console, assigning an object to a variable can lead to this strange error (without stacktrace):
irb > recipient = Recipient.find(123)
Traceback (most recent call last):
TypeError (nil can't be coerced into Integer)
irb > recipi...
Use non-ASCII characters on IRB and Rails consoles with RVM and Mac OS X
If you are using RVM on a Mac and cannot enter 8+ bit characters on an IRB or Rails console, you are missing the readline package. You will need to re-install your Ruby to fix this:
rvm remove ree
rvm package install readline
rvm in...
How to fix: irb / rails console randomly crashing
If your irb or rails console keeps randomly crashing and you can't figure out why then you can try to disable multi-line autocomplete.
Make your Rails console (and irb) output better readable
Pour color on your Rails console with awesome_print. Turn confusing long strings into formatted output. Have objects and classes laid out clearly whenever you need it.
Put `gem 'awesome_print', :g...
Start Rails console or server with debugger
When you require the Ruby debugger to be available from your Rails console (e.g. you want to inspect a method's magic), you need to enable it explicitly:
script/console --debugger
If you cannot access local variables etc, [see this card](/mak...
Rails console tricks
Also see the list of IRB commands.
Switching the context
Changes the "default receiver" of expressions. Can be used to simulate a "debugger situation" where you are "inside" an object. This is espe...
Your Rails sandbox console
Just found out about a great feature in Rails that seems to be around since Rails 2. Start a console with the --sandbox (or -s) parameter:
rails console --sandbox
All changes you make to the database will be rolled back on ...
How to fix "undefined method `name' for Array" error when running bundled commands on Ruby 1.8.7 + Rails 2.3
On recent/fresh installations of Ruby 1.8.7 you may encounter this error why calling any bundled binary (or just bundle exec):
/home/arne/.rvm/gems/ruby-1.8.7-p374@global/gems/rubygems-bundler-1.4.2/lib/rubygems-bundler/noexec.rb:75:in ...
console-for opens a Rails console remotely on a Capistrano deployment target
We're adding a script console-for to open a remote Rails console with one command. Also have a look at shell-for, which this script is rel...