Array.uniq does not work in Prototype

When you run rake db:rollback and nothing happens, you are probably missing the latest migration file (or have not migrated yet).

$ rake db:rollback
$ 

If that happens to you, check your migration status.

$ rake db:migrate:status

...

Several Rails migration methods accept index: true as an option to create an index. In some cases (like #add_column), this option is silently discarded. Know what you are doing, or use #add_index instead.

Example

Consider the following ...

Be careful when stubbing out attributes on records that are defined by associations. Nothing is as it seems to be.

The associated record has its own universe of things; when delegating calls to it, you ca not stub methods on the associated record...

Today I needed to execute a ruby gem executable with sudo. But, surprisingly, bash would tell me command not found for the gem that ran lovely without sudo.

Gem bins are installed to /var/lib/gems/1.8/bin, which is not in sudo’s PATH....

Let's assume that we have a model Movie that registers a callback function when a new instance of Movie is created (Note: For the purpose of this card it is not important what that callback does or which type of callback it is).

This is how...

tl;dr: Do not use merge! for session hashes. Use update instead.

Outline

Let's assume you're modifying the Rails session. For simplicity, let's also assume your session is empty when you start (same effect when there is data):

# In o...

iPads will not trigger click events for all elements. You can fix that, but you don't want to know why.

Example: Capturing clicks on table rows (use case would be clicking the 1st link inside it for better UI). Consider this setup:

<table>

...

When updating WebMock, be prepared that your specs may send real requests into the depths of the internet unless you update Curb as well.\
WebMock will not complain about those ...

Turns out, Cucumber::MultilineArgument::DataTable#diff! caches some stuff. Code of the following form will not work as intended:

Then('some table should look like') do |expected_table|
  patiently do
    actual_table = calculate_actual_ta...

Association named 'variations' was not found; perhaps you misspelled it?

I just was hunting down a strange error with this model:

class Model
  placeholder = 'variations'
  
  has_many placeholder
  
  nested_scope :v...