Add Cast Common Boolean-Like Values To Booleans as a Rails til

README.md

@@ -10,7 +10,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 For a steady stream of TILs from a variety of rocketeers, checkout
 [til.hashrocket.com](https://til.hashrocket.com/).
 
-_808 TILs and counting..._
+_809 TILs and counting..._
 
 ---
 
@@ -483,6 +483,7 @@ _808 TILs and counting..._
 - [Attribute Was](rails/attribute-was.md)
 - [Autosave False On ActiveRecord Associations](rails/autosave-false-on-activerecord-associations.md)
 - [Capybara Page Status Code](rails/capybara-page-status-code.md)
+- [Cast Common Boolean-Like Values To Booleans](rails/cast-common-boolean-like-values-to-booleans.md)
 - [Change The Nullability Of A Column](rails/change-the-nullability-of-a-column.md)
 - [Code Statistics For An Application](rails/code-statistics-for-an-application.md)
 - [Conditional Class Selectors in Haml](rails/conditional-class-selectors-in-haml.md)

rails/cast-common-boolean-like-values-to-booleans.md

@@ -0,0 +1,28 @@
+# Cast Common Boolean-Like Values To Booleans
+
+Sometimes you have to deal with values that are supposed to represent booleans,
+but they aren't actually boolean values (i.e. `"t"` instead of `true`). Rail's
+`ActiveModel` has a helper for casting these common boolean-like values to
+actual booleans.
+
+```ruby
+> ActiveModel::Type::Boolean.new.cast('f')
+=> false
+> ActiveModel::Type::Boolean.new.cast('t')
+=> true
+> ActiveModel::Type::Boolean.new.cast('true')
+=> true
+> ActiveModel::Type::Boolean.new.cast('FALSE')
+=> false
+> ActiveModel::Type::Boolean.new.cast(0)
+=> false
+> ActiveModel::Type::Boolean.new.cast(1)
+=> true
+> ActiveModel::Type::Boolean.new.cast(true)
+=> true
+> ActiveModel::Type::Boolean.new.cast(false)
+=> false
+```
+
+This cast method gives you a handy way to handle all thsoe different cases.
+This is available as of Rails 5+.