Je montre ici une simple mesure de sécurité concernant les expressions régulières de validation.

1. Vos RegExps sont fausses !
Simon COURTOIS - @happynoff

2. ^...$

3. ^...$
class User < ActiveRecord::Base
attr_accessible :email
validates :email,
presence: true,
uniqueness: true,
format: {
with: /^[A-Z0-9._%+-]+@[A-Z0-9.-]+.[A-Z]{2,4}$/i
}
end
http://www.regular-expressions.info/email.html

4. ^...$
toto@exemple.fr ✔
totoexemple.fr ✗
hello
toto@exemple.fr ✔
hello

5. ^...$

6. ˆ...$
http://ruby-doc.org/core-1.9.3/Regexp.html
Anchors
^ - Matches beginning of line
$ - Matches end of line

7. ^...$
➜ hello
➜ totoexemple.fr
➜ hello

8. A...Z
http://ruby-doc.org/core-1.9.3/Regexp.html
Anchors
^ - Matches beginning of line
$ - Matches end of line
A - Matches beginning of string
Z - Matches end of string

9. A...Z
class User < ActiveRecord::Base
attr_accessible :email
validates :email,
presence: true,
uniqueness: true,
format: {
with: /^[A-Z0-9._%+-]+@[A-Z0-9.-]+.[A-Z]{2,4}$/i
}
end

10. A...Z
class User < ActiveRecord::Base
attr_accessible :email
validates :email,
presence: true,
uniqueness: true,
format: {
with: /A[A-Z0-9._%+-]+@[A-Z0-9.-]+.[A-Z]{2,4}Z/i
}
end

11. A...Z
toto@exemple.fr ✔
totoexemple.fr ✗
hello
totoexemple.fr ✗
hello

12. A...Z

13. Merci !
Simon COURTOIS - @happynoff