How to list all validators in a Rails model

Rails models have a validators class method. It comes in handy to review validation rules distributed over multiple classes and modules in a larger codebase.

Official example:

class Person
  include ActiveModel::Validations

  validates_with MyValidator
  validates_with OtherValidator, on: :create
  validates_with StrictValidator, strict: true
end

Person.validators
# => [
#      #<MyValidator:0x007fbff403e808 @options={}>,
#      #<OtherValidator:0x007fbff403d930 @options={on: :create}>,
#      #<StrictValidator:0x007fbff3204a30 @options={strict:true}>
#    ]

There is also #validators_on(:attribute) to fetch attribute-specific validators.

References:

rails

Somewhat related: