Rails 6 adds ActiveModel::Errors#of_kind?

Rails 6 added of_kind? on ActiveModel::Errors. It returns true if the ActiveModel::Errors object has provided a key and message associated with it. The default message is :invalid.

of_kind? is same as ActiveModel::Errors#added? but, it doesn't take extra options as a parameter.

Let's checkout how it works.

Rails 6.0.0.beta2

1>> class User < ApplicationRecord
2>>   validates :name, presence: true
3>> end
4
5>> user = User.new
6
7=> => #<User id: nil, name: nil, password: nil, created_at: nil, updated_at: nil>
8
9>> user.valid?
10
11=> false
12
13>> user.errors
14
15=> #<ActiveModel::Errors:0x00007fc462a1d140 @base=#<User id: nil, name: nil, password: nil, created_at: nil, updated_at: nil>, @messages={:name=>["can't be blank"]}, @details={:name=>[{:error=>:blank}]}>
16
17>> user.errors.of_kind?(:name)
18
19=> false
20
21>> user.errors.of_kind?(:name, :blank)
22
23=> true
24
25>> user.errors.of_kind?(:name, "can't be blank")
26
27=> true
28
29>> user.errors.of_kind?(:name, "is blank")
30
31=> false
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Here is the relevant pull request.