Use setter for key instead AR callback

ref: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6763

app/models/key.rb

@@ -6,7 +6,7 @@ class Key < ActiveRecord::Base
 
   belongs_to :user
 
-  before_validation :strip_white_space, :generate_fingerprint
+  before_validation :generate_fingerprint
 
   validates :title, presence: true, length: { within: 0..255 }
   validates :key, presence: true, length: { within: 0..5000 }, format: { with: /\A(ssh|ecdsa)-.*\Z/ }
@@ -21,8 +21,9 @@ class Key < ActiveRecord::Base
   after_destroy :remove_from_shell
   after_destroy :post_destroy_hook
 
-  def strip_white_space
-    self.key = key.strip unless key.blank?
+  def key=(value)
+    value.strip! unless value.blank?
+    write_attribute(:key, value)
   end
 
   def publishable_key

changelogs/unreleased/setter-for-key.yml

+---
+title: Use setter for key instead AR callback
+merge_request: 7488
+author: Semyon Pupkov

spec/models/key_spec.rb

@@ -82,4 +82,14 @@ describe Key, models: true do
       @key.destroy
     end
   end
+
+  describe '#key=' do
+    let(:valid_key) do
+      "ssh-rsa AAAAB3NzaC1yc2EAAAABJQAAAIEAiPWx6WM4lhHNedGfBpPJNPpZ7yKu+dnn1SJejgt4596k6YjzGGphH2TUxwKzxcKDKKezwkpfnxPkSMkuEspGRt/aZZ9wa++Oi7Qkr8prgHc4soW6NUlfDzpvZK2H5E7eQaSeP3SAwGmQKUFHCddNaP0L+hM7zhFNzjFvpaMgJw0= dummy@gitlab.com"
+    end
+
+    it 'strips white spaces' do
+      expect(described_class.new(key: " #{valid_key} ").key).to eq(valid_key)
+    end
+  end
 end