Merge branch 'master' into update-todo-in-uiupdate-todo-in-ui

* master: (435 commits)
  Change occurrence of Sidekiq::Testing.inline!
  Fix order-dependent spec failure in appearance_spec.rb
  Put a failed example from appearance_spec in quarantine
  Cache PerformanceBar.allowed_user_ids list locally and in Redis
  Add Grafana to Admin > Monitoring menu when enabled
  Add changelog entry
  Add salesforce logo
  Move error_tracking_frontend specs to Jest
  Only save Peek session in Redis when Peek is enabled
  Migrate markdown header_spec.js to Jest
  Fix golint command in Go guide doc to be recursive
  Move images to their own dirs
  Gitlab -> GitLab
  Re-align CE and EE API docs
  Rename Release groups in issue_workflow.md
  Update api docs to finish aligning EE and CE docs
  Update locale.pot
  Update TODO: allow_collaboration column renaming
  Show upcoming status for releases
  Rebased and squashed commits
  ...

1 files changed, 36 insertions, 0 deletions

diff --git a/doc/development/reusing_abstractions.md b/doc/development/reusing_abstractions.md
index 01cedf734fb..59da02ed6fd 100644
--- a/doc/development/reusing_abstractions.md
+++ b/doc/development/reusing_abstractions.md
@@ -127,6 +127,42 @@ Everything in `lib/api`.
 
 Everything that resides in `app/services`.
 
+#### ServiceResponse
+
+Service classes usually have an `execute` method, which can return a
+`ServiceResponse`. You can use `ServiceResponse.success` and
+`ServiceResponse.error` to return a response in `execute` method.
+
+In a successful case:
+
+``` ruby
+response = ServiceResponse.success(message: 'Branch was deleted')
+
+response.success? # => true
+response.error? # => false
+response.status # => :success
+response.message # => 'Branch was deleted'
+```
+
+In a failed case:
+
+``` ruby
+response = ServiceResponse.error(message: 'Unsupported operation')
+
+response.success? # => false
+response.error? # => true
+response.status # => :error
+response.message # => 'Unsupported operation'
+```
+
+An additional payload can also be attached:
+
+``` ruby
+response = ServiceResponse.success(payload: { issue: issue })
+
+response.payload[:issue] # => issue
+```
+
 ### Finders
 
 Everything in `app/finders`, typically used for retrieving data from a database.