rules:
- id: rails-no-render-after-save
  mode: taint
  pattern-sources:
  - patterns:
    - pattern: $T
    - pattern-inside: |
        $T.save
        ...
  pattern-sinks:
  - patterns:
    - pattern-inside: |
        render $T
  message: Found a call to `render $T` after calling `$T.save`. Do not call `render`
    after calling `save` on an ActiveRecord object. Reloading the page will cause
    the state-changing operation to be repeated which may cause undesirable side
    effects. Use `redirect_to` instead.
  languages:
  - ruby
  severity: WARNING
  fix: redirect_to $T
  metadata:
    references:
    - https://guides.rubyonrails.org/getting_started.html#creating-a-new-article
    category: correctness
    technology:
    - rails
    - ruby
    - activerecord