Add update validations to SnippetInputAction

app/models/snippet_input_action.rb

@@ -16,7 +16,8 @@ class SnippetInputAction
   validates :action, inclusion: { in: ACTIONS, message: "%{value} is not a valid action" }
   validates :previous_path, presence: true, if: :move_action?
   validates :file_path, presence: true
-  validates :content, presence: true, if: :create_action?
+  validates :content, presence: true, if: -> (action) { action.create_action? || action.update_action? }
+  validate :ensure_same_file_path_and_previous_path, if: :update_action?
 
   def initialize(action: nil, previous_path: nil, file_path: nil, content: nil)
     @action = action
@@ -41,4 +42,10 @@ class SnippetInputAction
 
     previous_path.presence || file_path
   end
+
+  def ensure_same_file_path_and_previous_path
+    return if previous_path == file_path
+
+    errors.add(:file_path, "can't be different from the previous_path attribute")
+  end
 end

changelogs/unreleased/fj-add-validations-snippet-input-action.yml

+---
+title: Add update validations to SnippetInputAction
+merge_request: 33379
+author:
+type: changed

spec/models/snippet_input_action_spec.rb

@@ -20,6 +20,8 @@ describe SnippetInputAction do
       'create' | 'foobar'  | ''       | 'foobar' | false
       'create' | nil       | 'foobar' | 'foobar' | false
       'create' | ''        | 'foobar' | 'foobar' | false
+      'update' | 'foobar'  | nil      | 'foobar' | false
+      'update' | 'other'   | 'foobar' | 'foobar' | false
     end
 
     with_them do