1 files changed, 77 insertions, 0 deletions
diff --git a/rubocop/cop/rspec/before_all_role_assignment.rb b/rubocop/cop/rspec/before_all_role_assignment.rb
new file mode 100644
index 00000000000..fc7fdf4208a
--- /dev/null
+++ b/rubocop/cop/rspec/before_all_role_assignment.rb
@@ -0,0 +1,77 @@
+# frozen_string_literal: true
+
+require 'rubocop-rspec'
+
+module Rubocop
+  module Cop
+    module RSpec
+      # Checks for let_it_be with before instead of before_all when using `add_*` methods
+      #
+      # @example
+      #
+      #   # bad
+      #   let_it_be(:project) { create(:project) }
+      #   let_it_be(:guest) { create(:user) }
+      #
+      #   before do
+      #     project.add_guest(guest)
+      #   end
+      #
+      #   # good
+      #   let_it_be(:project) { create(:project) }
+      #   let_it_be(:guest) { create(:user) }
+      #
+      #   before_all do
+      #     project.add_guest(guest)
+      #   end
+      class BeforeAllRoleAssignment < RuboCop::Cop::RSpec::Base
+        MSG = "Use `before_all` when used with `%{let_it_be}`."
+
+        ROLE_METHODS = %i[add_guest add_reporter add_developer add_maintainer add_owner add_role].to_set.freeze
+
+        RESTRICT_ON_SEND = ROLE_METHODS
+
+        # @!method matching_let_it_be(node)
+        def_node_matcher :matching_let_it_be, <<~PATTERN
+          (block (send nil? $/^let_it_be/ (sym %name)) ...)
+        PATTERN
+
+        # @!method before_block?(node)
+        def_node_matcher :before_block?, <<~PATTERN
+          (block (send nil? :before ...) ...)
+        PATTERN
+
+        def_node_matcher :object_calling_add_role_method, <<~PATTERN
+          (send (send nil? $_) %ROLE_METHODS ...)
+        PATTERN
+
+        def on_send(node)
+          object_calling_add_role = object_calling_add_role_method(node)
+          return unless object_calling_add_role
+
+          before_block = before_block_ancestor(node)
+          return unless before_block
+
+          each_block_node_in_ancestor(node) do |child_node|
+            matching_let_it_be(child_node, name: object_calling_add_role) do |let_it_be|
+              message = format(MSG, let_it_be: let_it_be)
+              add_offense(node, message: message)
+            end
+          end
+        end
+
+        private
+
+        def before_block_ancestor(node)
+          node.each_ancestor(:block).find { |block_node| before_block?(block_node) }
+        end
+
+        def each_block_node_in_ancestor(node, &block)
+          node.each_ancestor do |parent_node|
+            parent_node.each_child_node(:block, &block)
+          end
+        end
+      end
+    end
+  end
+end