Introduce a new FactoriesInMigrationSpecs cop

Signed-off-by: Rémy Coutable <remy@rymai.me>

1 files changed, 40 insertions, 0 deletions

diff --git a/rubocop/cop/rspec/factories_in_migration_specs.rb b/rubocop/cop/rspec/factories_in_migration_specs.rb
new file mode 100644
index 00000000000..0c5aa838a2c
--- /dev/null
+++ b/rubocop/cop/rspec/factories_in_migration_specs.rb
@@ -0,0 +1,40 @@
+require_relative '../../spec_helpers'
+
+module RuboCop
+  module Cop
+    module RSpec
+      # This cop checks for the usage of factories in migration specs
+      #
+      # @example
+      #
+      #   # bad
+      #   let(:user) { create(:user) }
+      #
+      #   # good
+      #   let(:users) { table(:users) }
+      #   let(:user) { users.create!(name: 'User 1', username: 'user1') }
+      class FactoriesInMigrationSpecs < RuboCop::Cop::Cop
+        include SpecHelpers
+
+        MESSAGE = "Don't use FactoryBot.%s in migration specs, use `table` instead.".freeze
+        FORBIDDEN_METHODS = %i[build build_list create create_list].freeze
+
+        def_node_search :forbidden_factory_usage?, <<~PATTERN
+          (send {(const nil? :FactoryBot) nil?} {#{FORBIDDEN_METHODS.map(&:inspect).join(' ')}} ...)
+        PATTERN
+
+        # Following is what node.children looks like on a match:
+        # - Without FactoryBot namespace: [nil, :build, s(:sym, :user)]
+        # - With FactoryBot namespace: [s(:const, nil, :FactoryBot), :build, s(:sym, :user)]
+        def on_send(node)
+          return unless in_migration_spec?(node)
+          return unless forbidden_factory_usage?(node)
+
+          method = node.children[1]
+
+          add_offense(node, location: :expression, message: MESSAGE % method)
+        end
+      end
+    end
+  end
+end