diff options
Diffstat (limited to 'rubocop')
-rw-r--r-- | rubocop/cop/module_with_instance_variables.rb | 73 | ||||
-rw-r--r-- | rubocop/rubocop.rb | 3 |
2 files changed, 76 insertions, 0 deletions
diff --git a/rubocop/cop/module_with_instance_variables.rb b/rubocop/cop/module_with_instance_variables.rb new file mode 100644 index 00000000000..95e612b58e8 --- /dev/null +++ b/rubocop/cop/module_with_instance_variables.rb @@ -0,0 +1,73 @@ +module RuboCop + module Cop + class ModuleWithInstanceVariables < RuboCop::Cop::Cop + MSG = <<~EOL.freeze + Do not use instance variables in a module. Please read this + for the rationale behind it: + + doc/development/module_with_instance_variables.md + + If you think the use for this is fine, please just add: + # rubocop:disable Cop/ModuleWithInstanceVariables + EOL + + def on_module(node) + return if + rails_helper?(node) || rails_mailer?(node) || spec_helper?(node) + + check_method_definition(node) + + # Not sure why some module would have an extra begin wrapping around + node.each_child_node(:begin) do |begin_node| + check_method_definition(begin_node) + end + end + + private + + # We ignore Rails helpers right now because it's hard to workaround it + def rails_helper?(node) + node.source_range.source_buffer.name =~ + %r{app/helpers/\w+_helper.rb\z} + end + + # We ignore Rails mailers right now because it's hard to workaround it + def rails_mailer?(node) + node.source_range.source_buffer.name =~ + %r{app/mailers/emails/} + end + + # We ignore spec helpers because it usually doesn't matter + def spec_helper?(node) + node.source_range.source_buffer.name =~ + %r{spec/support/|features/steps/} + end + + def check_method_definition(node) + node.each_child_node(:def) do |definition| + # We allow this pattern: + # def f + # @f ||= true + # end + if only_ivar_or_assignment?(definition) + # We don't allow if any other ivar is used + definition.each_descendant(:ivar) do |offense| + add_offense(offense, :expression) + end + else + definition.each_descendant(:ivar, :ivasgn) do |offense| + add_offense(offense, :expression) + end + end + end + end + + def only_ivar_or_assignment?(definition) + node = definition.child_nodes.last + + definition.child_nodes.size == 2 && + node.or_asgn_type? && node.child_nodes.first.ivasgn_type? + end + end + end +end diff --git a/rubocop/rubocop.rb b/rubocop/rubocop.rb index 4ebbe010e90..7db56349cd7 100644 --- a/rubocop/rubocop.rb +++ b/rubocop/rubocop.rb @@ -5,6 +5,9 @@ require_relative 'cop/gem_fetcher' require_relative 'cop/in_batches' require_relative 'cop/polymorphic_associations' require_relative 'cop/project_path_helper' +require_relative 'cop/active_record_dependent' +require_relative 'cop/in_batches' +require_relative 'cop/module_with_instance_variables' require_relative 'cop/redirect_with_status' require_relative 'cop/migration/add_column' require_relative 'cop/migration/add_column_with_default_to_large_table' |