Add RSpec/TopLevelDescribePath cop

The RSpec/FilePath cop checks that a spec file's path is correct, but
only if the file describes a constant. We want to check, for any file
with a top-level `describe`, whether the file path ends in
`_spec.rb`. We don't care what comes before that; just that it will be
executed by RSpec at all.

2 files changed, 36 insertions, 0 deletions

diff --git a/rubocop/cop/rspec/top_level_describe_path.rb b/rubocop/cop/rspec/top_level_describe_path.rb
new file mode 100644
index 00000000000..61796e23af0
--- /dev/null
+++ b/rubocop/cop/rspec/top_level_describe_path.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require 'rubocop/rspec/top_level_describe'
+
+module RuboCop
+  module Cop
+    module RSpec
+      class TopLevelDescribePath < RuboCop::Cop::Cop
+        include RuboCop::RSpec::TopLevelDescribe
+
+        MESSAGE = 'A file with a top-level `describe` must end in _spec.rb.'
+        SHARED_EXAMPLES = %i[shared_examples shared_examples_for].freeze
+
+        def on_top_level_describe(node, args)
+          return if acceptable_file_path?(processed_source.buffer.name)
+          return if shared_example?(node)
+
+          add_offense(node, message: MESSAGE)
+        end
+
+        private
+
+        def acceptable_file_path?(path)
+          File.fnmatch?('*_spec.rb', path) || File.fnmatch?('*/frontend/fixtures/*', path)
+        end
+
+        def shared_example?(node)
+          node.ancestors.any? do |node|
+            node.respond_to?(:method_name) && SHARED_EXAMPLES.include?(node.method_name)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/rubocop/rubocop.rb b/rubocop/rubocop.rb
index ba61a634d97..58a7ead6f13 100644
--- a/rubocop/rubocop.rb
+++ b/rubocop/rubocop.rb
@@ -32,6 +32,7 @@ require_relative 'cop/migration/update_large_table'
 require_relative 'cop/project_path_helper'
 require_relative 'cop/rspec/env_assignment'
 require_relative 'cop/rspec/factories_in_migration_specs'
+require_relative 'cop/rspec/top_level_describe_path'
 require_relative 'cop/qa/element_with_pattern'
 require_relative 'cop/sidekiq_options_queue'
 require_relative 'cop/destroy_all'