Add RSpec/Rails/InferredSpecType cop

.rubocop.yml

@@ -136,3 +136,5 @@ RSpec/Rails/AvoidSetupHook:
   Enabled: true
 RSpec/Rails/HaveHttpStatus:
   Enabled: true
+RSpec/Rails/InferredSpecType:
+  Enabled: true

CHANGELOG.md

@@ -9,6 +9,7 @@
 * Add `AllowedPatterns` configuration option to `RSpec/NoExpectationExample`.  ([@ydah][])
 * Improve `RSpec/NoExpectationExample` cop to ignore examples skipped or pending via metatada.  ([@pirj][])
 * Add `RSpec/FactoryBot/ConsistentParenthesesStyle` cop. ([@Liberatys][])
+* Add `RSpec/Rails/InferredSpecType` cop. ([@r7kamura][])
 
 ## 2.13.2 (2022-09-23)
 

config/default.yml

@@ -981,6 +981,29 @@ RSpec/Rails/HaveHttpStatus:
   VersionAdded: '2.12'
   Reference: https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/Rails/HaveHttpStatus
 
+RSpec/Rails/InferredSpecType:
+  Description: Identifies redundant spec type.
+  Enabled: pending
+  Safe: false
+  VersionAdded: '2.14'
+  Reference: https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/Rails/InferredSpecType
+  Inferences:
+    channels: channel
+    controllers: controller
+    features: feature
+    generator: generator
+    helpers: helper
+    jobs: job
+    mailboxes: mailbox
+    mailers: mailer
+    models: model
+    requests: request
+    integration: request
+    api: request
+    routing: routing
+    system: system
+    views: view
+
 RSpec/Rails/HttpStatus:
   Description: Enforces use of symbolic or numeric value to describe HTTP status.
   Enabled: true

docs/modules/ROOT/pages/cops.adoc

@@ -113,5 +113,6 @@
 * xref:cops_rspec_rails.adoc#rspecrails/avoidsetuphook[RSpec/Rails/AvoidSetupHook]
 * xref:cops_rspec_rails.adoc#rspecrails/havehttpstatus[RSpec/Rails/HaveHttpStatus]
 * xref:cops_rspec_rails.adoc#rspecrails/httpstatus[RSpec/Rails/HttpStatus]
+* xref:cops_rspec_rails.adoc#rspecrails/inferredspectype[RSpec/Rails/InferredSpecType]
 
 // END_COP_LIST

docs/modules/ROOT/pages/cops_rspec_rails.adoc

@@ -121,3 +121,86 @@ it { is_expected.to have_http_status :error }
 === References
 
 * https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/Rails/HttpStatus
+
+== RSpec/Rails/InferredSpecType
+
+|===
+| Enabled by default | Safe | Supports autocorrection | Version Added | Version Changed
+
+| Pending
+| No
+| Yes (Unsafe)
+| 2.14
+| -
+|===
+
+Identifies redundant spec type.
+
+After setting up rspec-rails, you will have enabled
+`config.infer_spec_type_from_file_location!` by default in
+spec/rails_helper.rb. This cop works in conjunction with this config.
+If you disable this config, disable this cop as well.
+
+=== Safety
+
+This cop is marked as unsafe because
+`config.infer_spec_type_from_file_location!` may not be enabled.
+
+=== Examples
+
+[source,ruby]
+----
+# bad
+# spec/models/user_spec.rb
+RSpec.describe User, type: :model do
+end
+
+# good
+# spec/models/user_spec.rb
+RSpec.describe User do
+end
+
+# good
+# spec/models/user_spec.rb
+RSpec.describe User, type: :common do
+end
+----
+
+==== `Inferences` configuration
+
+[source,ruby]
+----
+# .rubocop.yml
+# RSpec/InferredSpecType:
+#   Inferences:
+#     services: service
+
+# bad
+# spec/services/user_spec.rb
+RSpec.describe User, type: :service do
+end
+
+# good
+# spec/services/user_spec.rb
+RSpec.describe User do
+end
+
+# good
+# spec/services/user_spec.rb
+RSpec.describe User, type: :common do
+end
+----
+
+=== Configurable attributes
+
+|===
+| Name | Default value | Configurable values
+
+| Inferences
+| `{"channels"=>"channel", "controllers"=>"controller", "features"=>"feature", "generator"=>"generator", "helpers"=>"helper", "jobs"=>"job", "mailboxes"=>"mailbox", "mailers"=>"mailer", "models"=>"model", "requests"=>"request", "integration"=>"request", "api"=>"request", "routing"=>"routing", "system"=>"system", "views"=>"view"}`
+| 
+|===
+
+=== References
+
+* https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/Rails/InferredSpecType

lib/rubocop/cop/rspec/rails/inferred_spec_type.rb

@@ -0,0 +1,135 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module RSpec
+      module Rails
+        # Identifies redundant spec type.
+        #
+        # After setting up rspec-rails, you will have enabled
+        # `config.infer_spec_type_from_file_location!` by default in
+        # spec/rails_helper.rb. This cop works in conjunction with this config.
+        # If you disable this config, disable this cop as well.
+        #
+        # @safety
+        #   This cop is marked as unsafe because
+        #   `config.infer_spec_type_from_file_location!` may not be enabled.
+        #
+        # @example
+        #   # bad
+        #   # spec/models/user_spec.rb
+        #   RSpec.describe User, type: :model do
+        #   end
+        #
+        #   # good
+        #   # spec/models/user_spec.rb
+        #   RSpec.describe User do
+        #   end
+        #
+        #   # good
+        #   # spec/models/user_spec.rb
+        #   RSpec.describe User, type: :common do
+        #   end
+        #
+        # @example `Inferences` configuration
+        #   # .rubocop.yml
+        #   # RSpec/InferredSpecType:
+        #   #   Inferences:
+        #   #     services: service
+        #
+        #   # bad
+        #   # spec/services/user_spec.rb
+        #   RSpec.describe User, type: :service do
+        #   end
+        #
+        #   # good
+        #   # spec/services/user_spec.rb
+        #   RSpec.describe User do
+        #   end
+        #
+        #   # good
+        #   # spec/services/user_spec.rb
+        #   RSpec.describe User, type: :common do
+        #   end
+        class InferredSpecType < Base
+          extend AutoCorrector
+
+          MSG = 'Remove redundant spec type.'
+
+          # @param [RuboCop::AST::BlockNode] node
+          def on_block(node)
+            return unless example_group?(node)
+
+            pair_node = describe_with_type(node)
+            return unless pair_node
+            return unless inferred_type?(pair_node)
+
+            removable_node = detect_removable_node(pair_node)
+            add_offense(removable_node) do |corrector|
+              autocorrect(corrector, removable_node)
+            end
+          end
+          alias on_numblock on_block
+
+          private
+
+          # @!method describe_with_type(node)
+          #   @param [RuboCop::AST::BlockNode] node
+          #   @return [RuboCop::AST::PairNode, nil]
+          def_node_matcher :describe_with_type, <<~PATTERN
+            (block
+              (send #rspec? #ExampleGroups.all
+                ...
+                (hash <$(pair (sym :type) sym) ...>)
+              )
+              ...
+            )
+          PATTERN
+
+          # @param [RuboCop::AST::Corrector] corrector
+          # @param [RuboCop::AST::Node] node
+          def autocorrect(corrector, node)
+            corrector.remove(
+              node.location.expression.with(
+                begin_pos: node.left_sibling.location.expression.end_pos
+              )
+            )
+          end
+
+          # @param [RuboCop::AST::PairNode] node
+          # @return [RuboCop::AST::Node]
+          def detect_removable_node(node)
+            if node.parent.pairs.size == 1
+              node.parent
+            else
+              node
+            end
+          end
+
+          # @return [String]
+          def file_path
+            processed_source.file_path
+          end
+
+          # @param [RuboCop::AST::PairNode] node
+          # @return [Boolean]
+          def inferred_type?(node)
+            inferred_type_from_file_path.inspect == node.value.source
+          end
+
+          # @return [Symbol, nil]
+          def inferred_type_from_file_path
+            inferences.find do |prefix, type|
+              break type.to_sym if file_path.include?("spec/#{prefix}/")
+            end
+          end
+
+          # @return [Hash]
+          def inferences
+            cop_config['Inferences'] || {}
+          end
+        end
+      end
+    end
+  end
+end

lib/rubocop/cop/rspec_cops.rb

@@ -20,6 +20,7 @@
 rescue LoadError
   # Rails/HttpStatus cannot be loaded if rack/utils is unavailable.
 end
+require_relative 'rspec/rails/inferred_spec_type'
 
 require_relative 'rspec/align_left_let_brace'
 require_relative 'rspec/align_right_let_brace'