Add RSpec/Rails/AvoidSetupHook cop

CHANGELOG.md

@@ -5,6 +5,7 @@
 * Add missing documentation for `single_statement_only` style of `RSpec/ImplicitSubject` cop. ([@tejasbubane][])
 * Fix an exception in `DescribedClass` when accessing a constant on a variable in a spec that is nested in a namespace. ([@rrosenblum][])
 * Add new `RSpec/IdenticalEqualityAssertion` cop. ([@tejasbubane][])
+* Add `RSpec/Rails/AvoidSetupHook cop. ([@paydaylight][])
 
 ## 2.3.0 (2021-04-28)
 
@@ -618,3 +619,4 @@ Compatibility release so users can upgrade RuboCop to 0.51.0. No new features.
 [@stephannv]: https://github.com/stephannv
 [@Tietew]: https://github.com/Tietew
 [@rrosenblum]: https://github.com/rrosenblum
+[@paydaylight]: https://github.com/paydaylight

config/default.yml

@@ -759,6 +759,12 @@ RSpec/FactoryBot/FactoryClassName:
   VersionChanged: '2.0'
   StyleGuide: https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/FactoryBot/FactoryClassName
 
+RSpec/Rails/AvoidSetupHook:
+  Description: Checks that tests use RSpec `before` hook over Rails `setup` method.
+  Enabled: pending
+  VersionAdded: '2.4'
+  StyleGuide: https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/Rails/AvoidSetupHook
+
 RSpec/Rails/HttpStatus:
   Description: Enforces use of symbolic or numeric value to describe HTTP status.
   Enabled: true

docs/modules/ROOT/pages/cops.adoc

@@ -97,6 +97,7 @@
 
 === Department xref:cops_rspec/rails.adoc[RSpec/Rails]
 
+* xref:cops_rspec/rails.adoc#rspecrails/avoidsetuphook[RSpec/Rails/AvoidSetupHook]
 * xref:cops_rspec/rails.adoc#rspecrails/httpstatus[RSpec/Rails/HttpStatus]
 
 // END_COP_LIST

docs/modules/ROOT/pages/cops_rspec/rails.adoc

@@ -1,5 +1,38 @@
 = RSpec/Rails
 
+== RSpec/Rails/AvoidSetupHook
+
+|===
+| Enabled by default | Safe | Supports autocorrection | VersionAdded | VersionChanged
+
+| Pending
+| Yes
+| Yes
+| 2.4
+| -
+|===
+
+Checks that tests use RSpec `before` hook over Rails `setup` method.
+
+=== Examples
+
+[source,ruby]
+----
+# bad
+setup do
+  allow(foo).to receive(:bar)
+end
+
+# good
+before do
+  allow(foo).to receive(:bar)
+end
+----
+
+=== References
+
+* https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/Rails/AvoidSetupHook
+
 == RSpec/Rails/HttpStatus
 
 |===

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

@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module RSpec
+      module Rails
+        # Checks that tests use RSpec `before` hook over Rails `setup` method.
+        #
+        # @example
+        #
+        #   # bad
+        #   setup do
+        #     allow(foo).to receive(:bar)
+        #   end
+        #
+        #   # good
+        #   before do
+        #     allow(foo).to receive(:bar)
+        #   end
+        #
+        class AvoidSetupHook < Base
+          extend AutoCorrector
+
+          MSG = 'Use `before` instead of `setup`.'
+
+          # @!method setup_call(node)
+          def_node_matcher :setup_call, <<-PATTERN
+            (block
+              $(send nil? :setup)
+              (args) _)
+          PATTERN
+
+          def on_block(node)
+            setup_call(node) do |setup|
+              add_offense(node) do |corrector|
+                corrector.replace setup, 'before'
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/rubocop/cop/rspec_cops.rb

@@ -8,6 +8,7 @@
 require_relative 'rspec/factory_bot/create_list'
 require_relative 'rspec/factory_bot/factory_class_name'
 
+require_relative 'rspec/rails/avoid_setup_hook'
 begin
   require_relative 'rspec/rails/http_status'
 rescue LoadError

spec/rubocop/cop/rspec/rails/avoid_setup_hook_spec.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+RSpec.describe RuboCop::Cop::RSpec::Rails::AvoidSetupHook do
+  it 'registers an offense for `setup`' do
+    expect_offense(<<~RUBY)
+      setup do
+      ^^^^^^^^ Use `before` instead of `setup`.
+        allow(foo).to receive(:bar)
+      end
+    RUBY
+
+    expect_correction(<<~RUBY)
+      before do
+        allow(foo).to receive(:bar)
+      end
+    RUBY
+  end
+
+  it 'does not register an offense for `before`' do
+    expect_no_offenses(<<~RUBY)
+      before do
+        allow(foo).to receive(:bar)
+      end
+    RUBY
+  end
+
+  it 'does not register an offense for an unrelated `setup` call' do
+    expect_no_offenses(<<~RUBY)
+      navigation.setup do
+        direction 'to infinity!'
+      end
+    RUBY
+  end
+end