implement repeated block description/body cops

Author: lazycoder9

CHANGELOG.md

@@ -5,6 +5,8 @@
 * Fix `RSpec/InstanceVariable` detection inside custom matchers. ([@pirj][])
 * Fix `RSpec/ScatteredSetup` to distinguish hooks with different metadata. ([@pirj][])
 * Add autocorrect support for `RSpec/ExpectActual` cop. ([@dduugg][], [@pirj][])
+* Add `RSpec/RepeatedBlockBody` copy. ([@lazycoder9][])
+* Add `RSpec/RepeatedBlockDescription` copy. ([@lazycoder9][])
 
 ## 1.37.1 (2019-12-16)
 
@@ -477,3 +479,4 @@ Compatibility release so users can upgrade RuboCop to 0.51.0. No new features.
 [@jfragoulis]: https://github.com/jfragoulis
 [@ybiquitous]: https://github.com/ybiquitous
 [@dduugg]: https://github.com/dduugg
+[@lazycoder9]: https://github.com/lazycoder9

config/default.yml

@@ -384,6 +384,16 @@ RSpec/ReceiveNever:
   Description: Prefer `not_to receive(...)` over `receive(...).never`.
   StyleGuide: https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/ReceiveNever
 
+RSpec/RepeatedBlockBody:
+  Enabled: true
+  Description: Check for repeated describe and context block body.
+  StyleGuide: https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/RepeatedBlockBody
+
+RSpec/RepeatedBlockDescription:
+  Enabled: true
+  Description: Check for repeated describe and context block descriptions.
+  StyleGuide: https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/RepeatedBlockDescription
+
 RSpec/RepeatedDescription:
   Enabled: true
   Description: Check for repeated description strings in example groups.

lib/rubocop/cop/rspec/repeated_block_body.rb

@@ -0,0 +1,79 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module RSpec
+      # Check for repeated describe and context block body.
+      #
+      # @example
+      #
+      #    # bad
+      #    describe 'cool feature x' do
+      #      it { cool_predicate }
+      #    end
+      #
+      #    describe 'cool feature y' do
+      #      it { cool_predicate }
+      #    end
+      #
+      #    # good
+      #    describe 'cool feature' do
+      #      it { cool_predicate }
+      #    end
+      #
+      #    describe 'another cool feature' do
+      #      it { another_predicate }
+      #    end
+      #
+      #    # bad
+      #    context 'when case x' do
+      #      it { cool_predicate }
+      #    end
+      #
+      #    context 'when case y' do
+      #      it { cool_predicate }
+      #    end
+      #
+      #    # good
+      #    context 'when case x' do
+      #      it { cool_predicate }
+      #    end
+      #
+      #    context 'when case y' do
+      #      it { another_predicate }
+      #    end
+      #
+      class RepeatedBlockBody < Cop
+        MSG = "Don't repeat block body"
+
+        def_node_matcher :several_blocks?, <<-PATTERN
+          (begin (block (send nil? {:context :describe} ...) ...)+ )
+        PATTERN
+
+        def_node_matcher :extract_metadata, '(block (send _ _ _ $...) ...)'
+        def_node_matcher :extract_body, '(block send args $...)'
+
+        def on_begin(node)
+          return unless several_blocks?(node)
+
+          repeated_block_bodies(node).each { |child| add_offense(child) }
+        end
+
+        private
+
+        def repeated_block_bodies(node)
+          grouped_blocks = node
+            .children
+            .group_by do |child|
+            [child.method_name, extract_metadata(child), extract_body(child)]
+          end
+
+          grouped_blocks
+            .select { |_, group| group.size > 1 }
+            .values
+            .flatten
+        end
+      end
+    end
+  end
+end

lib/rubocop/cop/rspec/repeated_block_description.rb

@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module RSpec
+      # Check for repeated describe and context block descriptions.
+      #
+      # @example
+      #
+      #    # bad
+      #    describe 'cool feature' do
+      #      # example group
+      #    end
+      #
+      #    describe 'cool feature' do
+      #      # example group
+      #    end
+      #
+      #    # bad
+      #    context 'when case x' do
+      #      # example group
+      #    end
+      #
+      #    describe 'when case x' do
+      #      # example group
+      #    end
+      #
+      #    # good
+      #    describe 'cool feature' do
+      #      # example group
+      #    end
+      #
+      #    describe 'another cool feature' do
+      #      # example group
+      #    end
+      #
+      #    # good
+      #    context 'when case x' do
+      #      # example group
+      #    end
+      #
+      #    describe 'when another case' do
+      #      # example group
+      #    end
+      #
+      class RepeatedBlockDescription < Cop
+        MSG = "Don't repeat block descriptions"
+
+        def_node_matcher :several_blocks?, <<-PATTERN
+          (begin (block (send nil? {:context :describe} ...) ...)+ )
+        PATTERN
+
+        def_node_matcher :extract_doc_string, '(block (send _ _ $str ...) ...)'
+
+        def on_begin(node)
+          return unless several_blocks?(node)
+
+          repeated_block_descriptions(node).each { |child| add_offense(child) }
+        end
+
+        private
+
+        def repeated_block_descriptions(node)
+          node
+            .children
+            .group_by { |child| [child.method_name, extract_doc_string(child)] }
+            .select { |block, group| block && group.size > 1 }
+            .values
+            .flatten
+        end
+      end
+    end
+  end
+end

lib/rubocop/cop/rspec_cops.rb

@@ -72,6 +72,8 @@
 require_relative 'rspec/predicate_matcher'
 require_relative 'rspec/receive_counts'
 require_relative 'rspec/receive_never'
+require_relative 'rspec/repeated_block_body'
+require_relative 'rspec/repeated_block_description'
 require_relative 'rspec/repeated_description'
 require_relative 'rspec/repeated_example'
 require_relative 'rspec/return_from_stub'

manual/cops.md

@@ -71,6 +71,8 @@
 * [RSpec/PredicateMatcher](cops_rspec.md#rspecpredicatematcher)
 * [RSpec/ReceiveCounts](cops_rspec.md#rspecreceivecounts)
 * [RSpec/ReceiveNever](cops_rspec.md#rspecreceivenever)
+* [RSpec/RepeatedBlockBody](cops_rspec.md#rspecrepeatedblockbody)
+* [RSpec/RepeatedBlockDescription](cops_rspec.md#rspecrepeatedblockdescription)
 * [RSpec/RepeatedDescription](cops_rspec.md#rspecrepeateddescription)
 * [RSpec/RepeatedExample](cops_rspec.md#rspecrepeatedexample)
 * [RSpec/ReturnFromStub](cops_rspec.md#rspecreturnfromstub)

manual/cops_rspec.md

@@ -2490,6 +2490,110 @@ expect(foo).not_to receive(:bar)
 
 * [https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/ReceiveNever](https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/ReceiveNever)
 
+## RSpec/RepeatedBlockBody
+
+Enabled by default | Supports autocorrection
+--- | ---
+Enabled | No
+
+Check for repeated describe and context block body.
+
+### Examples
+
+```ruby
+# bad
+describe 'cool feature x' do
+  it { cool_predicate }
+end
+
+describe 'cool feature y' do
+  it { cool_predicate }
+end
+
+# bad
+context 'when case x' do
+  it { cool_predicate }
+end
+
+describe 'when case y' do
+  it { cool_predicate }
+end
+
+# good
+describe 'cool feature' do
+  it { cool_predicate }
+end
+
+describe 'another cool feature' do
+  it { another_predicate }
+end
+
+# good
+context 'when case x' do
+  it { cool_predicate }
+end
+
+describe 'when another case' do
+  it { another_predicate }
+end
+```
+
+### References
+
+* [https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/RepeatedBlockBody](https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/RepeatedBlockBody)
+
+## RSpec/RepeatedBlockDescription
+
+Enabled by default | Supports autocorrection
+--- | ---
+Enabled | No
+
+Check for repeated describe and context block descriptions.
+
+### Examples
+
+```ruby
+# bad
+describe 'cool feature' do
+  # example group
+end
+
+describe 'cool feature' do
+  # example group
+end
+
+# bad
+context 'when case x' do
+  # example group
+end
+
+describe 'when case x' do
+  # example group
+end
+
+# good
+describe 'cool feature' do
+  # example group
+end
+
+describe 'another cool feature' do
+  # example group
+end
+
+# good
+context 'when case x' do
+  # example group
+end
+
+describe 'when another case' do
+  # example group
+end
+```
+
+### References
+
+* [https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/RepeatedBlockDescription](https://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/RepeatedBlockDescription)
+
 ## RSpec/RepeatedDescription
 
 Enabled by default | Supports autocorrection

spec/rubocop/cop/rspec/repeated_block_body_spec.rb

@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+RSpec.describe RuboCop::Cop::RSpec::RepeatedBlockBody do
+  subject(:cop) { described_class.new }
+
+  it 'registers an offense for repeated describe body' do
+    expect_offense(<<-RUBY)
+      describe 'doing x' do
+      ^^^^^^^^^^^^^^^^^^^^^ Don't repeat block body
+        it { cool_predicate_method }
+      end
+
+      describe 'doing y' do
+      ^^^^^^^^^^^^^^^^^^^^^ Don't repeat block body
+        it { cool_predicate_method }
+      end
+    RUBY
+  end
+
+  it 'registers an offense for repeated context body' do
+    expect_offense(<<-RUBY)
+      context 'when awesome case' do
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Don't repeat block body
+        it { cool_predicate_method }
+      end
+
+      context 'when another awesome case' do
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Don't repeat block body
+        it { cool_predicate_method }
+      end
+    RUBY
+  end
+
+  it 'does not register offense for different block body implementation' do
+    expect_no_offenses(<<-RUBY)
+      context 'when awesome case' do
+        it { cool_predicate_method }
+      end
+
+      context 'when another awesome case' do
+        it { another_predicate_method }
+      end
+    RUBY
+  end
+
+  it 'does not register offense if rspec tag magic is involved' do
+    expect_no_offenses(<<-RUBY)
+      describe 'doing x' do
+        it { cool_predicate_method }
+      end
+
+      describe 'doing x', :request do
+        it { cool_predicate_method }
+      end
+    RUBY
+  end
+end