[Fix rubocop#12309] Add new Style/ZeroAritySuper cop

changelog/new_add_new_style_zero_arity_super_cop.md

@@ -0,0 +1 @@
+* [#12309](https://github.com/rubocop/rubocop/issues/12309): Add new `Style/ZeroAritySuper` cop. ([@earlopain][])

config/default.yml

@@ -5722,6 +5722,11 @@ Style/YodaExpression:
     - '|'
     - '^'
 
+Style/ZeroAritySuper:
+  Description: 'Call `super` without arguments and parentheses when the signature is identical.'
+  Enabled: false
+  VersionAdded: '<<next>>'
+
 Style/ZeroLengthPredicate:
   Description: 'Use #empty? when testing for objects of length 0.'
   Enabled: true

lib/rubocop.rb

@@ -711,6 +711,7 @@
 require_relative 'rubocop/cop/style/yaml_file_read'
 require_relative 'rubocop/cop/style/yoda_condition'
 require_relative 'rubocop/cop/style/yoda_expression'
+require_relative 'rubocop/cop/style/zero_arity_super'
 require_relative 'rubocop/cop/style/zero_length_predicate'
 
 require_relative 'rubocop/cop/security/compound_hash'

lib/rubocop/cop/style/zero_arity_super.rb

@@ -0,0 +1,144 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Style
+      # Checks for redundant argument forwarding when calling super
+      # with arguments identical to the method definition.
+      #
+      # @example
+      #   # bad
+      #   def method(*args, **kwargs)
+      #     super(*args, **kwargs)
+      #   end
+      #
+      #   # good - implicitly passing all arguments
+      #   def method(*args, **kwargs)
+      #     super
+      #   end
+      #
+      #   # good - forwarding a subset of the arguments
+      #   def method(*args, **kwargs)
+      #     super(*args)
+      #   end
+      #
+      #   # good - forwarding no arguments
+      #   def method(*args, **kwargs)
+      #     super()
+      #   end
+      class ZeroAritySuper < Base
+        extend AutoCorrector
+
+        DEF_TYPES = %i[def defs].freeze
+
+        MSG = 'Call `super` without arguments and parentheses when the signature is identical.'
+
+        def on_super(super_node)
+          def_node = super_node.ancestors.find do |node|
+            # You can't implicitly call super when dynamically defining methods
+            break if define_method?(node)
+
+            break node if DEF_TYPES.include?(node.type)
+          end
+          return unless def_node
+          return unless arguments_identical?(def_node.arguments.argument_list, super_node.arguments)
+
+          add_offense(super_node) { |corrector| corrector.replace(super_node, 'super') }
+        end
+
+        private
+
+        # rubocop:disable Metrics/CyclomaticComplexity
+        # rubocop:disable Metrics/PerceivedComplexity
+        def arguments_identical?(def_args, super_args)
+          super_args = preprocess_super_args(super_args)
+          return false if def_args.size != super_args.size
+
+          def_args.zip(super_args).each do |def_arg, super_arg|
+            next if positional_arg_same?(def_arg, super_arg)
+            next if positional_rest_arg_same(def_arg, super_arg)
+            next if keyword_arg_same?(def_arg, super_arg)
+            next if keyword_rest_arg_same?(def_arg, super_arg)
+            next if block_arg_same?(def_arg, super_arg)
+            next if forward_arg_same?(def_arg, super_arg)
+
+            return false
+          end
+          true
+        end
+        # rubocop:enable Metrics/CyclomaticComplexity
+        # rubocop:enable Metrics/PerceivedComplexity
+
+        def positional_arg_same?(def_arg, super_arg)
+          return false unless def_arg.arg_type? || def_arg.optarg_type?
+          return false unless super_arg.lvar_type?
+
+          def_arg.name == super_arg.children.first
+        end
+
+        def positional_rest_arg_same(def_arg, super_arg)
+          return false unless def_arg.restarg_type?
+          # anon forwarding
+          return true if def_arg.name.nil? && super_arg.forwarded_restarg_type?
+          return false unless super_arg.splat_type?
+          return false unless (lvar_node = super_arg.children.first).lvar_type?
+
+          def_arg.name == lvar_node.children.first
+        end
+
+        def keyword_arg_same?(def_arg, super_arg)
+          return false unless def_arg.kwarg_type? || def_arg.kwoptarg_type?
+          return false unless (pair_node = super_arg).pair_type?
+          return false unless (sym_node = pair_node.key).sym_type?
+          return false unless (lvar_node = pair_node.value).lvar_type?
+          return false unless sym_node.value == lvar_node.children.first
+
+          def_arg.name == sym_node.value
+        end
+
+        def keyword_rest_arg_same?(def_arg, super_arg)
+          return false unless def_arg.kwrestarg_type?
+          # anon forwarding
+          return true if def_arg.name.nil? && super_arg.forwarded_kwrestarg_type?
+          return false unless super_arg.kwsplat_type?
+          return false unless (lvar_node = super_arg.children.first).lvar_type?
+
+          def_arg.name == lvar_node.children.first
+        end
+
+        def block_arg_same?(def_arg, super_arg)
+          return false unless def_arg.blockarg_type? && super_arg.block_pass_type?
+          # anon forwarding
+          return true if (block_pass_child = super_arg.children.first).nil? && def_arg.name.nil?
+
+          def_arg.name == block_pass_child.children.first
+        end
+
+        def forward_arg_same?(def_arg, super_arg)
+          return false unless def_arg.forward_arg_type? && super_arg.forwarded_args_type?
+
+          true
+        end
+
+        def define_method?(node)
+          return false unless node.block_type?
+
+          child = node.child_nodes.first
+          return false unless child.send_type?
+
+          child.method?(:define_method) || child.method?(:define_singleton_method)
+        end
+
+        def preprocess_super_args(super_args)
+          super_args.map do |node|
+            if node.hash_type? && !node.braces?
+              node.children
+            else
+              node
+            end
+          end.flatten
+        end
+      end
+    end
+  end
+end

spec/rubocop/cop/style/zero_arity_super_spec.rb

@@ -0,0 +1,220 @@
+# frozen_string_literal: true
+
+RSpec.describe RuboCop::Cop::Style::ZeroAritySuper, :config do
+  shared_examples 'offense' do |description, args, forwarded_args = args|
+    it "registers and corrects an offense when using def`#{description} (#{args}) => (#{forwarded_args})`" do
+      expect_offense(<<~RUBY, forwarded_args: forwarded_args)
+        def method(#{args})
+          super(#{forwarded_args})
+          ^^^^^^^{forwarded_args}^ Call `super` without arguments and parentheses when the signature is identical.
+        end
+      RUBY
+
+      expect_correction(<<~RUBY)
+        def method(#{args})
+          super
+        end
+      RUBY
+    end
+
+    it "registers and corrects an offense when using defs`#{description} (#{args}) => (#{forwarded_args})`" do
+      expect_offense(<<~RUBY, forwarded_args: forwarded_args)
+        def self.method(#{args})
+          super(#{forwarded_args})
+          ^^^^^^^{forwarded_args}^ Call `super` without arguments and parentheses when the signature is identical.
+        end
+      RUBY
+
+      expect_correction(<<~RUBY)
+        def self.method(#{args})
+          super
+        end
+      RUBY
+    end
+  end
+
+  shared_examples 'no offense' do |description, args, forwarded_args = args|
+    it "registers no offense when using def `#{description} (#{args}) => (#{forwarded_args})`" do
+      expect_no_offenses(<<~RUBY)
+        def method(#{args})
+          super(#{forwarded_args})
+        end
+      RUBY
+    end
+
+    it "registers no offense when using defs `#{description} (#{args}) => (#{forwarded_args})`" do
+      expect_no_offenses(<<~RUBY)
+        def self.method(#{args})
+          super(#{forwarded_args})
+        end
+      RUBY
+    end
+  end
+
+  it_behaves_like 'offense', 'no arguments', ''
+  it_behaves_like 'offense', 'single positional argument', 'a'
+  it_behaves_like 'offense', 'multiple positional arguments', 'a, b'
+  it_behaves_like 'offense', 'multiple positional arguments with default', 'a, b, c = 1', 'a, b, c'
+  it_behaves_like 'offense', 'positional/keyword argument', 'a, b:', 'a, b: b'
+  it_behaves_like 'offense', 'positional/keyword argument with default', 'a, b: 1', 'a, b: b'
+  it_behaves_like 'offense', 'positional/keyword argument both with default', 'a = 1, b: 2', 'a, b: b'
+  it_behaves_like 'offense', 'named block argument', '&blk'
+  it_behaves_like 'offense', 'positional splat arguments', '*args'
+  it_behaves_like 'offense', 'keyword splat arguments', '**kwargs'
+  it_behaves_like 'offense', 'positional/keyword splat arguments', '*args, **kwargs'
+  it_behaves_like 'offense', 'positionalkeyword splat arguments with block', '*args, **kwargs, &blk'
+  it_behaves_like 'offense', 'keyword arguments mixed with forwarding', 'a:, **kwargs', 'a: a, **kwargs'
+  it_behaves_like 'offense', 'tripple dot forwarding', '...'
+  it_behaves_like 'offense', 'tripple dot forwarding with extra arg', 'a, ...'
+
+  it_behaves_like 'no offense', 'different amount of positional arguments', 'a, b', 'a'
+  it_behaves_like 'no offense', 'positional arguments in different order', 'a, b', 'b, a'
+  it_behaves_like 'no offense', 'keyword arguments in different order', 'a:, b:', 'b: b, a: a'
+  it_behaves_like 'no offense', 'positional/keyword argument mixing', 'a, b', 'a, b: b'
+  it_behaves_like 'no offense', 'positional/keyword argument mixing reversed', 'a, b:', 'a, b'
+  it_behaves_like 'no offense', 'block argument with different name', '&blk', '&other_blk'
+  it_behaves_like 'no offense', 'keyword arguments and hash', 'a:', '{ a: a }'
+  it_behaves_like 'no offense', 'keyword arguments with send node', 'a:, b:', 'a: a, b: c'
+  it_behaves_like 'no offense', 'tripple dot forwarding with extra param', '...', 'a, ...'
+  it_behaves_like 'no offense', 'tripple dot forwarding with different param', 'a, ...', 'b, ...'
+  it_behaves_like 'no offense', 'keyword forwarding with extra keyword', 'a, **kwargs', 'a: a, **kwargs'
+
+  context 'Ruby >= 3.1', :ruby31 do
+    it_behaves_like 'offense', 'hash value omission', 'a:'
+    it_behaves_like 'offense', 'anon block forwarding', '&'
+  end
+
+  context 'Ruby >= 3.2', :ruby32 do
+    it_behaves_like 'offense', 'anon positional forwarding', '*'
+    it_behaves_like 'offense', 'anon keyword forwarding', '**'
+
+    it_behaves_like 'no offense', 'mixed anon forwarding', '*, **', '*'
+    it_behaves_like 'no offense', 'mixed anon forwarding', '*, **', '**'
+  end
+
+  it 'registers no offense when explicitly passing no arguments' do
+    expect_no_offenses(<<~RUBY)
+      def foo(a)
+        super()
+      end
+    RUBY
+  end
+
+  it 'registers an offense when passign along no arguments' do
+    expect_offense(<<~RUBY)
+      def foo
+        super()
+        ^^^^^^^ Call `super` without arguments and parentheses when the signature is identical.
+      end
+    RUBY
+  end
+
+  it 'registers an offense for nested declarations' do
+    expect_offense(<<~RUBY)
+      def foo(a)
+        def bar(b:)
+          super(b: b)
+          ^^^^^^^^^^^ Call `super` without arguments and parentheses when the signature is identical.
+        end
+        super(a)
+        ^^^^^^^^ Call `super` without arguments and parentheses when the signature is identical.
+      end
+    RUBY
+  end
+
+  it 'registers no offense when calling super in a dsl method' do
+    expect_no_offenses(<<~RUBY)
+      describe 'example' do
+        subject { super() }
+      end
+    RUBY
+  end
+
+  context 'when calling super with an extra block argument' do
+    it 'registers no offense when calling super with no arguments' do
+      expect_no_offenses(<<~RUBY)
+        def test
+          super { x }
+        end
+      RUBY
+    end
+
+    it 'registers no offense when calling super with implicit positional arguments' do
+      expect_no_offenses(<<~RUBY)
+        def test(a)
+          super { x }
+        end
+      RUBY
+    end
+
+    it 'registers no offense for a method with block when calling super with positional argument' do
+      expect_no_offenses(<<~RUBY)
+        def test(a, &blk)
+          super(a) { x }
+        end
+      RUBY
+    end
+  end
+
+  context 'scope changes' do
+    it 'registers no offense when the scope changes because of a class definition with block' do
+      expect_no_offenses(<<~RUBY)
+        def foo(a)
+          Class.new do
+            def foo(a, b)
+              super(a)
+            end
+          end
+        end
+      RUBY
+    end
+  end
+
+  it 'registers an offense when the scope changes because of a block' do
+    expect_offense(<<~RUBY)
+      def foo(a)
+        bar do
+          super(a)
+          ^^^^^^^^ Call `super` without arguments and parentheses when the signature is identical.
+        end
+      end
+    RUBY
+  end
+
+  it 'registers an offense when the scope changes because of a numblock' do
+    expect_offense(<<~RUBY)
+      def foo(a)
+        bar do
+          baz(_1)
+          super(a)
+          ^^^^^^^^ Call `super` without arguments and parentheses when the signature is identical.
+        end
+      end
+    RUBY
+  end
+
+  it 'registers no offense when the scope changes because of sclass' do
+    expect_no_offenses(<<~RUBY)
+      def foo(a)
+        class << self
+          def foo(b)
+            super(a)
+          end
+        end
+      end
+    RUBY
+  end
+
+  it 'registers no offense when calling super in define_singleton_method' do
+    expect_no_offenses(<<~RUBY)
+      def test(a)
+        define_singleton_method(:test2) do |a|
+          super(a)
+        end
+        b.define_singleton_method(:test2) do |a|
+          super(a)
+        end
+      end
+    RUBY
+  end
+end