[Fix #1016] Add Rails/RedundantAll cop

changelog/fix_add_rails_redundant_all_cop.md

@@ -0,0 +1 @@
+* [#1016](https://github.com/rubocop/rubocop-rails/issues/1016): Add `Rails/RedundantAll` cop. ([@masato-bkn][])

config/default.yml

@@ -775,6 +775,12 @@ Rails/ReadWriteAttribute:
   Include:
     - app/models/**/*.rb
 
+Rails/RedundantAll:
+  Description: Detect redundant `all` used as a receiver for Active Record query methods.
+  Enabled: true
+  Safe: false
+  VersionAdded: "<<next>>"
+
 Rails/RedundantAllowNil:
   Description: >-
                  Finds redundant use of `allow_nil` when `allow_blank` is set to

lib/rubocop/cop/rails/redundant_all.rb

@@ -0,0 +1,143 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Rails
+      # Detect redundant `all` used as a receiver for Active Record query methods.
+      #
+      # @safety
+      #   This cop is unsafe if the receiver object is not an Active Record object.
+      #
+      # @example
+      #   # bad
+      #   User.all.order(:created_at)
+      #   User.all.find(id)
+      #   User.all.where(id: ids)
+      #
+      #   # good
+      #   User.order(:created_at)
+      #   User.find(id)
+      #   User.where(id: ids)
+      class RedundantAll < Base
+        include ActiveRecordHelper
+        extend AutoCorrector
+
+        MSG = 'Redundant `all` detected'
+
+        RESTRICT_ON_SEND = [:all].freeze
+
+        # Defined methods in `ActiveRecord::Querying::QUERYING_METHODS` on activerecord 7.0.5.
+        QUERYING_METHODS = %i[
+          and
+          annotate
+          any?
+          average
+          calculate
+          count
+          create_or_find_by
+          create_or_find_by!
+          create_with
+          delete_all
+          delete_by
+          destroy_all
+          destroy_by
+          distinct
+          eager_load
+          except
+          excluding
+          exists?
+          extending
+          extract_associated
+          fifth
+          fifth!
+          find
+          find_by
+          find_by!
+          find_each
+          find_in_batches
+          find_or_create_by
+          find_or_create_by!
+          find_or_initialize_by
+          find_sole_by
+          first
+          first!
+          first_or_create
+          first_or_create!
+          first_or_initialize
+          forty_two
+          forty_two!
+          fourth
+          fourth!
+          from
+          group
+          having
+          ids
+          in_batches
+          in_order_of
+          includes
+          invert_where
+          joins
+          last
+          last!
+          left_joins
+          left_outer_joins
+          limit
+          lock
+          many?
+          maximum
+          merge
+          minimum
+          none
+          none?
+          offset
+          one?
+          only
+          optimizer_hints
+          or
+          order
+          pick
+          pluck
+          preload
+          readonly
+          references
+          reorder
+          reselect
+          rewhere
+          second
+          second!
+          second_to_last
+          second_to_last!
+          select
+          sole
+          strict_loading
+          sum
+          take
+          take!
+          third
+          third!
+          third_to_last
+          third_to_last!
+          touch_all
+          unscope
+          update_all
+          where
+          without
+        ].freeze
+
+        def on_send(node)
+          query_node = node.parent
+
+          return unless query_node&.send_type?
+          return unless QUERYING_METHODS.include?(query_node.method_name)
+          return if node.receiver.nil? && !inherit_active_record_base?(node)
+
+          all_range = node.loc.selector
+          add_offense(all_range) do |collector|
+            collector.remove(all_range)
+            collector.remove(query_node.loc.dot)
+          end
+        end
+      end
+    end
+  end
+end

lib/rubocop/cop/rails_cops.rb

@@ -87,6 +87,7 @@
 require_relative 'rails/present'
 require_relative 'rails/rake_environment'
 require_relative 'rails/read_write_attribute'
+require_relative 'rails/redundant_all'
 require_relative 'rails/redundant_allow_nil'
 require_relative 'rails/redundant_foreign_key'
 require_relative 'rails/redundant_presence_validation_on_belongs_to'

spec/rubocop/cop/rails/redundant_all_spec.rb

@@ -0,0 +1,192 @@
+# frozen_string_literal: true
+
+RSpec.describe RuboCop::Cop::Rails::RedundantAll, :config do
+  sources = [
+    'and(User.where(age: 30))',
+    'annotate("selecting id")',
+    'any?',
+    'average(:age)',
+    'calculate(:average, :age)',
+    'count',
+    'create_or_find_by(name: name)',
+    'create_or_find_by!(name: name)',
+    'create_with(name: name)',
+    'delete_all',
+    'delete_by(id: id)',
+    'destroy_all',
+    'destroy_by(id: id)',
+    'distinct',
+    'eager_load(:posts)',
+    'except(:order)',
+    'excluding(user)',
+    'exists?',
+    'extending(Pagination)',
+    'extract_associated(:posts)',
+    'fifth',
+    'fifth!',
+    'find(id)',
+    'find_by(name: name)',
+    'find_by!(name: name)',
+    'find_each(&:do_something)',
+    'find_in_batches(&:do_something)',
+    'find_or_create_by(name: name)',
+    'find_or_create_by!(name: name)',
+    'find_or_initialize_by(name: name)',
+    'find_sole_by(name: name)',
+    'first',
+    'first!',
+    'first_or_create(name: name)',
+    'first_or_create!(name: name)',
+    'first_or_initialize(name: name)',
+    'forty_two',
+    'forty_two!',
+    'fourth',
+    'fourth!',
+    'from("users")',
+    'group(:age)',
+    'having("AVG(age) > 30")',
+    'ids',
+    'in_batches(&:do_something)',
+    'in_order_of(:id, ids)',
+    'includes(:posts)',
+    'invert_where',
+    'joins(:posts)',
+    'last',
+    'last!',
+    'left_joins(:posts)',
+    'left_outer_joins(:posts)',
+    'limit(n)',
+    'lock',
+    'many?',
+    'maximum(:age)',
+    'merge(users)',
+    'minimum(:age)',
+    'none',
+    'none?',
+    'offset(n)',
+    'one?',
+    'only(:order)',
+    'optimizer_hints("SeqScan(users)", "Parallel(users 8)")',
+    'or(User.where(age: 30))',
+    'order(:created_at)',
+    'pick(:id)',
+    'pluck(:age)',
+    'preload(:posts)',
+    'readonly',
+    'references(:posts)',
+    'reorder(:created_at)',
+    'reselect(:age)',
+    'rewhere(id: ids)',
+    'second',
+    'second!',
+    'second_to_last',
+    'second_to_last!',
+    'select(:age)',
+    'sole',
+    'strict_loading',
+    'sum(:age)',
+    'take(n)',
+    'take!',
+    'third',
+    'third!',
+    'third_to_last',
+    'third_to_last!',
+    'touch_all',
+    'unscope(:order)',
+    'update_all(name: name)',
+    'where(id: ids)',
+    'without(user)'
+  ]
+
+  describe '::QUERYING_METHODS' do
+    it 'contains all of the querying methods' do
+      methods = sources.map { |s| s.split('(')[0].to_sym }
+      expect(described_class::QUERYING_METHODS).to eq(methods)
+    end
+  end
+
+  context 'with receiver' do
+    sources.each do |source|
+      it "registers an offense and corrects when `all.#{source}`" do
+        expect_offense(<<~RUBY)
+          User.all.#{source}
+               ^^^ Redundant `all` detected
+        RUBY
+
+        expect_correction(<<~RUBY)
+          User.#{source}
+        RUBY
+      end
+    end
+
+    it 'does not register an offense when not using any method' do
+      expect_no_offenses(<<~RUBY)
+        User.all
+      RUBY
+    end
+
+    it 'does not register an offense when not using defined methods in ::QUERYING_METHODS' do
+      expect_no_offenses(<<~RUBY)
+        User.all.map(&:do_something)
+      RUBY
+    end
+  end
+
+  context 'with no receiver' do
+    it 'does not register an offense when not inheriting any class' do
+      expect_no_offenses(<<~RUBY)
+        class User
+          def do_something
+            all.where(id: ids)
+          end
+        end
+      RUBY
+    end
+
+    it 'does not register an offense when not inheriting `ApplicationRecord`' do
+      expect_no_offenses(<<~RUBY)
+        class User < Foo
+          def do_something
+            all.where(id: ids)
+          end
+        end
+      RUBY
+    end
+
+    it 'registers an offense when inheriting `ApplicationRecord`' do
+      expect_offense(<<~RUBY)
+        class User < ApplicationRecord
+          scope :admins, -> { all.where(admin: true) }
+                              ^^^ Redundant `all` detected
+        end
+      RUBY
+    end
+
+    it 'registers an offense when inheriting `::ApplicationRecord`' do
+      expect_offense(<<~RUBY)
+        class User < ::ApplicationRecord
+          scope :admins, -> { all.where(admin: true) }
+                              ^^^ Redundant `all` detected
+        end
+      RUBY
+    end
+
+    it 'registers an offense when inheriting `ActiveRecord::Base`' do
+      expect_offense(<<~RUBY)
+        class User < ActiveRecord::Base
+          scope :admins, -> { all.where(admin: true) }
+                              ^^^ Redundant `all` detected
+        end
+      RUBY
+    end
+
+    it 'registers an offense when inheriting `::ActiveRecord::Base`' do
+      expect_offense(<<~RUBY)
+        class User < ::ActiveRecord::Base
+          scope :admins, -> { all.where(admin: true) }
+                              ^^^ Redundant `all` detected
+        end
+      RUBY
+    end
+  end
+end