6 files changed, 148 insertions, 1 deletions
diff --git a/rubocop/cop/active_record_dependent.rb b/rubocop/cop/active_record_dependent.rb
new file mode 100644
index 00000000000..8d15f150885
--- /dev/null
+++ b/rubocop/cop/active_record_dependent.rb
@@ -0,0 +1,26 @@
+require_relative '../model_helpers'
+
+module RuboCop
+  module Cop
+    # Cop that prevents the use of `dependent: ...` in ActiveRecord models.
+    class ActiveRecordDependent < RuboCop::Cop::Cop
+      include ModelHelpers
+
+      MSG = 'Do not use `dependent: to remove associated data, ' \
+        'use foreign keys with cascading deletes instead'.freeze
+
+      METHOD_NAMES = [:has_many, :has_one, :belongs_to].freeze
+
+      def on_send(node)
+        return unless in_model?(node)
+        return unless METHOD_NAMES.include?(node.children[1])
+
+        node.children.last.each_node(:pair) do |pair|
+          key_name = pair.children[0].children[0]
+
+          add_offense(pair, :expression) if key_name == :dependent
+        end
+      end
+    end
+  end
+end
diff --git a/rubocop/cop/activerecord_serialize.rb b/rubocop/cop/active_record_serialize.rb
index 9bdcc3b4c34..204caf37f8b 100644
--- a/rubocop/cop/activerecord_serialize.rb
+++ b/rubocop/cop/active_record_serialize.rb
@@ -3,7 +3,7 @@ require_relative '../model_helpers'
 module RuboCop
   module Cop
     # Cop that prevents the use of `serialize` in ActiveRecord models.
-    class ActiverecordSerialize < RuboCop::Cop::Cop
+    class ActiveRecordSerialize < RuboCop::Cop::Cop
       include ModelHelpers
 
       MSG = 'Do not store serialized data in the database, use separate columns and/or tables instead'.freeze
diff --git a/rubocop/cop/in_batches.rb b/rubocop/cop/in_batches.rb
new file mode 100644
index 00000000000..c0240187e66
--- /dev/null
+++ b/rubocop/cop/in_batches.rb
@@ -0,0 +1,16 @@
+require_relative '../model_helpers'
+
+module RuboCop
+  module Cop
+    # Cop that prevents the use of `in_batches`
+    class InBatches < RuboCop::Cop::Cop
+      MSG = 'Do not use `in_batches`, use `each_batch` from the EachBatch module instead'.freeze
+
+      def on_send(node)
+        return unless node.children[1] == :in_batches
+
+        add_offense(node, :selector)
+      end
+    end
+  end
+end
diff --git a/rubocop/cop/migration/add_column_with_default_to_large_table.rb b/rubocop/cop/migration/add_column_with_default_to_large_table.rb
index 2372e6b60ea..87788b0d9c2 100644
--- a/rubocop/cop/migration/add_column_with_default_to_large_table.rb
+++ b/rubocop/cop/migration/add_column_with_default_to_large_table.rb
@@ -20,8 +20,11 @@ module RuboCop
           'necessary'.freeze
 
         LARGE_TABLES = %i[
+          ci_builds
           events
           issues
+          merge_request_diff_files
+          merge_request_diffs
           merge_requests
           namespaces
           notes
diff --git a/rubocop/cop/migration/hash_index.rb b/rubocop/cop/migration/hash_index.rb
new file mode 100644
index 00000000000..2cc59691d84
--- /dev/null
+++ b/rubocop/cop/migration/hash_index.rb
@@ -0,0 +1,51 @@
+require 'set'
+require_relative '../../migration_helpers'
+
+module RuboCop
+  module Cop
+    module Migration
+      # Cop that prevents the use of hash indexes in database migrations
+      class HashIndex < RuboCop::Cop::Cop
+        include MigrationHelpers
+
+        MSG = 'hash indexes should be avoided at all costs since they are not ' \
+          'recorded in the PostgreSQL WAL, you should use a btree index instead'.freeze
+
+        NAMES = Set.new([:add_index, :index, :add_concurrent_index]).freeze
+
+        def on_send(node)
+          return unless in_migration?(node)
+
+          name = node.children[1]
+
+          return unless NAMES.include?(name)
+
+          opts = node.children.last
+
+          return unless opts && opts.type == :hash
+
+          opts.each_node(:pair) do |pair|
+            next unless hash_key_type(pair) == :sym &&
+                hash_key_name(pair) == :using
+
+            if hash_key_value(pair).to_s == 'hash'
+              add_offense(pair, :expression)
+            end
+          end
+        end
+
+        def hash_key_type(pair)
+          pair.children[0].type
+        end
+
+        def hash_key_name(pair)
+          pair.children[0].children[0]
+        end
+
+        def hash_key_value(pair)
+          pair.children[1].children[0]
+        end
+      end
+    end
+  end
+end
diff --git a/rubocop/cop/project_path_helper.rb b/rubocop/cop/project_path_helper.rb
new file mode 100644
index 00000000000..3e1ce71ac06
--- /dev/null
+++ b/rubocop/cop/project_path_helper.rb
@@ -0,0 +1,51 @@
+module RuboCop
+  module Cop
+    class ProjectPathHelper < RuboCop::Cop::Cop
+      MSG = 'Use short project path helpers without explicitly passing the namespace: ' \
+        '`foo_project_bar_path(project, bar)` instead of ' \
+        '`foo_namespace_project_bar_path(project.namespace, project, bar)`.'.freeze
+
+      METHOD_NAME_PATTERN = /\A([a-z_]+_)?namespace_project(?:_[a-z_]+)?_(?:url|path)\z/.freeze
+
+      def on_send(node)
+        return unless method_name(node).to_s =~ METHOD_NAME_PATTERN
+
+        namespace_expr, project_expr = arguments(node)
+        return unless namespace_expr && project_expr
+
+        return unless namespace_expr.type == :send
+        return unless method_name(namespace_expr) == :namespace
+        return unless receiver(namespace_expr) == project_expr
+
+        add_offense(node, :selector)
+      end
+
+      def autocorrect(node)
+        helper_name = method_name(node).to_s.sub('namespace_project', 'project')
+
+        arguments = arguments(node)
+        arguments.shift # Remove namespace argument
+
+        replacement = "#{helper_name}(#{arguments.map(&:source).join(', ')})"
+
+        lambda do |corrector|
+          corrector.replace(node.source_range, replacement)
+        end
+      end
+
+      private
+
+      def receiver(node)
+        node.children[0]
+      end
+
+      def method_name(node)
+        node.children[1]
+      end
+
+      def arguments(node)
+        node.children[2..-1]
+      end
+    end
+  end
+end