4 files changed, 58 insertions, 1 deletions
diff --git a/rubocop/cop/migration/add_concurrent_index.rb b/rubocop/cop/migration/add_concurrent_index.rb
index 332fb7dcbd7..69852f4d580 100644
--- a/rubocop/cop/migration/add_concurrent_index.rb
+++ b/rubocop/cop/migration/add_concurrent_index.rb
@@ -9,7 +9,7 @@ module RuboCop
         include MigrationHelpers
 
         MSG = '`add_concurrent_index` is not reversible so you must manually define ' \
-          'the `up` and `down` methods in your migration class, using `remove_index` in `down`'.freeze
+          'the `up` and `down` methods in your migration class, using `remove_concurrent_index` in `down`'.freeze
 
         def on_send(node)
           return unless in_migration?(node)
diff --git a/rubocop/cop/migration/remove_concurrent_index.rb b/rubocop/cop/migration/remove_concurrent_index.rb
new file mode 100644
index 00000000000..268c49865cb
--- /dev/null
+++ b/rubocop/cop/migration/remove_concurrent_index.rb
@@ -0,0 +1,29 @@
+require_relative '../../migration_helpers'
+
+module RuboCop
+  module Cop
+    module Migration
+      # Cop that checks if `remove_concurrent_index` is used with `up`/`down` methods
+      # and not `change`.
+      class RemoveConcurrentIndex < RuboCop::Cop::Cop
+        include MigrationHelpers
+
+        MSG = '`remove_concurrent_index` is not reversible so you must manually define ' \
+          'the `up` and `down` methods in your migration class, using `add_concurrent_index` in `down`'.freeze
+
+        def on_send(node)
+          return unless in_migration?(node)
+          return unless node.children[1] == :remove_concurrent_index
+
+          node.each_ancestor(:def) do |def_node|
+            add_offense(def_node, :name) if method_name(def_node) == :change
+          end
+        end
+
+        def method_name(node)
+          node.children[0]
+        end
+      end
+    end
+  end
+end
diff --git a/rubocop/cop/migration/remove_index.rb b/rubocop/cop/migration/remove_index.rb
new file mode 100644
index 00000000000..613b35dd00d
--- /dev/null
+++ b/rubocop/cop/migration/remove_index.rb
@@ -0,0 +1,26 @@
+require_relative '../../migration_helpers'
+
+module RuboCop
+  module Cop
+    module Migration
+      # Cop that checks if indexes are removed in a concurrent manner.
+      class RemoveIndex < RuboCop::Cop::Cop
+        include MigrationHelpers
+
+        MSG = '`remove_index` requires downtime, use `remove_concurrent_index` instead'.freeze
+
+        def on_def(node)
+          return unless in_migration?(node)
+
+          node.each_descendant(:send) do |send_node|
+            add_offense(send_node, :selector) if method_name(send_node) == :remove_index
+          end
+        end
+
+        def method_name(node)
+          node.children[1]
+        end
+      end
+    end
+  end
+end
diff --git a/rubocop/rubocop.rb b/rubocop/rubocop.rb
index a50a522cf9d..d580aa6857a 100644
--- a/rubocop/rubocop.rb
+++ b/rubocop/rubocop.rb
@@ -5,3 +5,5 @@ require_relative 'cop/migration/add_column_with_default'
 require_relative 'cop/migration/add_concurrent_foreign_key'
 require_relative 'cop/migration/add_concurrent_index'
 require_relative 'cop/migration/add_index'
+require_relative 'cop/migration/remove_concurrent_index'
+require_relative 'cop/migration/remove_index'