Introduce AllCops: MigratedSchemaVersion config

This PR introduces `AllCops: MigratedSchemaVersion` config.

By specifying the `MigratedSchemaVersion` option, migration files that have already been run can be ignored.
When `MigratedSchemaVersion: '20241225000000'` is set, migration files lower than or equal to '20241225000000' will be ignored.
For example, to ignore db/migrate/20241225000000_create_articles.rb and earlier migrations you would configure it the following way:

```yaml
AllCops
  MigratedSchemaVersion: '20241225000000'
```

This prevents inspecting schema settings for already applied migration files.
Changing already applied migrations should be avoided because it can lead to the schema getting out of sync
between your local copy and what it actually is in production, depending on when `bin/rails db:migrate` was executed.
If you want to modify your schema to comply with the cops, you should instead create new migrations.

README.md

@@ -83,6 +83,22 @@ gems.locked file to find the version of Rails that has been bound to the
 application. If neither of those files exist, RuboCop will use Rails 5.0
 as the default.
 
+### `AllCops: MigratedSchemaVersion`
+
+By specifying the `MigratedSchemaVersion` option, migration files that have already been run can be ignored.
+When `MigratedSchemaVersion: '20241225000000'` is set, migration files lower than or equal to '20241225000000' will be ignored.
+For example, to ignore db/migrate/20241225000000_create_articles.rb and earlier migrations you would configure it the following way:
+
+```yaml
+AllCops
+  MigratedSchemaVersion: '20241225000000'
+```
+
+This prevents inspecting schema settings for already applied migration files.
+Changing already applied migrations should be avoided because it can lead to the schema getting out of sync
+between your local copy and what it actually is in production, depending on when `bin/rails db:migrate` was executed.
+If you want to modify your schema to comply with the cops, you should instead create new migrations.
+
 ## Rails configuration tip
 
 In Rails 6.1+, add the following `config.generators.after_generate` setting to

changelog/new_intro_migrated_schema_version.md

@@ -0,0 +1 @@
+* [#1383](https://github.com/rubocop/rubocop-rails/pull/1383): Introduce `AllCops: MigratedSchemaVersion` config. ([@koic][])

config/default.yml

@@ -25,6 +25,10 @@ AllCops:
   # application. If neither of those files exist, RuboCop will use Rails 5.0
   # as the default.
   TargetRailsVersion: ~
+  # By specifying `MigratedSchemaVersion` option, migration files that have been migrated can be ignored.
+  # When `MigratedSchemaVersion: '20241231000000'` is set. Migration files lower than or equal to '20250101000000' will be ignored.
+  # For example, this is the timestamp in db/migrate/20250101000000_create_articles.rb.
+  MigratedSchemaVersion: ~
 
 Lint/NumberConversion:
   # Add Rails' duration methods to the ignore list for `Lint/NumberConversion`

docs/modules/ROOT/pages/usage.adoc

@@ -52,6 +52,23 @@ gems.locked file to find the version of Rails that has been bound to the
 application. If neither of those files exist, RuboCop will use Rails 5.0
 as the default.
 
+=== `AllCops: MigratedSchemaVersion`
+
+By specifying the `MigratedSchemaVersion` option, migration files that have already been run can be ignored.
+When `MigratedSchemaVersion: '20241225000000'` is set, migration files lower than or equal to '20241225000000' will be ignored.
+For example, to ignore db/migrate/20241225000000_create_articles.rb and earlier migrations you would configure it the following way:
+
+[source,yaml]
+----
+AllCops
+  MigratedSchemaVersion: '20241225000000'
+----
+
+This prevents inspecting schema settings for already applied migration files.
+Changing already applied migrations should be avoided because it can lead to the schema getting out of sync
+between your local copy and what it actually is in production, depending on when `bin/rails db:migrate` was executed.
+If you want to modify your schema to comply with the cops, you should instead create new migrations.
+
 == Rails configuration tip
 
 In Rails 6.1+, add the following `config.generators.after_generate` setting to

lib/rubocop/cop/mixin/migrations_helper.rb

@@ -21,6 +21,35 @@ def in_migration?(node)
           migration_class?(class_node)
         end
       end
+
+      # rubocop:disable Style/DocumentDynamicEvalDefinition
+      %i[on_send on_csend on_block on_numblock on_class].each do |method|
+        class_eval(<<~RUBY, __FILE__, __LINE__ + 1)
+          def #{method}(node)
+            return if already_migrated_file?
+
+            super if method(__method__).super_method
+          end
+        RUBY
+      end
+      # rubocop:enable Style/DocumentDynamicEvalDefinition
+
+      private
+
+      def already_migrated_file?
+        return false unless migrated_schema_version
+
+        match_data = File.basename(processed_source.file_path).match(/(?<timestamp>\d{14})/)
+        schema_version = match_data['timestamp'] if match_data
+
+        return false unless schema_version
+
+        schema_version <= migrated_schema_version.to_s # Ignore applied migration files.
+      end
+
+      def migrated_schema_version
+        config.for_all_cops.fetch('MigratedSchemaVersion', nil)
+      end
     end
   end
 end

lib/rubocop/cop/rails/add_column_index.rb

@@ -19,6 +19,7 @@ module Rails
       class AddColumnIndex < Base
         extend AutoCorrector
         include RangeHelp
+        prepend MigrationsHelper
 
         MSG = '`add_column` does not accept an `index` key, use `add_index` instead.'
         RESTRICT_ON_SEND = %i[add_column].freeze

lib/rubocop/cop/rails/bulk_change_table.rb

@@ -65,6 +65,7 @@ module Rails
       #   end
       class BulkChangeTable < Base
         include DatabaseTypeResolvable
+        prepend MigrationsHelper
 
         MSG_FOR_CHANGE_TABLE = <<~MSG.chomp
           You can combine alter queries using `bulk: true` options.

lib/rubocop/cop/rails/dangerous_column_names.rb

@@ -14,6 +14,8 @@ module Rails
       #   # good
       #   add_column :users, :saved
       class DangerousColumnNames < Base # rubocop:disable Metrics/ClassLength
+        prepend MigrationsHelper
+
         COLUMN_TYPE_METHOD_NAMES = %i[
           bigint
           binary

lib/rubocop/cop/rails/migration_class_name.rb

@@ -20,7 +20,7 @@ module Rails
       #
       class MigrationClassName < Base
         extend AutoCorrector
-        include MigrationsHelper
+        prepend MigrationsHelper
 
         MSG = 'Replace with `%<camelized_basename>s` that matches the file name.'
 

lib/rubocop/cop/rails/not_null_column.rb

@@ -41,6 +41,7 @@ module Rails
       #   change_column_null :products, :category_id, false
       class NotNullColumn < Base
         include DatabaseTypeResolvable
+        prepend MigrationsHelper
 
         MSG = 'Do not add a NOT NULL column without a default value.'
         RESTRICT_ON_SEND = %i[add_column add_reference].freeze

lib/rubocop/cop/rails/reversible_migration.rb

@@ -151,7 +151,7 @@ module Rails
       #     remove_index :users, column: :email
       #   end
       class ReversibleMigration < Base
-        include MigrationsHelper
+        prepend MigrationsHelper
 
         MSG = '%<action>s is not reversible.'
 

lib/rubocop/cop/rails/reversible_migration_method_definition.rb

@@ -43,7 +43,7 @@ module Rails
       #     end
       #   end
       class ReversibleMigrationMethodDefinition < Base
-        include MigrationsHelper
+        prepend MigrationsHelper
 
         MSG = 'Migrations must contain either a `change` method, or both an `up` and a `down` method.'
 

lib/rubocop/cop/rails/schema_comment.rb

@@ -23,6 +23,7 @@ module Rails
       #
       class SchemaComment < Base
         include ActiveRecordMigrationsHelper
+        prepend MigrationsHelper
 
         COLUMN_MSG = 'New database column without `comment`.'
         TABLE_MSG = 'New database table without `comment`.'

lib/rubocop/cop/rails/three_state_boolean_column.rb

@@ -18,8 +18,9 @@ module Rails
       #   t.boolean :active, default: true, null: false
       #
       class ThreeStateBooleanColumn < Base
-        MSG = 'Boolean columns should always have a default value and a `NOT NULL` constraint.'
+        prepend MigrationsHelper
 
+        MSG = 'Boolean columns should always have a default value and a `NOT NULL` constraint.'
         RESTRICT_ON_SEND = %i[add_column column boolean].freeze
 
         def_node_matcher :three_state_boolean?, <<~PATTERN

spec/rubocop/cop/rails/add_column_index_spec.rb

@@ -1,8 +1,12 @@
 # frozen_string_literal: true
 
 RSpec.describe RuboCop::Cop::Rails::AddColumnIndex, :config do
+  let(:config) do
+    RuboCop::Config.new('AllCops' => { 'MigratedSchemaVersion' => '20240101010101' })
+  end
+
   it 'registers an offense and corrects when an `add_column` call has `index: true`' do
-    expect_offense(<<~RUBY)
+    expect_offense(<<~RUBY, '20250101010101_add_column_to_table.rb')
       add_column :table, :column, :integer, default: 0, index: true
                                                         ^^^^^^^^^^^ `add_column` does not accept an `index` key, use `add_index` instead.
     RUBY
@@ -14,7 +18,7 @@
   end
 
   it 'registers an offense and corrects when an `add_column` call has `index:` with a hash' do
-    expect_offense(<<~RUBY)
+    expect_offense(<<~RUBY, '20250101010101_add_column_to_table.rb')
       add_column :table, :column, :integer, default: 0, index: { unique: true, name: 'my_unique_index' }
                                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `add_column` does not accept an `index` key, use `add_index` instead.
     RUBY
@@ -26,7 +30,7 @@
   end
 
   it 'registers an offense and corrects with there is another hash key after `index`' do
-    expect_offense(<<~RUBY)
+    expect_offense(<<~RUBY, '20250101010101_add_column_to_table.rb')
       add_column :table, :column, :integer, index: true, default: 0
                                             ^^^^^^^^^^^ `add_column` does not accept an `index` key, use `add_index` instead.
     RUBY
@@ -38,7 +42,7 @@
   end
 
   it 'registers an offense and corrects with string keys' do
-    expect_offense(<<~RUBY)
+    expect_offense(<<~RUBY, '20250101010101_add_column_to_table.rb')
       add_column :table, :column, :integer, 'index' => true, default: 0
                                             ^^^^^^^^^^^^^^^ `add_column` does not accept an `index` key, use `add_index` instead.
     RUBY
@@ -50,7 +54,7 @@
   end
 
   it 'registers an offense and corrects when on multiple lines' do
-    expect_offense(<<~RUBY)
+    expect_offense(<<~RUBY, '20250101010101_add_column_to_table.rb')
       add_column :table, :column, :integer,
                  index: true,
                  ^^^^^^^^^^^ `add_column` does not accept an `index` key, use `add_index` instead.
@@ -65,7 +69,7 @@
   end
 
   it 'can correct multiple `add_column` calls' do
-    expect_offense(<<~RUBY)
+    expect_offense(<<~RUBY, '20250101010101_add_column_to_table.rb')
       add_column :table, :column, :integer, default: 0, index: true
                                                         ^^^^^^^^^^^ `add_column` does not accept an `index` key, use `add_index` instead.
       add_column :table, :column2, :integer, default: 0, index: true
@@ -85,4 +89,22 @@
       add_column :table, :column, :integer, default: 0
     RUBY
   end
+
+  context '`MigratedSchemaVersion` is an integer' do
+    let(:config) do
+      RuboCop::Config.new('AllCops' => { 'MigratedSchemaVersion' => 20240101010101 }) # rubocop:disable Style/NumericLiterals
+    end
+
+    it 'registers an offense and corrects when an `add_column` call has `index: true`' do
+      expect_offense(<<~RUBY, '20250101010101_add_column_to_table.rb')
+        add_column :table, :column, :integer, default: 0, index: true
+                                                          ^^^^^^^^^^^ `add_column` does not accept an `index` key, use `add_index` instead.
+      RUBY
+
+      expect_correction(<<~RUBY)
+        add_column :table, :column, :integer, default: 0
+        add_index :table, :column
+      RUBY
+    end
+  end
 end

spec/rubocop/cop/rails/dangerous_column_names_spec.rb

@@ -1,6 +1,10 @@
 # frozen_string_literal: true
 
 RSpec.describe RuboCop::Cop::Rails::DangerousColumnNames, :config do
+  let(:config) do
+    RuboCop::Config.new('AllCops' => { 'MigratedSchemaVersion' => '20240101010101' })
+  end
+
   context 'with non-dangerous column name' do
     it 'does not register an offense' do
       expect_no_offenses(<<~RUBY)
@@ -18,6 +22,14 @@
     end
   end
 
+  context 'with dangerous column name on `add_column` when migration file was migrated' do
+    it 'does not register an offense' do
+      expect_no_offenses(<<~RUBY, '20190101010101_add_save_to_users.rb')
+        add_column :users, :save, :string
+      RUBY
+    end
+  end
+
   context 'with dangerous column name on `rename_column`' do
     it 'registers an offense' do
       expect_offense(<<~RUBY)
@@ -29,7 +41,7 @@
 
   context 'with dangerous column name on `t.string`' do
     it 'registers an offense' do
-      expect_offense(<<~RUBY)
+      expect_offense(<<~RUBY, '20250101010101_create_users.rb')
         create_table :users do |t|
           t.string :save
                    ^^^^^ Avoid dangerous column names.
@@ -40,7 +52,7 @@
 
   context 'with dangerous column name on `t.rename`' do
     it 'registers an offense' do
-      expect_offense(<<~RUBY)
+      expect_offense(<<~RUBY, '20250101010101_create_users.rb')
         create_table :users do |t|
           t.rename :name, :save
                           ^^^^^ Avoid dangerous column names.

spec/rubocop/cop/rails/migration_class_name_spec.rb

@@ -1,7 +1,10 @@
 # frozen_string_literal: true
 
 RSpec.describe RuboCop::Cop::Rails::MigrationClassName, :config do
-  let(:filename) { 'db/migrate/20220101050505_create_users.rb' }
+  let(:config) do
+    RuboCop::Config.new('AllCops' => { 'MigratedSchemaVersion' => '20240101010101' })
+  end
+  let(:filename) { 'db/migrate/20250101010101_create_users.rb' }
 
   context 'when the class name matches its file name' do
     it 'does not register an offense' do
@@ -85,7 +88,7 @@ class AddBlobs < ActiveRecord::Migration[7.0]
   # end
   #
   context 'when `ActiveSupport::Inflector` is applied to the class name and the case is different' do
-    let(:filename) { 'db/migrate/20210623095243_remove_unused_oauth_scope_grants.rb' }
+    let(:filename) { 'db/migrate/20250101010101_remove_unused_oauth_scope_grants.rb' }
 
     it 'does not register an offense' do
       expect_no_offenses(<<~RUBY, filename)