Drop support for ruby < 2.7 and rails < 6.1

.github/workflows/test.yml

@@ -33,17 +33,7 @@ jobs:
     strategy:
       matrix:
         include:
-          - ruby-version: 2.4
-            gemfile: activerecord_42.gemfile
-          - ruby-version: 2.4
-            gemfile: activerecord_50.gemfile
-          - ruby-version: 2.4
-            gemfile: activerecord_51.gemfile
-          - ruby-version: 2.4
-            gemfile: activerecord_52.gemfile
-          - ruby-version: 2.5
-            gemfile: activerecord_60.gemfile
-          - ruby-version: 2.5
+          - ruby-version: 2.7
             gemfile: activerecord_61.gemfile
           - ruby-version: 2.7
             gemfile: activerecord_70.gemfile

.rubocop.yml

@@ -3,7 +3,7 @@ require:
   - rubocop-disable_syntax
 
 AllCops:
-  TargetRubyVersion: 2.3
+  TargetRubyVersion: 2.7
   NewCops: enable
   SuggestExtensions: false
 

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## master (unreleased)
 
+- Drop support for Ruby < 2.7 and Rails < 6.1
 - Fix `backfill_column_for_type_change_in_background` for cast expressions
 - Fix copying indexes with long names when changing column type
 - Enhance error messages with the link to the detailed description

Gemfile.lock

@@ -2,7 +2,7 @@ PATH
   remote: .
   specs:
     online_migrations (0.9.2)
-      activerecord (>= 4.2)
+      activerecord (>= 6.1)
 
 GEM
   remote: https://rubygems.org/

README.md

@@ -16,10 +16,12 @@ See [comparison to `strong_migrations`](#comparison-to-strong_migrations)
 
 ## Requirements
 
-- Ruby 2.1+
-- Rails 4.2+
+- Ruby 2.7+
+- Rails 6.1+
 - PostgreSQL 9.6+
 
+For older Ruby and Rails versions you can use '< 0.10' version of this gem.
+
 **Note**: Since some migration helpers use database `VIEW`s to implement their logic, it is recommended to use `structure.sql` schema format, or otherwise add some gem (like [scenic](https://github.com/scenic-views/scenic)) to be able to dump them into the `schema.rb`.
 
 ## Installation

lib/generators/online_migrations/install_generator.rb

@@ -15,20 +15,16 @@ def copy_initializer_file
     end
 
     def create_migration_file
-      migration_template("migration.rb", File.join(migrations_dir, "install_online_migrations.rb"))
+      migration_template("migration.rb", File.join(db_migrate_path, "install_online_migrations.rb"))
     end
 
     private
       def migration_parent
-        Utils.migration_parent_string
+        "ActiveRecord::Migration[#{Utils.ar_version}]"
       end
 
       def start_after
-        self.class.current_migration_number(migrations_dir)
-      end
-
-      def migrations_dir
-        Utils.ar_version >= 5.1 ? db_migrate_path : "db/migrate"
+        self.class.current_migration_number(db_migrate_path)
       end
   end
 end

lib/online_migrations.rb

@@ -17,7 +17,6 @@ class UnsafeMigration < Error; end
   autoload :Migration
   autoload :Migrator
   autoload :DatabaseTasks
-  autoload :ForeignKeyDefinition
   autoload :ForeignKeysCollector
   autoload :IndexDefinition
   autoload :IndexesCollector
@@ -90,10 +89,6 @@ def load
       else
         ActiveRecord::ConnectionAdapters::SchemaCache.prepend(OnlineMigrations::SchemaCache)
       end
-
-      if OnlineMigrations::Utils.ar_version <= 5.1
-        ActiveRecord::ConnectionAdapters::ForeignKeyDefinition.prepend(OnlineMigrations::ForeignKeyDefinition)
-      end
     end
   end
 end

lib/online_migrations/background_migrations/advisory_lock.rb

@@ -37,7 +37,7 @@ def active?
         objid = lock_key & 0xffffffff
         classid = (lock_key & (0xffffffff << 32)) >> 32
 
-        active = connection.select_value(<<-SQL.strip_heredoc)
+        active = connection.select_value(<<~SQL)
           SELECT granted
           FROM pg_locks
           WHERE locktype = 'advisory'

lib/online_migrations/background_migrations/backfill_column.rb

@@ -22,7 +22,7 @@ def relation
           quoted_column = connection.quote_column_name(column)
           model.unscoped.where("#{quoted_column} != ? OR #{quoted_column} IS NULL", value)
         else
-          Utils.ar_where_not_multiple_conditions(model.unscoped, updates)
+          model.unscoped.where.not(updates)
         end
       end
 

lib/online_migrations/background_migrations/copy_column.rb

@@ -25,14 +25,10 @@ def initialize(table_name, copy_from, copy_to, model_name = nil, type_cast_funct
       end
 
       def relation
-        relation = model
+        model
           .unscoped
-          .where(copy_to.map { |to_column| [to_column, nil] }.to_h)
-
-        Utils.ar_where_not_multiple_conditions(
-          relation,
-          copy_from.map { |from_column| [from_column, nil] }.to_h
-        )
+          .where(copy_to.index_with(nil))
+          .where.not(copy_from.index_with(nil))
       end
 
       def process_batch(relation)
@@ -43,13 +39,8 @@ def process_batch(relation)
           old_value = arel_table[from_column]
           if (type_cast_function = type_cast_functions[from_column])
             old_value =
-              if type_cast_function =~ /\A\w+\z/
-                if Utils.ar_version <= 5.2
-                  # Active Record <= 5.2 does not support quoting of Arel::Nodes::NamedFunction
-                  Arel.sql("#{type_cast_function}(#{connection.quote_column_name(from_column)})")
-                else
-                  Arel::Nodes::NamedFunction.new(type_cast_function, [old_value])
-                end
+              if type_cast_function.match?(/\A\w+\z/)
+                Arel::Nodes::NamedFunction.new(type_cast_function, [old_value])
               else
                 # We got a cast expression.
                 Arel.sql(type_cast_function)
@@ -58,12 +49,7 @@ def process_batch(relation)
           old_value
         end
 
-        if Utils.ar_version <= 4.2
-          stmt = Arel::UpdateManager.new(arel.engine)
-        else
-          stmt = Arel::UpdateManager.new
-        end
-
+        stmt = Arel::UpdateManager.new
         stmt.table(arel_table)
         stmt.wheres = arel.constraints
 

lib/online_migrations/background_migrations/delete_orphaned_records.rb

@@ -12,29 +12,11 @@ def initialize(model_name, associations, _options = {})
       end
 
       def relation
-        # For Active Record 6.1+ we can use `where.missing`
-        # https://github.com/rails/rails/pull/34727
-        associations.inject(model.unscoped) do |relation, association|
-          reflection = model.reflect_on_association(association)
-          if reflection.nil?
-            raise ArgumentError, "'#{model.name}' has no association called '#{association}'"
-          end
-
-          # left_joins was added in Active Record 5.0 - https://github.com/rails/rails/pull/12071
-          relation
-            .left_joins(association)
-            .where(reflection.table_name => { reflection.association_primary_key => nil })
-        end
+        model.unscoped.where.missing(*associations)
       end
 
       def process_batch(relation)
-        if Utils.ar_version > 5.0
-          relation.delete_all
-        else
-          # Older Active Record generates incorrect query when running delete_all
-          primary_key = model.primary_key
-          model.unscoped.where(primary_key => relation.select(primary_key)).delete_all
-        end
+        relation.delete_all
       end
 
       def count

lib/online_migrations/background_migrations/migration.rb

@@ -21,7 +21,7 @@ class Migration < ActiveRecord::Base
         for_migration_name(migration_name).where("arguments = ?", arguments.to_json)
       end
 
-      enum status: STATUSES.map { |status| [status, status.to_s] }.to_h
+      enum status: STATUSES.index_with(&:to_s)
 
       has_many :migration_jobs
 
@@ -138,16 +138,10 @@ def next_batch_range
 
         # rubocop:disable Lint/UnreachableLoop
         iterator.each_batch(of: batch_size, column: batch_column_name, start: next_min_value) do |relation|
-          if Utils.ar_version <= 4.2
-            # Active Record <= 4.2 does not support pluck with Arel nodes
-            quoted_column = self.class.connection.quote_column_name(batch_column_name)
-            batch_range = relation.pluck("MIN(#{quoted_column}), MAX(#{quoted_column})").first
-          else
-            min = relation.arel_table[batch_column_name].minimum
-            max = relation.arel_table[batch_column_name].maximum
+          min = relation.arel_table[batch_column_name].minimum
+          max = relation.arel_table[batch_column_name].maximum
+          batch_range = relation.pick(min, max)
 
-            batch_range = relation.pluck(min, max).first
-          end
           break
         end
         # rubocop:enable Lint/UnreachableLoop

lib/online_migrations/background_migrations/migration_helpers.rb

@@ -223,10 +223,6 @@ def reset_counters_in_background(model_name, *counters, touch: nil, **options)
       #     For smaller tables it is probably better and easier to directly find and delete orpahed records.
       #
       def delete_orphaned_records_in_background(model_name, *associations, **options)
-        if Utils.ar_version <= 4.2
-          raise "#{__method__} does not support Active Record <= 4.2 yet"
-        end
-
         model_name = model_name.name if model_name.is_a?(Class)
 
         enqueue_background_migration(

lib/online_migrations/background_migrations/migration_job.rb

@@ -12,9 +12,8 @@ class MigrationJob < ActiveRecord::Base
 
       self.table_name = :background_migration_jobs
 
-      # For Active Record <= 4.2 needs to fully specify enum values
-      scope :active, -> { where(status: [statuses[:enqueued], statuses[:running]]) }
-      scope :completed, -> { where(status: [statuses[:failed], statuses[:succeeded]]) }
+      scope :active, -> { where(status: [:enqueued, :running]) }
+      scope :completed, -> { where(status: [:failed, :succeeded]) }
       scope :stuck, -> do
         timeout = ::OnlineMigrations.config.background_migrations.stuck_jobs_timeout
         active.where("updated_at <= ?", timeout.ago)
@@ -26,7 +25,7 @@ class MigrationJob < ActiveRecord::Base
         stuck_sql             = connection.unprepared_statement { stuck.to_sql }
         failed_retriable_sql  = connection.unprepared_statement { failed_retriable.to_sql }
 
-        from(Arel.sql(<<-SQL.strip_heredoc))
+        from(Arel.sql(<<~SQL))
           (
             (#{failed_retriable_sql})
             UNION
@@ -35,19 +34,16 @@ class MigrationJob < ActiveRecord::Base
         SQL
       end
 
-      scope :except_succeeded, -> { where("status != ?", statuses[:succeeded]) }
+      scope :except_succeeded, -> { where.not(status: :succeeded) }
       scope :attempts_exceeded, -> { where("attempts >= max_attempts") }
 
-      enum status: STATUSES.map { |status| [status, status.to_s] }.to_h
+      enum status: STATUSES.index_with(&:to_s)
 
       delegate :migration_class, :migration_object, :migration_relation, :batch_column_name,
         :arguments, :batch_pause, to: :migration
 
       belongs_to :migration
 
-      # For Active Record 5.0+ this is validated by default from belongs_to
-      validates :migration, presence: true
-
       validates :min_value, :max_value, presence: true, numericality: { greater_than: 0 }
       validate :values_in_migration_range, if: :min_value?
       validate :validate_values_order, if: :min_value?

lib/online_migrations/background_migrations/reset_counters.rb

@@ -26,7 +26,7 @@ def process_batch(relation)
           counter_name = reflection.counter_cache_column
 
           quoted_association_table = connection.quote_table_name(has_many_association.table_name)
-          count_subquery = <<-SQL.strip_heredoc
+          count_subquery = <<~SQL
             SELECT COUNT(*)
             FROM #{quoted_association_table}
             WHERE #{quoted_association_table}.#{connection.quote_column_name(foreign_key)} =
@@ -41,8 +41,7 @@ def process_batch(relation)
           names = Array.wrap(names)
           options = names.extract_options!
           touch_updates = touch_attributes_with_time(*names, **options)
-          # In Active Record 4.2 sanitize_sql_for_assignment is protected
-          updates << model.send(:sanitize_sql_for_assignment, touch_updates)
+          updates << model.sanitize_sql_for_assignment(touch_updates)
         end
 
         relation.update_all(updates.join(", "))
@@ -64,11 +63,6 @@ def has_many_association(counter_association) # rubocop:disable Naming/Predicate
 
             has_many_association = has_many.find do |association|
               counter_cache_column = association.counter_cache_column
-
-              # Active Record <= 4.2 is able to return only explicitly provided `counter_cache` column.
-              if !counter_cache_column && Utils.ar_version <= 4.2
-                counter_cache_column = "#{association.name}_count"
-              end
               counter_cache_column && counter_cache_column.to_sym == counter_association.to_sym
             end
 
@@ -86,7 +80,7 @@ def has_many_association(counter_association) # rubocop:disable Naming/Predicate
         def touch_attributes_with_time(*names, time: nil)
           attribute_names = timestamp_attributes_for_update & model.column_names
           attribute_names |= names.map(&:to_s)
-          attribute_names.map { |attribute_name| [attribute_name, time || Time.current] }.to_h
+          attribute_names.index_with(time || Time.current)
         end
 
         def timestamp_attributes_for_update