Update db:migrate:up & db:migrate:down to act more like active record one

lib/sequel_rails/migrations.rb

@@ -3,13 +3,12 @@
 module SequelRails
   class Migrations
     class << self
-      def migrate(version = nil)
-        opts = {}
+      def migrate(version = nil, migrator_class = ::Sequel::Migrator, opts = {})
         opts[:target] = version.to_i if version
         opts[:allow_missing_migration_files] = !!SequelRails.configuration.allow_missing_migration_files
 
         if migrations_dir.directory?
-          ::Sequel::Migrator.run(::Sequel::Model.db, migrations_dir, opts)
+          migrator_class.run(::Sequel::Model.db, migrations_dir, opts)
         else
           relative_path_name = migrations_dir.relative_path_from(Rails.root).to_s
           raise "The #{relative_path_name} directory doesn't exist, you need to create it."
@@ -18,6 +17,14 @@ def migrate(version = nil)
       alias_method :migrate_up!, :migrate
       alias_method :migrate_down!, :migrate
 
+      def migrate_up_one_version!(version)
+        migrate(version, SequelRails::OneTimestampVersionMigrator, { direction: :up })
+      end
+
+      def migrate_down_one_version!(version)
+        migrate(version, SequelRails::OneTimestampVersionMigrator, { direction: :down })
+      end
+
       def pending_migrations?
         return false unless available_migrations?
         !::Sequel::Migrator.is_current?(::Sequel::Model.db, migrations_dir)
@@ -78,4 +85,50 @@ def init_migrator
       end
     end
   end
+
+  class OneTimestampVersionMigrator < ::Sequel::TimestampMigrator
+    Error = ::Sequel::Migrator::Error
+
+    # The direction of the migrator, either :up or :down
+    attr_reader :direction
+
+    # Set up all state for the migrator instance
+    def initialize(db, directory, opts = OPTS)
+      @direction = opts[:direction]
+      super
+
+      raise(Error, 'target (version) is absent') if target.nil?
+      raise(Error, "Invalid direction: #{direction}") unless [:up, :down].include?(direction)
+      # `allow_missing_migration_files` ignored, as version is from user input
+      raise(Error, "Migration with version #{target} not found") if migration_tuples.empty?
+    end
+
+    private
+
+    # This is overriding parent method, no way to choose another method name
+    # rubocop:disable Naming/AccessorMethodName
+    def get_migration_tuples
+      up_mts = []
+      down_mts = []
+      files.each do |path|
+        f = File.basename(path)
+        fi = f.downcase
+        next unless migration_version_from_file(f) == target
+
+        case [direction, applied_migrations.include?(fi)]
+        when [:up, false]
+          # Normal migrate up
+          up_mts << [load_migration_file(path), f, :up]
+        when [:down, true]
+          # Normal migrate down
+          down_mts << [load_migration_file(path), f, :down]
+        else
+          # Already run, don't re-run
+          raise(Error, "Migration with version #{target} is already migrated/rollback")
+        end
+      end
+      up_mts + down_mts.reverse
+    end
+    # rubocop:enable Naming/AccessorMethodName
+  end
 end

lib/sequel_rails/railties/database.rake

@@ -154,15 +154,15 @@ namespace sequel_rails_namespace do
     task :up => :load do
       version = ENV['VERSION'] ? ENV['VERSION'].to_i : nil
       raise 'VERSION is required' unless version
-      SequelRails::Migrations.migrate_up!(version)
+      SequelRails::Migrations.migrate_up_one_version!(version)
       Rake::Task["#{sequel_rails_namespace}:dump"].invoke if SequelRails.configuration.schema_dump
     end
 
     desc 'Runs the "down" for a given migration VERSION.'
     task :down => :load do
       version = ENV['VERSION'] ? ENV['VERSION'].to_i : nil
       raise 'VERSION is required' unless version
-      SequelRails::Migrations.migrate_down!(version)
+      SequelRails::Migrations.migrate_down_one_version!(version)
       Rake::Task["#{sequel_rails_namespace}:dump"].invoke if SequelRails.configuration.schema_dump
     end
   end

spec/lib/sequel_rails/railties/database_rake_spec.rb

@@ -81,6 +81,219 @@
     end
   end
 
+  describe 'db:migrate:up' do
+    let(:version) { nil }
+    around do |example|
+      env_value_before = ENV['VERSION']
+      ENV['VERSION'] = version
+      example.run
+      ENV['VERSION'] = env_value_before
+    end
+    let(:rake_task_call) do
+      proc { Rake::Task['db:migrate:up'].execute }
+    end
+
+    context 'when no version supplied' do
+      it 'raises error' do
+        Dir.chdir app_root do
+          begin
+            expect do
+              rake_task_call.call
+            end.to raise_error('VERSION is required')
+          ensure
+            SequelRails::Migrations.migrate_up!
+          end
+        end
+      end
+    end
+
+    context 'when version with no matching migration supplied' do
+      let(:version) { '1273253848' }
+
+      it 'raises error' do
+        Dir.chdir app_root do
+          begin
+            expect do
+              rake_task_call.call
+            end.to raise_error("Migration with version #{version} not found")
+          ensure
+            SequelRails::Migrations.migrate_up!
+          end
+        end
+      end
+    end
+
+    context 'when version with matching migration supplied' do
+      let(:version) { '1273253849' }
+
+      context 'and migration already run' do
+        it 'raises error' do
+          Dir.chdir app_root do
+            begin
+              expect do
+                rake_task_call.call
+              end.to raise_error("Migration with version #{version} is already migrated/rollback")
+            ensure
+              SequelRails::Migrations.migrate_up!
+            end
+          end
+        end
+      end
+
+      context 'and migration NOT already run' do
+        context 'and target migration is 1 version later than current migration' do
+          before do
+            Dir.chdir app_root do
+              SequelRails::Migrations.migrate_down!(0)
+            end
+          end
+
+          it 'runs the matching migration ONLY' do
+            Dir.chdir app_root do
+              begin
+                expect do
+                  rake_task_call.call
+                end.to change { SequelRails::Migrations.current_migration }
+                  .from(nil)
+                  .to('1273253849_add_twitter_handle_to_users.rb')
+              ensure
+                SequelRails::Migrations.migrate_up!
+              end
+            end
+          end
+        end
+
+        context 'and target migration is > 1 version later than current migration' do
+          let(:version) { '1365762739' }
+          before do
+            Dir.chdir app_root do
+              SequelRails::Migrations.migrate_down!(0)
+            end
+          end
+
+          it 'runs the matching migration ONLY' do
+            Dir.chdir app_root do
+              begin
+                expect do
+                  rake_task_call.call
+                end.to change {
+                  {
+                    current_migration: SequelRails::Migrations.current_migration,
+                    previous_migration: SequelRails::Migrations.previous_migration
+                  }
+                }
+                  .from({
+                    current_migration: nil,
+                    previous_migration: '0'
+                  })
+                  .to({
+                    current_migration: '1365762739_add_github_username_to_users.rb',
+                    previous_migration: '0'
+                  })
+              ensure
+                SequelRails::Migrations.migrate_up!
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+
+  describe 'db:migrate:down' do
+    let(:version) { nil }
+    around do |example|
+      env_value_before = ENV['VERSION']
+      ENV['VERSION'] = version
+      example.run
+      ENV['VERSION'] = env_value_before
+    end
+    let(:rake_task_call) do
+      proc { Rake::Task['db:migrate:down'].execute }
+    end
+
+    context 'when no version supplied' do
+      it 'raises error' do
+        Dir.chdir app_root do
+          begin
+            expect do
+              rake_task_call.call
+            end.to raise_error('VERSION is required')
+          ensure
+            SequelRails::Migrations.migrate_up!
+          end
+        end
+      end
+    end
+
+    context 'when version with no matching migration supplied' do
+      let(:version) { '1273253848' }
+
+      it 'raises error' do
+        Dir.chdir app_root do
+          begin
+            expect do
+              rake_task_call.call
+            end.to raise_error("Migration with version #{version} not found")
+          ensure
+            SequelRails::Migrations.migrate_up!
+          end
+        end
+      end
+    end
+
+    context 'when version with matching migration supplied' do
+      let(:version) { '1365762738' }
+
+      context 'and migration already run' do
+        it 'reverts the matching migration ONLY' do
+          Dir.chdir app_root do
+            begin
+              expect do
+                rake_task_call.call
+              end.to change {
+                {
+                  current_migration: SequelRails::Migrations.current_migration,
+                  previous_migration: SequelRails::Migrations.previous_migration
+                }
+              }
+                .from({
+                  current_migration: '1365762739_add_github_username_to_users.rb',
+                  previous_migration: '1365762738_add_display_name_to_users.rb'
+                })
+                .to({
+                  current_migration: '1365762739_add_github_username_to_users.rb',
+                  previous_migration: '1273253849_add_twitter_handle_to_users.rb'
+                })
+            ensure
+              SequelRails::Migrations.migrate_up!
+            end
+          end
+        end
+      end
+
+      context 'and migration NOT already run' do
+        before do
+          Dir.chdir app_root do
+            SequelRails::Migrations.migrate_down!(0)
+          end
+        end
+
+        it 'raises error' do
+          Dir.chdir app_root do
+            begin
+              expect do
+                rake_task_call.call
+              end.to raise_error("Migration with version #{version} is already migrated/rollback")
+            ensure
+              SequelRails::Migrations.migrate_up!
+            end
+          end
+        end
+      end
+    end
+  end
+
   describe 'db:rollback' do
     let(:version) { nil }
     let(:rake_task_call) do

spec/spec_helper.rb

@@ -5,6 +5,8 @@
 
 # Combustion initialization has to happen before loading rspec/rails
 Combustion.initialize! :sequel_rails
+# Load rake tasks
+Combustion::Application.load_tasks
 
 require 'rspec/rails'
 require 'ammeter/init'