Add tasks to check for pending/running migrations

lib/sequent/migrations/versions.rb

@@ -24,6 +24,18 @@ def self.migration_sql
               where(status: [MIGRATE_ONLINE_RUNNING, MIGRATE_ONLINE_FINISHED, MIGRATE_OFFLINE_RUNNING])
             }
 
+      def self.current_version
+        done.latest_version || 0
+      end
+
+      def self.running_version
+        running.latest_version
+      end
+
+      def self.latest_version
+        order('version desc').limit(1).first&.version
+      end
+
       def self.start_online!(new_version)
         create!(version: new_version, status: MIGRATE_ONLINE_RUNNING)
       rescue ActiveRecord::RecordNotUnique

lib/sequent/migrations/view_schema.rb

@@ -113,7 +113,7 @@ def initialize(db_config:)
       ##
       # Returns the current version from the database
       def current_version
-        Versions.done.order('version desc').limit(1).first&.version || 0
+        Versions.current_version
       end
 
       ##

lib/sequent/rake/migration_tasks.rb

@@ -31,6 +31,11 @@ def register_tasks!
           EOS
           task init: :set_env_var
 
+          task connect_to_db: ['sequent:init', :init] do
+            ensure_sequent_env_set!
+            Sequent::Support::Database.connect!(@env)
+          end
+
           namespace :db do
             desc 'Creates the database and initializes the event_store schema for the current env'
             task create: ['sequent:init'] do
@@ -91,12 +96,26 @@ def register_tasks!
             task :init
 
             desc 'Prints the current version in the database'
-            task current_version: ['sequent:init', :init] do
-              ensure_sequent_env_set!
+            task current_version: [:connect_to_db] do
+              puts "Current version in the database is: #{Sequent::Migrations::Versions.current_version}"
+            end
 
-              Sequent::Support::Database.connect!(@env)
+            desc 'Returns whether a migration is currently running'
+            task has_running_migrations: [:connect_to_db] do
+              if Sequent::Migrations::Versions.running.any?
+                puts "Migration is running, current version: #{Sequent::Migrations::Versions.current_version}, target version #{Sequent::Migrations::Versions.running_version}"
+              else
+                puts 'No running migrations'
+              end
+            end
 
-              puts "Current version in the database is: #{Sequent::Migrations::Versions.maximum(:version)}"
+            desc 'Returns whether a migration is pending'
+            task has_pending_migrations: [:connect_to_db] do
+              if Sequent.new_version != Sequent::Migrations::Versions.current_version
+                puts "Migration is pending, current version: #{Sequent::Migrations::Versions.current_version}, pending version: #{Sequent.new_version}"
+              else
+                puts 'No pending migrations'
+              end
             end
 
             desc <<~EOS