First version of migration system

Author: madAle

lib/fancybox2/migrations/base.rb

@@ -0,0 +1,18 @@
+module Fancybox2
+  module Migrations
+    class Base
+
+      attr_reader :name, :version
+
+      def initialize(name)
+        @name = name
+
+        @version = Runner.extract_and_validate_version_from name
+      end
+
+      def call(up_or_down = :up)
+        send up_or_down
+      end
+    end
+  end
+end

lib/fancybox2/migrations/exceptions.rb

@@ -0,0 +1,13 @@
+module Fancybox2
+  module Migrations
+    module Exceptions
+
+      class FileNameError < StandardError
+        def initialize(message = nil)
+          message = message || 'One of the provided migrations file has an invalid name'
+          super(message)
+        end
+      end
+    end
+  end
+end

lib/fancybox2/migrations/runner.rb

@@ -0,0 +1,71 @@
+module Fancybox2
+  module Migrations
+    class Runner
+      include Exceptions
+
+      VERSION_REGEXP = /^(\d{14})/.freeze
+
+      class << self
+
+        def extract_and_validate_version_from(migration_name)
+          version = migration_name.to_s.scan(VERSION_REGEXP).flatten.first
+          unless version
+            raise ArgumentError, 'migration version must be a 14 digits integer'
+          end
+
+          version.to_i
+        end
+      end
+
+      attr_reader :files_path, :current_version, :migrations
+
+      def initialize(files_path, current_version = nil)
+        @files_path = files_path
+        if current_version
+          @current_version = self.class.extract_and_validate_version_from current_version
+        end
+
+        load_migrations
+      end
+
+      def run(from: nil, to: nil)
+        # Select migrations to run
+        to_run = migrations_to_run from, to
+      end
+
+      def load_migrations
+        # Load files from files_path and create classes
+        @migrations = Dir[File.join(File.expand_path(files_path), '**', '*.rb')].sort.map do |f_path|
+          migration_name = File.basename(f_path)
+          klass = Class.new(Base)
+          klass.class_eval(File.read(f_path), f_path)
+          klass.freeze
+          klass.new migration_name
+        end
+      end
+
+      # Select migrations to run depending on direction
+      # :up selects only migration with a version greater than current_version
+      # :down selects migrations with a version lower_or_equal_to current_version
+      def migrations_to_run(from, to)
+        selected = []
+        @migrations.each do |m|
+          # Break if we already arrived to "from" migration
+          break if (from > to) && (m.version > from)
+          # Break if we already arrived to "to" migration
+          break if (from < to) && (m.version > to)
+          # Skip until we arrive to "from" migration
+          next if (from < to) && (m.version < from)
+
+          if m.version <= from
+            selected.prepend m
+          else
+            selected.append m
+          end
+        end
+
+        selected
+      end
+    end
+  end
+end

lib/fancybox2/migrations/test/20200119151500_first.rb

@@ -0,0 +1,7 @@
+def up
+  puts "2020 UP"
+end
+
+def down
+  puts "2020 DOWN"
+end

lib/fancybox2/migrations/test/20210119151500_first.rb

@@ -0,0 +1,7 @@
+def up
+  puts "2021 UP"
+end
+
+def down
+  puts "2021 DOWN"
+end

lib/fancybox2/migrations/test/20220119151500_first.rb

@@ -0,0 +1,7 @@
+def up
+  puts "2022 UP"
+end
+
+def down
+  puts "2022 DOWN"
+end

lib/fancybox2/module/base.rb

@@ -87,13 +87,10 @@ def on_configs(packet = nil, &block)
           @on_configs = block
           return
         end
-        begin
-          cfg = packet.payload
-          if cfg && cfg.is_a?(Hash) && cfg['configs']
-            self.configs.merge! cfg['configs']
-          end
-        rescue JSON::ParserError
-          logger.debug 'on_configs: failed parsing packet as JSON'
+
+        cfg = packet.payload
+        if cfg && cfg.is_a?(Hash) && cfg['configs']
+          self.configs.merge! cfg['configs']
         end
 
         @on_configs.call(packet) if @on_configs