3-start: renamed major,minor,patch to just start

lib/release/start.rb

@@ -0,0 +1,61 @@
+require_relative './base'
+
+module Release
+
+  class Start < Release::Base
+    def valid?
+      argv.size == 3 or argv.size == 4
+    end
+
+    def help
+      "release start (major|minor|patch) [from] version"
+    end
+
+    def execute
+      case argv.size
+      when 3
+        subcommand, level, version = *argv
+      when 4
+        subcommand, level, verb, version = *argv
+      end
+
+      validate_version_format version
+
+      validate_current_branch_master
+      git_pull current_branch
+
+      validate_version_exists version
+
+      numbers = version.split('.').map { |x| x.to_i }
+      case level
+      when 'major'
+        new_version = "#{numbers[0]+1}.0.0"
+      when 'minor'
+        new_version = "#{numbers[0]}.#{numbers[1]+1}.0"
+      when 'patch'
+        new_version = "#{numbers[0]}.#{numbers[1]}.#{numbers[2]+1}"
+      else
+        error "unknow release level: #{level}"
+      end
+
+      validate_version_does_not_exist new_version
+      validate_release_branch_does_not_exist(release_branch_from_version(new_version))
+
+      git_local_branch_create release_branch_from_version(new_version), release_tag_from_version(version)
+
+      git_push release_branch_from_version(new_version)
+    end
+
+    private
+
+    def subcommand_name
+      error "override"
+    end
+
+    def increment_version (version)
+      error "override"
+    end
+
+  end
+
+end