#171

backend/app/controllers/posts_controller.rb

@@ -177,8 +177,8 @@ class PostsController < ApplicationController
     merge = bool?(:merge)
     return head :bad_request if force && merge
 
-    base_version_no = nil
-    base_version_no = parse_base_version_no unless force
+    base_version_no = parse_base_version_no
+    return head :bad_request if !(force) && !(base_version_no)
 
     title = params[:title].presence
     tag_names = params[:tags].to_s.split
@@ -442,9 +442,11 @@ class PostsController < ApplicationController
 
   def parse_base_version_no
     version_no = Integer(params[:base_version_no], exception: false)
-    raise ArgumentError, 'base_version_no は必須です．' unless version_no&.positive?
-
-    version_no
+    if version_no&.positive?
+      version_no
+    else
+      nil
+    end
   end
 
   def post_snapshot_from_version version

backend/app/services/version_recorder.rb

@@ -16,7 +16,7 @@ class VersionRecorder
       @record = record_class.unscoped.lock.find(@record.id)
       latest = latest_version
 
-      validate_version_sequence! latest
+      validate_version_sequence!(latest)
 
       attrs = snapshot_attributes
 
@@ -27,7 +27,7 @@ class VersionRecorder
       version = version_class.create!(
           base_attributes(latest).merge(record_key => @record).merge(attrs))
 
-      update_record_version_no! version.version_no
+      update_record_version_no!(version.version_no)
 
       version
     end
@@ -47,7 +47,7 @@ class VersionRecorder
   end
 
   def update_record_version_no! version_no
-    @record.update_columns version_no: version_no
+    @record.update_columns(version_no:)
     @record.version_no = version_no
   end