only build container for the main branch

.gitea/workflows/ci.yaml

@@ -38,11 +38,11 @@ jobs:
           ruby-version: '3.4'
           bundler-cache: true
 
-      - run: bundle exec rspec
+      - run: bundle exec rake
-
 
   release-image:
     needs: test
+    if: github.ref == 'refs/heads/main'
     runs-on: ubuntu-latest
     container:
       image: catthehacker/ubuntu:act-latest

lib/sensitive.rb

@@ -10,7 +10,7 @@ class Sensitive
   end
 
   def mask(v)
-    "".concat(v[0, @head], @ch * (v.length - (@head + @tail)), v[-@tail, @tail])
+    String.new.concat(v[0, @head], @ch * (v.length - (@head + @tail)), v[-@tail, @tail])
   end
 
   def unwrap