Use GitHub Actions for CI

.github/workflows/test.yml

@@ -0,0 +1,24 @@
+name: build
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    name: build (${{ matrix.ruby }} / ${{ matrix.os }})
+    strategy:
+      matrix:
+        ruby: [ 3.0, 2.7, head ]
+        os: [ ubuntu-latest, macos-latest ]
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@master
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby }}
+    - name: Install dependencies
+      run: |
+        gem install bundler --no-document
+        bundle install
+    - name: Run test
+      run: rake test

.gitignore

@@ -6,3 +6,4 @@
 /pkg/
 /spec/reports/
 /tmp/
+/Gemfile.lock

lib/pp.rb

@@ -236,7 +236,7 @@ def seplist(list, sep=nil, iter_method=:each) # :yield: element
         else
           sep.call
         end
-        yield(*v, **{})
+        RUBY_VERSION >= "3.0" ? yield(*v, **{}) : yield(*v)
       }
     end
 

pp.gemspec

@@ -7,9 +7,10 @@ Gem::Specification.new do |spec|
   spec.summary       = %q{Provides a PrettyPrinter for Ruby objects}
   spec.description   = %q{Provides a PrettyPrinter for Ruby objects}
   spec.homepage      = "https://github.com/ruby/pp"
-  spec.required_ruby_version = Gem::Requirement.new(">= 2.3.0")
   spec.licenses      = ["Ruby", "BSD-2-Clause"]
 
+  spec.required_ruby_version = Gem::Requirement.new(">= 2.7.0")
+
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = spec.homepage