Fix Struct#pretty_inspect error, add CI tasks for github

.github/workflows/main.yml

@@ -0,0 +1,36 @@
+name: CI
+
+on:
+  pull_request:
+    branches:
+      - main 
+  push:
+    branches:
+      - main 
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  main:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ruby:
+          - "3.1"
+          - "3.2"
+          - "3.3"
+          - "3.4"
+          - ruby-head
+    name: "Ruby ${{ matrix.ruby }}: ${{ matrix.task }}"
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: "${{ matrix.ruby }}"
+          bundler-cache: true
+      # install castxml for the importer tests
+      - run: sudo apt-get update && sudo apt-get install -y castxml
+      - run: bundle install
+      - run: bundle exec rake spec

.gitignore

@@ -10,7 +10,6 @@ Gemfile.lock
 
 # rspec failure tracking
 .rspec_status
-.rspec
 
 # apple files
 .DS_Store

.rspec

@@ -0,0 +1,3 @@
+--format documentation
+--color
+--require spec_helper

lib/ctypes/struct.rb

@@ -517,6 +517,7 @@ def pretty_print(q) # :nodoc:
           type.is_a?(CTypes::Pad)
         end
         q.seplist(fields, -> { q.breakable("") }) do |name, _|
+          names = name.is_a?(::Array) ? name : [name]
           names.each do |name|
             next if name.is_a?(CTypes::Pad)
             q.text(".#{name} = ")