Rakefile in path_tree-1.0.12 vs Rakefile in path_tree-1.1.0

@@ -1,20 +1,40 @@
 require 'bundler/gem_tasks'
+require 'bundler/setup'  # constrain rake version
+
+# Note: if you get this error: "Bundler could not find compatible versions for gem ..."
+# try deleting Gemfile.lock (usually happens when switching branches).
+
+task default: :appraise_all
+
+# This is slightly different from 'appraisal COMMAND' because it continues even if a definition fails.
+desc "Run rspecs for all appraisals"
+task :appraise_all do
+  success_map = {}
+  `bundle exec appraisal list`.lines.map(&:chomp).each do |appraise_def|
+     success = system('appraisal', appraise_def, 'rspec', 'spec')
+     success_map[appraise_def] = success
+  end
+  puts "\n===== Test Summary ====="
+  success_map.each do |appraise_def, success|
+    puts "#{appraise_def}: #{success ? 'no failures (but check pending)' : 'failed'}"
+  end
+end