Import set 1.0.0

- SortedSet has been removed for dependency and performance reasons.
- Set#join is added as a shorthand for `.to_a.join`.
- Set#<=> is added.

https://github.com/ruby/set/blob/v1.0.0/CHANGELOG.md

3 files changed, 53 insertions, 0 deletions

diff --git a/test/fixtures/fake_sorted_set_gem/sorted_set.rb b/test/fixtures/fake_sorted_set_gem/sorted_set.rb
new file mode 100644
index 0000000000..02c9721fa2
--- /dev/null
+++ b/test/fixtures/fake_sorted_set_gem/sorted_set.rb
@@ -0,0 +1,3 @@
+class SortedSet
+  # ...
+end
diff --git a/test/test_set.rb b/test/test_set.rb
index 05431e4c63..e62f30d852 100644
--- a/test/test_set.rb
+++ b/test/test_set.rb
@@ -759,6 +759,11 @@ class TC_Set < Test::Unit::TestCase
     assert_equal Set[1,2,3], set1
   end if Kernel.instance_method(:initialize_clone).arity != 1
 
+  def test_join
+    assert_equal('123', Set[1, 2, 3].join)
+    assert_equal('1 & 2 & 3', Set[1, 2, 3].join(' & '))
+  end
+
   def test_inspect
     set1 = Set[1, 2]
     assert_equal('#<Set: {1, 2}>', set1.inspect)
diff --git a/test/test_sorted_set.rb b/test/test_sorted_set.rb
new file mode 100644
index 0000000000..1ac6ee929a
--- /dev/null
+++ b/test/test_sorted_set.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: false
+require 'test/unit'
+require 'set'
+
+class TC_SortedSet < Test::Unit::TestCase
+  def base_dir
+    "#{__dir__}/../lib"
+  end
+
+  def assert_runs(ruby, options: nil)
+    options = ['-I', base_dir, *options]
+    r = system(RbConfig.ruby, *options, '-e', ruby)
+    assert(r)
+  end
+
+  def test_error
+    assert_runs <<~RUBY
+      require "set"
+
+      r = begin
+        puts SortedSet.new
+      rescue Exception => e
+        e.message
+      end
+      raise r unless r.match? /has been extracted/
+    RUBY
+  end
+
+  def test_ok_with_gem
+    assert_runs <<~RUBY, options: ['-I', "#{__dir__}/fixtures/fake_sorted_set_gem"]
+      require "set"
+
+      var = SortedSet.new.to_s
+    RUBY
+  end
+
+  def test_ok_require
+    assert_runs <<~RUBY, options: ['-I', "#{__dir__}/fixtures/fake_sorted_set_gem"]
+      require "set"
+      require "sorted_set"
+
+      var = SortedSet.new.to_s
+    RUBY
+  end
+end