1 files changed, 112 insertions, 0 deletions
diff --git a/test/ruby/weakkeymap.rb b/test/ruby/weakkeymap.rb
new file mode 100644
index 0000000000..20bfe5ec2c
--- /dev/null
+++ b/test/ruby/weakkeymap.rb
@@ -0,0 +1,112 @@
+# frozen_string_literal: false
+require 'test/unit'
+
+class TestWeakKeyMap < Test::Unit::TestCase
+  def setup
+    @wm = ObjectSpace::WeakKeyMap.new
+  end
+
+  def test_map
+    x = Object.new
+    k = "foo"
+    @wm[k] = x
+    assert_same(x, @wm[k])
+    assert_same(x, @wm["FOO".downcase])
+  end
+
+  def test_aset_const
+    x = Object.new
+    assert_raise(ArgumentError) { @wm[true] = x }
+    assert_raise(ArgumentError) { @wm[false] = x }
+    assert_raise(ArgumentError) { @wm[nil] = x }
+    assert_raise(ArgumentError) { @wm[42] = x }
+    assert_raise(ArgumentError) { @wm[2**128] = x }
+    assert_raise(ArgumentError) { @wm[1.23] = x }
+    assert_raise(ArgumentError) { @wm[:foo] = x }
+    assert_raise(ArgumentError) { @wm["foo#{rand}".to_sym] = x }
+  end
+
+  def test_getkey
+    k = "foo"
+    @wm[k] = true
+    assert_same(k, @wm.getkey("FOO".downcase))
+  end
+
+  def test_key?
+    1.times do
+      assert_weak_include(:key?, "foo")
+    end
+    GC.start
+    assert_not_send([@wm, :key?, "FOO".downcase])
+  end
+
+  def test_clear
+    k = "foo"
+    @wm[k] = true
+    assert @wm[k]
+    assert_same @wm, @wm.clear
+    refute @wm[k]
+  end
+
+  def test_inspect
+    x = Object.new
+    k = Object.new
+    @wm[k] = x
+    assert_match(/\A\#<#{@wm.class.name}:[\dxa-f]+ size=\d+>\z/, @wm.inspect)
+
+    1000.times do |i|
+      @wm[i.to_s] = Object.new
+      @wm.inspect
+    end
+    assert_match(/\A\#<#{@wm.class.name}:[\dxa-f]+ size=\d+>\z/, @wm.inspect)
+  end
+
+  def test_no_hash_method
+    k = BasicObject.new
+    assert_raise NoMethodError do
+      @wm[k] = 42
+    end
+  end
+
+  def test_frozen_object
+    o = Object.new.freeze
+    assert_nothing_raised(FrozenError) {@wm[o] = 'foo'}
+    assert_nothing_raised(FrozenError) {@wm['foo'] = o}
+  end
+
+  def test_inconsistent_hash_key
+    assert_no_memory_leak [], '', <<~RUBY
+      class BadHash
+        def initialize
+          @hash = 0
+        end
+
+        def hash
+          @hash += 1
+        end
+      end
+
+      k = BadHash.new
+      wm = ObjectSpace::WeakKeyMap.new
+
+      100_000.times do |i|
+        wm[k] = i
+      end
+    RUBY
+  end
+
+  private
+
+  def assert_weak_include(m, k, n = 100)
+    if n > 0
+      return assert_weak_include(m, k, n-1)
+    end
+    1.times do
+      x = Object.new
+      @wm[k] = x
+      assert_send([@wm, m, k])
+      assert_send([@wm, m, "FOO".downcase])
+      x = Object.new
+    end
+  end
+end