1 files changed, 34 insertions, 0 deletions
diff --git a/spec/ruby/core/exception/frozen_error_spec.rb b/spec/ruby/core/exception/frozen_error_spec.rb
new file mode 100644
index 0000000000..7b356253c4
--- /dev/null
+++ b/spec/ruby/core/exception/frozen_error_spec.rb
@@ -0,0 +1,34 @@
+require_relative '../../spec_helper'
+
+describe "FrozenError" do
+  ruby_version_is "2.5" do
+    it "is a subclass of RuntimeError" do
+      RuntimeError.should be_ancestor_of(FrozenError)
+    end
+  end
+end
+
+describe "FrozenError.new" do
+  ruby_version_is "2.7" do
+    it "should take optional receiver argument" do
+      o = Object.new
+      FrozenError.new("msg", o).receiver.should equal(o)
+    end
+  end
+end
+
+describe "FrozenError#receiver" do
+  ruby_version_is "2.7" do
+    it "should return frozen object that modification was attempted on" do
+      o = Object.new.freeze
+      begin
+        def o.x; end
+      rescue => e
+        e.should be_kind_of(FrozenError)
+        e.receiver.should equal(o)
+      else
+        raise
+      end
+    end
+  end
+end