1 files changed, 40 insertions, 0 deletions
diff --git a/spec/ruby/core/struct/keyword_init_spec.rb b/spec/ruby/core/struct/keyword_init_spec.rb
new file mode 100644
index 0000000000..8de4c14351
--- /dev/null
+++ b/spec/ruby/core/struct/keyword_init_spec.rb
@@ -0,0 +1,40 @@
+require_relative '../../spec_helper'
+
+ruby_version_is "3.1" do
+  # See https://bugs.ruby-lang.org/issues/18008
+  describe "StructClass#keyword_init?" do
+    it "returns true for a struct that accepts keyword arguments to initialize" do
+      struct = Struct.new(:arg, keyword_init: true)
+      struct.keyword_init?.should be_true
+    end
+
+    it "returns false for a struct that does not accept keyword arguments to initialize" do
+      struct = Struct.new(:arg, keyword_init: false)
+      struct.keyword_init?.should be_false
+    end
+
+    it "returns nil for a struct that did not explicitly specify keyword_init" do
+      struct = Struct.new(:arg)
+      struct.keyword_init?.should be_nil
+    end
+
+    it "returns nil for a struct that does specify keyword_init to be nil" do
+      struct = Struct.new(:arg, keyword_init: nil)
+      struct.keyword_init?.should be_nil
+    end
+
+    it "returns true for any truthy value, not just for true" do
+      struct = Struct.new(:arg, keyword_init: 1)
+      struct.keyword_init?.should be_true
+
+      struct = Struct.new(:arg, keyword_init: "")
+      struct.keyword_init?.should be_true
+
+      struct = Struct.new(:arg, keyword_init: [])
+      struct.keyword_init?.should be_true
+
+      struct = Struct.new(:arg, keyword_init: {})
+      struct.keyword_init?.should be_true
+    end
+  end
+end