1 files changed, 74 insertions, 0 deletions
diff --git a/spec/ruby/core/struct/initialize_spec.rb b/spec/ruby/core/struct/initialize_spec.rb
new file mode 100644
index 0000000000..c824f52e13
--- /dev/null
+++ b/spec/ruby/core/struct/initialize_spec.rb
@@ -0,0 +1,74 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Struct#initialize" do
+
+  it "is private" do
+    StructClasses::Car.private_instance_methods(true).should.include?(:initialize)
+  end
+
+  it 'allows valid Ruby method names for members' do
+    valid_method_names = [
+      :method1,
+      :method_1,
+      :method_1?,
+      :method_1!,
+      :a_method
+    ]
+    valid_method_names.each do |method_name|
+      klass = Struct.new(method_name)
+      instance = klass.new(:value)
+      instance.send(method_name).should == :value
+      writer_method = "#{method_name}=".to_sym
+      result = instance.send(writer_method, :new_value)
+      result.should == :new_value
+      instance.send(method_name).should == :new_value
+    end
+  end
+
+  it "does nothing when passed a set of fields equal to self" do
+    car = same_car = StructClasses::Car.new("Honda", "Accord", "1998")
+    car.instance_eval { initialize("Honda", "Accord", "1998") }
+    car.should == same_car
+  end
+
+  it "explicitly sets instance variables to nil when args not provided to initialize" do
+    car = StructClasses::Honda.new
+    car.make.should == nil # still nil despite override in Honda#initialize b/c of super order
+  end
+
+  it "can be overridden" do
+    StructClasses::SubclassX.new(:y).new.key.should == :value
+  end
+
+  it "can be initialized with keyword arguments" do
+    positional_args = StructClasses::Ruby.new("3.2", "OS")
+    keyword_args = StructClasses::Ruby.new(version: "3.2", platform: "OS")
+
+    positional_args.version.should == keyword_args.version
+    positional_args.platform.should == keyword_args.platform
+  end
+
+  it "accepts positional arguments with empty keyword arguments" do
+    data = StructClasses::Single.new(42, **{})
+
+    data.value.should == 42
+
+    data = StructClasses::Ruby.new("3.2", "OS", **{})
+
+    data.version.should == "3.2"
+    data.platform.should == "OS"
+  end
+
+  it "can be called via delegated ... from a prepended module" do
+    wrapper = Module.new do
+      def initialize(...)
+        super(...)
+      end
+    end
+
+    klass = Class.new(Struct.new(:a)) { prepend wrapper }
+    s = klass.new("x")
+    s.a.should == "x"
+  end
+end