Merge pull request #1017 from AI-Mozi/add_tests_for_Enumerator_product

Add spec for `Enumerator#product`

core/enumerator/product_spec.rb

@@ -0,0 +1,22 @@
+require_relative '../../spec_helper'
+
+ruby_version_is "3.2" do
+  describe "Enumerator.product" do
+    it "creates an infinite enumerator" do
+      enum = Enumerator.product(1.., ["A", "B"])
+      enum.take(5).should == [[1, "A"], [1, "B"], [2, "A"], [2, "B"], [3, "A"]]
+    end
+
+    it "accepts a block" do
+      elems = []
+      enum = Enumerator.product(1..2, ["X", "Y"]) { elems << _1 }
+
+      elems.should == [[1, "X"], [1, "Y"], [2, "X"], [2, "Y"]]
+    end
+
+    it "accepts infinite enumerator and uknown enumerator" do
+      enum = Enumerator.product(1.., Enumerator.new { |y| y << "X" << "Y" })
+      enum.take(4).should == [[1, "X"], [1, "Y"], [2, "X"], [2, "Y"]]
+    end
+  end
+end