6 files changed, 302 insertions, 0 deletions
diff --git a/spec/ruby/core/enumerator/product/each_spec.rb b/spec/ruby/core/enumerator/product/each_spec.rb
new file mode 100644
index 0000000000..cabeb9d93a
--- /dev/null
+++ b/spec/ruby/core/enumerator/product/each_spec.rb
@@ -0,0 +1,73 @@
+require_relative '../../../spec_helper'
+require_relative '../../enumerable/shared/enumeratorized'
+
+ruby_version_is "3.2" do
+  describe "Enumerator::Product#each" do
+    it_behaves_like :enumeratorized_with_origin_size, :each, Enumerator::Product.new([1, 2], [:a, :b])
+
+    it "yields each element of Cartesian product of enumerators" do
+      enum = Enumerator::Product.new([1, 2], [:a, :b])
+      acc = []
+      enum.each { |e| acc << e }
+      acc.should == [[1, :a], [1, :b], [2, :a], [2, :b]]
+    end
+
+    it "calls #each_entry method on enumerators" do
+      object1 = Object.new
+      def object1.each_entry
+        yield 1
+        yield 2
+      end
+
+      object2 = Object.new
+      def object2.each_entry
+        yield :a
+        yield :b
+      end
+
+      enum = Enumerator::Product.new(object1, object2)
+      acc = []
+      enum.each { |e| acc << e }
+      acc.should == [[1, :a], [1, :b], [2, :a], [2, :b]]
+    end
+
+    it "raises a NoMethodError if the object doesn't respond to #each_entry" do
+      -> {
+        Enumerator::Product.new(Object.new).each {}
+      }.should raise_error(NoMethodError, /undefined method [`']each_entry' for/)
+    end
+
+    it "returns enumerator if not given a block" do
+      enum = Enumerator::Product.new([1, 2], [:a, :b])
+      enum.each.should.kind_of?(Enumerator)
+
+      enum = Enumerator::Product.new([1, 2], [:a, :b])
+      enum.each.to_a.should == [[1, :a], [1, :b], [2, :a], [2, :b]]
+    end
+
+    it "returns self if given a block" do
+      enum = Enumerator::Product.new([1, 2], [:a, :b])
+      enum.each {}.should.equal?(enum)
+    end
+
+    it "doesn't accept arguments" do
+      Enumerator::Product.instance_method(:each).arity.should == 0
+    end
+
+    it "yields each element to a block that takes multiple arguments" do
+      enum = Enumerator::Product.new([1, 2], [:a, :b])
+
+      acc = []
+      enum.each { |x, y| acc << x }
+      acc.should == [1, 1, 2, 2]
+
+      acc = []
+      enum.each { |x, y| acc << y }
+      acc.should == [:a, :b, :a, :b]
+
+      acc = []
+      enum.each { |x, y, z| acc << z }
+      acc.should == [nil, nil, nil, nil]
+    end
+  end
+end
diff --git a/spec/ruby/core/enumerator/product/initialize_copy_spec.rb b/spec/ruby/core/enumerator/product/initialize_copy_spec.rb
new file mode 100644
index 0000000000..46e8421322
--- /dev/null
+++ b/spec/ruby/core/enumerator/product/initialize_copy_spec.rb
@@ -0,0 +1,54 @@
+require_relative '../../../spec_helper'
+
+ruby_version_is "3.2" do
+  describe "Enumerator::Product#initialize_copy" do
+    it "replaces content of the receiver with content of the other object" do
+      enum = Enumerator::Product.new([true, false])
+      enum2 = Enumerator::Product.new([1, 2], [:a, :b])
+
+      enum.send(:initialize_copy, enum2)
+      enum.each.to_a.should == [[1, :a], [1, :b], [2, :a], [2, :b]]
+    end
+
+    it "returns self" do
+      enum = Enumerator::Product.new([true, false])
+      enum2 = Enumerator::Product.new([1, 2], [:a, :b])
+
+      enum.send(:initialize_copy, enum2).should.equal?(enum)
+    end
+
+    it "is a private method" do
+      Enumerator::Product.should have_private_instance_method(:initialize_copy, false)
+    end
+
+    it "does nothing if the argument is the same as the receiver" do
+      enum = Enumerator::Product.new(1..2)
+      enum.send(:initialize_copy, enum).should.equal?(enum)
+
+      enum.freeze
+      enum.send(:initialize_copy, enum).should.equal?(enum)
+    end
+
+    it "raises FrozenError if the receiver is frozen" do
+      enum = Enumerator::Product.new(1..2)
+      enum2 = Enumerator::Product.new(3..4)
+
+      -> { enum.freeze.send(:initialize_copy, enum2) }.should raise_error(FrozenError)
+    end
+
+    it "raises TypeError if the objects are of different class" do
+      enum = Enumerator::Product.new(1..2)
+      enum2 = Class.new(Enumerator::Product).new(3..4)
+
+      -> { enum.send(:initialize_copy, enum2) }.should raise_error(TypeError, 'initialize_copy should take same class object')
+      -> { enum2.send(:initialize_copy, enum) }.should raise_error(TypeError, 'initialize_copy should take same class object')
+    end
+
+    it "raises ArgumentError if the argument is not initialized yet" do
+      enum = Enumerator::Product.new(1..2)
+      enum2 = Enumerator::Product.allocate
+
+      -> { enum.send(:initialize_copy, enum2) }.should raise_error(ArgumentError, 'uninitialized product')
+    end
+  end
+end
diff --git a/spec/ruby/core/enumerator/product/initialize_spec.rb b/spec/ruby/core/enumerator/product/initialize_spec.rb
new file mode 100644
index 0000000000..4b60564240
--- /dev/null
+++ b/spec/ruby/core/enumerator/product/initialize_spec.rb
@@ -0,0 +1,33 @@
+require_relative '../../../spec_helper'
+
+ruby_version_is "3.2" do
+  describe "Enumerator::Product#initialize" do
+    before :each do
+      @uninitialized = Enumerator::Product.allocate
+    end
+
+    it "is a private method" do
+      Enumerator::Product.should have_private_instance_method(:initialize, false)
+    end
+
+    it "returns self" do
+      @uninitialized.send(:initialize).should equal(@uninitialized)
+    end
+
+    it "accepts many arguments" do
+      @uninitialized.send(:initialize, 0..1, 2..3, 4..5).should equal(@uninitialized)
+    end
+
+    it "accepts arguments that are not Enumerable nor responding to :each_entry" do
+      @uninitialized.send(:initialize, Object.new).should equal(@uninitialized)
+    end
+
+    describe "on frozen instance" do
+      it "raises a FrozenError" do
+        -> {
+          @uninitialized.freeze.send(:initialize, 0..1)
+        }.should raise_error(FrozenError)
+      end
+    end
+  end
+end
diff --git a/spec/ruby/core/enumerator/product/inspect_spec.rb b/spec/ruby/core/enumerator/product/inspect_spec.rb
new file mode 100644
index 0000000000..1ea8e9c49b
--- /dev/null
+++ b/spec/ruby/core/enumerator/product/inspect_spec.rb
@@ -0,0 +1,22 @@
+require_relative '../../../spec_helper'
+
+ruby_version_is "3.2" do
+  describe "Enumerator::Product#inspect" do
+    it "returns a String including enumerators" do
+      enum = Enumerator::Product.new([1, 2], [:a, :b])
+      enum.inspect.should == "#<Enumerator::Product: [[1, 2], [:a, :b]]>"
+    end
+
+    it "represents a recursive element with '[...]'" do
+      enum = [1, 2]
+      enum_recursive = Enumerator::Product.new(enum)
+
+      enum << enum_recursive
+      enum_recursive.inspect.should == "#<Enumerator::Product: [[1, 2, #<Enumerator::Product: ...>]]>"
+    end
+
+    it "returns a not initialized representation if #initialized is not called yet" do
+      Enumerator::Product.allocate.inspect.should == "#<Enumerator::Product: uninitialized>"
+    end
+  end
+end
diff --git a/spec/ruby/core/enumerator/product/rewind_spec.rb b/spec/ruby/core/enumerator/product/rewind_spec.rb
new file mode 100644
index 0000000000..e8ee730239
--- /dev/null
+++ b/spec/ruby/core/enumerator/product/rewind_spec.rb
@@ -0,0 +1,64 @@
+require_relative '../../../spec_helper'
+
+ruby_version_is "3.2" do
+  describe "Enumerator::Product#rewind" do
+    before :each do
+      @enum = Enumerator::Product.new([1, 2].each.to_enum, [:a, :b].each.to_enum)
+    end
+
+    it "resets the enumerator to its initial state" do
+      @enum.each.to_a.should == [[1, :a], [1, :b], [2, :a], [2, :b]]
+      @enum.rewind
+      @enum.each.to_a.should == [[1, :a], [1, :b], [2, :a], [2, :b]]
+    end
+
+    it "returns self" do
+      @enum.rewind.should.equal? @enum
+    end
+
+    it "has no effect on a new enumerator" do
+      @enum.rewind
+      @enum.each.to_a.should == [[1, :a], [1, :b], [2, :a], [2, :b]]
+    end
+
+    it "has no effect if called multiple, consecutive times" do
+      @enum.each.to_a.should == [[1, :a], [1, :b], [2, :a], [2, :b]]
+      @enum.rewind
+      @enum.rewind
+      @enum.each.to_a.should == [[1, :a], [1, :b], [2, :a], [2, :b]]
+    end
+
+    it "calls the enclosed object's rewind method if one exists" do
+      obj = mock('rewinder')
+      enum = Enumerator::Product.new(obj.to_enum)
+
+      obj.should_receive(:rewind)
+      enum.rewind
+    end
+
+    it "does nothing if the object doesn't have a #rewind method" do
+      obj = mock('rewinder')
+      enum = Enumerator::Product.new(obj.to_enum)
+
+      enum.rewind.should == enum
+    end
+
+    it "calls a rewind method on each enumerable in direct order" do
+      ScratchPad.record []
+
+      object1 = Object.new
+      def object1.rewind; ScratchPad << :object1; end
+
+      object2 = Object.new
+      def object2.rewind; ScratchPad << :object2; end
+
+      object3 = Object.new
+      def object3.rewind; ScratchPad << :object3; end
+
+      enum = Enumerator::Product.new(object1, object2, object3)
+      enum.rewind
+
+      ScratchPad.recorded.should == [:object1, :object2, :object3]
+    end
+  end
+end
diff --git a/spec/ruby/core/enumerator/product/size_spec.rb b/spec/ruby/core/enumerator/product/size_spec.rb
new file mode 100644
index 0000000000..46958b1a22
--- /dev/null
+++ b/spec/ruby/core/enumerator/product/size_spec.rb
@@ -0,0 +1,56 @@
+require_relative '../../../spec_helper'
+
+ruby_version_is "3.2" do
+  describe "Enumerator::Product#size" do
+    it "returns the total size of the enumerator product calculated by multiplying the sizes of enumerables in the product" do
+      product = Enumerator::Product.new(1..2, 1..3, 1..4)
+      product.size.should == 24 # 2 * 3 * 4
+    end
+
+    it "returns nil if any enumerable reports its size as nil" do
+      enum = Object.new
+      def enum.size; nil; end
+
+      product = Enumerator::Product.new(1..2, enum)
+      product.size.should == nil
+    end
+
+    it "returns Float::INFINITY if any enumerable reports its size as Float::INFINITY" do
+      enum = Object.new
+      def enum.size; Float::INFINITY; end
+
+      product = Enumerator::Product.new(1..2, enum)
+      product.size.should == Float::INFINITY
+    end
+
+    it "returns nil if any enumerable reports its size as Float::NAN" do
+      enum = Object.new
+      def enum.size; Float::NAN; end
+
+      product = Enumerator::Product.new(1..2, enum)
+      product.size.should == nil
+    end
+
+    it "returns nil if any enumerable doesn't respond to #size" do
+      enum = Object.new
+      product = Enumerator::Product.new(1..2, enum)
+      product.size.should == nil
+    end
+
+    it "returns nil if any enumerable reports a not-convertible to Integer" do
+      enum = Object.new
+      def enum.size; :symbol; end
+
+      product = Enumerator::Product.new(1..2, enum)
+      product.size.should == nil
+    end
+
+    it "returns nil if any enumerable reports a non-Integer but convertible to Integer size" do
+      enum = Object.new
+      def enum.size; 1.0; end
+
+      product = Enumerator::Product.new(1..2, enum)
+      product.size.should == nil
+    end
+  end
+end