1 files changed, 57 insertions, 52 deletions

diff --git a/spec/ruby/core/enumerator/new_spec.rb b/spec/ruby/core/enumerator/new_spec.rb
index 100edc8455..eb6c13759e 100644
--- a/spec/ruby/core/enumerator/new_spec.rb
+++ b/spec/ruby/core/enumerator/new_spec.rb
@@ -1,42 +1,10 @@
 require_relative '../../spec_helper'
 
 describe "Enumerator.new" do
-  it "creates a new custom enumerator with the given object, iterator and arguments" do
-    enum = Enumerator.new(1, :upto, 3)
-    enum.should be_an_instance_of(Enumerator)
-  end
-
-  it "creates a new custom enumerator that responds to #each" do
-    enum = Enumerator.new(1, :upto, 3)
-    enum.respond_to?(:each).should == true
-  end
-
-  it "creates a new custom enumerator that runs correctly" do
-    Enumerator.new(1, :upto, 3).map{|x|x}.should == [1,2,3]
-  end
-
-  it "aliases the second argument to :each" do
-    Enumerator.new(1..2).to_a.should == Enumerator.new(1..2, :each).to_a
-  end
-
-  it "doesn't check for the presence of the iterator method" do
-    Enumerator.new(nil).should be_an_instance_of(Enumerator)
-  end
-
-  it "uses the latest define iterator method" do
-    class StrangeEach
-      def each
-        yield :foo
-      end
+  context "no block given" do
+    it "raises" do
+      -> { Enumerator.new(1, :upto, 3) }.should.raise(ArgumentError)
     end
-    enum = Enumerator.new(StrangeEach.new)
-    enum.to_a.should == [:foo]
-    class StrangeEach
-      def each
-        yield :bar
-      end
-    end
-    enum.to_a.should == [:bar]
   end
 
   context "when passed a block" do
@@ -66,45 +34,82 @@ describe "Enumerator.new" do
       enum.take(3).should == [1, 2, 3]
     end
 
-    ruby_version_is "2.7" do
-      it "defines iteration with block, yielder argument and treating it as a proc" do
-        enum = Enumerator.new do |yielder|
-          "a\nb\nc".each_line(&yielder)
-        end
-
-        enum.to_a.should == ["a\n", "b\n", "c"]
+    it "defines iteration with block, yielder argument and treating it as a proc" do
+      enum = Enumerator.new do |yielder|
+        "a\nb\nc".each_line(&yielder)
       end
+
+      enum.to_a.should == ["a\n", "b\n", "c"]
     end
 
-    describe 'yielded values' do
-      it 'handles yield arguments properly' do
+    describe '#yield' do
+      it 'accepts a single argument' do
         Enumerator.new { |y| y.yield(1) }.to_a.should == [1]
         Enumerator.new { |y| y.yield(1) }.first.should == 1
+      end
 
-        Enumerator.new { |y| y.yield([1]) }.to_a.should == [[1]]
-        Enumerator.new { |y| y.yield([1]) }.first.should == [1]
-
+      it 'accepts multiple arguments' do
         Enumerator.new { |y| y.yield(1, 2) }.to_a.should == [[1, 2]]
         Enumerator.new { |y| y.yield(1, 2) }.first.should == [1, 2]
+      end
+
+      it "doesn't double-wrap arrays" do
+        Enumerator.new { |y| y.yield([1]) }.to_a.should == [[1]]
+        Enumerator.new { |y| y.yield([1]) }.first.should == [1]
 
         Enumerator.new { |y| y.yield([1, 2]) }.to_a.should == [[1, 2]]
         Enumerator.new { |y| y.yield([1, 2]) }.first.should == [1, 2]
       end
 
-      it 'handles << arguments properly' do
+      it 'returns nil' do
+        ScratchPad.record []
+        Enumerator.new do |y|
+          ScratchPad << y.yield(1)
+        end.to_a
+
+        ScratchPad.recorded.should == [nil]
+      end
+
+      it 'accepts keyword arguments and treats them as a positional hash' do
+        Enumerator.new { |y| y.yield(foo: 42) }.to_a.should == [{ foo: 42 }]
+        Enumerator.new { |y| y.yield(foo: 42) }.first.should == { foo: 42 }
+
+        Enumerator.new { |y| y.yield(123, foo: 42) }.to_a.should == [[123, { foo: 42 }]]
+        Enumerator.new { |y| y.yield(123, foo: 42) }.first.should == [123, { foo: 42 }]
+      end
+    end
+
+    describe '#<<' do
+      it 'accepts a single argument' do
         Enumerator.new { |y| y.<<(1) }.to_a.should == [1]
         Enumerator.new { |y| y.<<(1) }.first.should == 1
+      end
 
+      it "doesn't double-wrap arrays" do
         Enumerator.new { |y| y.<<([1]) }.to_a.should == [[1]]
         Enumerator.new { |y| y.<<([1]) }.first.should == [1]
 
-        # << doesn't accept multiple arguments
-        # Enumerator.new { |y| y.<<(1, 2) }.to_a.should == [[1, 2]]
-        # Enumerator.new { |y| y.<<(1, 2) }.first.should == [1, 2]
-
         Enumerator.new { |y| y.<<([1, 2]) }.to_a.should == [[1, 2]]
         Enumerator.new { |y| y.<<([1, 2]) }.first.should == [1, 2]
       end
+
+      it 'accepts keyword arguments and treats them as a positional hash' do
+        Enumerator.new { |y| y.<<(foo: 42) }.to_a.should == [{ foo: 42 }]
+        Enumerator.new { |y| y.<<(foo: 42) }.first.should == { foo: 42 }
+      end
+
+      it 'can be chained' do
+        enum = Enumerator.new do |y|
+          y << 1 << 2
+        end
+        enum.to_a.should == [1, 2]
+      end
+
+      it 'raises ArgumentError when given more than one argument' do
+        -> {
+          Enumerator.new { |y| y.<<(1, 2) }.to_a
+        }.should.raise(ArgumentError, "wrong number of arguments (given 2, expected 1)")
+      end
     end
   end
 end