1 files changed, 24 insertions, 0 deletions
diff --git a/spec/ruby/core/enumerator/chain/size_spec.rb b/spec/ruby/core/enumerator/chain/size_spec.rb
new file mode 100644
index 0000000000..42c31ac10b
--- /dev/null
+++ b/spec/ruby/core/enumerator/chain/size_spec.rb
@@ -0,0 +1,24 @@
+require_relative '../../../spec_helper'
+require_relative '../../enumerable/fixtures/classes'
+
+ruby_version_is "2.6" do
+  describe "Enumerator::Chain#size" do
+    it "returns the sum of the sizes of the elements" do
+      a = mock('size')
+      a.should_receive(:size).and_return(40)
+      Enumerator::Chain.new(a, [:a, :b]).size.should == 42
+    end
+
+    it "returns nil or Infinity for the first element of such a size" do
+      [nil, Float::INFINITY].each do |special|
+        a = mock('size')
+        a.should_receive(:size).and_return(40)
+        b = mock('special')
+        b.should_receive(:size).and_return(special)
+        c = mock('not called')
+        c.should_not_receive(:size)
+        Enumerator::Chain.new(a, b, c).size.should == special
+      end
+    end
+  end
+end