1 files changed, 29 insertions, 0 deletions
diff --git a/spec/ruby/core/io/buffer/null_spec.rb b/spec/ruby/core/io/buffer/null_spec.rb
new file mode 100644
index 0000000000..3fb1144d0e
--- /dev/null
+++ b/spec/ruby/core/io/buffer/null_spec.rb
@@ -0,0 +1,29 @@
+require_relative '../../../spec_helper'
+require_relative 'shared/null_and_empty'
+
+describe "IO::Buffer#null?" do
+  after :each do
+    @buffer&.free
+    @buffer = nil
+  end
+
+  it_behaves_like :io_buffer_null_and_empty, :null?
+
+  it "is false for a 0-length String-backed buffer created with .for" do
+    @buffer = IO::Buffer.for("")
+    @buffer.null?.should be_false
+  end
+
+  ruby_version_is "3.3" do
+    it "is false for a 0-length String-backed buffer created with .string" do
+      IO::Buffer.string(0) do |buffer|
+        buffer.null?.should be_false
+      end
+    end
+  end
+
+  it "is false for a 0-length slice of a buffer with size > 0" do
+    @buffer = IO::Buffer.new(4)
+    @buffer.slice(3, 0).null?.should be_false
+  end
+end