1 files changed, 25 insertions, 0 deletions
diff --git a/spec/ruby/core/string/shared/grapheme_clusters.rb b/spec/ruby/core/string/shared/grapheme_clusters.rb
new file mode 100644
index 0000000000..dd8c7ed5fe
--- /dev/null
+++ b/spec/ruby/core/string/shared/grapheme_clusters.rb
@@ -0,0 +1,25 @@
+require_relative '../../../spec_helper'
+require_relative '../fixtures/classes'
+
+describe :string_grapheme_clusters, shared: true do
+  it "passes each grapheme cluster in self to the given block" do
+    a = []
+    # test string: abc[rainbow flag emoji][paw prints]
+    "ab\u{1f3f3}\u{fe0f}\u{200d}\u{1f308}\u{1F43E}".send(@method) { |c| a << c }
+    a.should == ['a', 'b', "\u{1f3f3}\u{fe0f}\u{200d}\u{1f308}", "\u{1F43E}"]
+  end
+
+  it "returns grapheme clusters for various UTF encodings" do
+    [Encoding::UTF_16LE, Encoding::UTF_16BE, Encoding::UTF_32LE, Encoding::UTF_32BE].each do |enc|
+      a = []
+      # test string: abc[rainbow flag emoji][paw prints]
+      "ab\u{1f3f3}\u{fe0f}\u{200d}\u{1f308}\u{1F43E}".encode(enc).send(@method) { |c| a << c }
+      a.should == ['a', 'b', "\u{1f3f3}\u{fe0f}\u{200d}\u{1f308}", "\u{1F43E}"].map { |s| s.encode(enc) }
+    end
+  end
+
+  it "returns self" do
+    s = StringSpecs::MyString.new "ab\u{1f3f3}\u{fe0f}\u{200d}\u{1f308}\u{1F43E}"
+    s.send(@method) {}.should.equal?(s)
+  end
+end