[Feature #18595] Alias String#-@ as String#dedup

1 files changed, 47 insertions, 0 deletions

diff --git a/spec/ruby/core/string/shared/dedup.rb b/spec/ruby/core/string/shared/dedup.rb
new file mode 100644
index 0000000000..345e874583
--- /dev/null
+++ b/spec/ruby/core/string/shared/dedup.rb
@@ -0,0 +1,47 @@
+describe :string_dedup, shared: true do
+  it 'returns self if the String is frozen' do
+    input  = 'foo'.freeze
+    output = input.send(@method)
+
+    output.should equal(input)
+    output.should.frozen?
+  end
+
+  it 'returns a frozen copy if the String is not frozen' do
+    input  = 'foo'
+    output = input.send(@method)
+
+    output.should.frozen?
+    output.should_not equal(input)
+    output.should == 'foo'
+  end
+
+  it "returns the same object for equal unfrozen strings" do
+    origin = "this is a string"
+    dynamic = %w(this is a string).join(' ')
+
+    origin.should_not equal(dynamic)
+    origin.send(@method).should equal(dynamic.send(@method))
+  end
+
+  it "returns the same object when it's called on the same String literal" do
+    "unfrozen string".send(@method).should equal("unfrozen string".send(@method))
+    "unfrozen string".send(@method).should_not equal("another unfrozen string".send(@method))
+  end
+
+  it "deduplicates frozen strings" do
+    dynamic = %w(this string is frozen).join(' ').freeze
+
+    dynamic.should_not equal("this string is frozen".freeze)
+
+    dynamic.send(@method).should equal("this string is frozen".freeze)
+    dynamic.send(@method).should equal("this string is frozen".send(@method).freeze)
+  end
+
+  ruby_version_is "3.0" do
+    it "interns the provided string if it is frozen" do
+      dynamic = "this string is unique and frozen #{rand}".freeze
+      dynamic.send(@method).should equal(dynamic)
+    end
+  end
+end