1 files changed, 34 insertions, 0 deletions
diff --git a/spec/ruby/core/set/add_spec.rb b/spec/ruby/core/set/add_spec.rb
new file mode 100644
index 0000000000..1ce03b1eab
--- /dev/null
+++ b/spec/ruby/core/set/add_spec.rb
@@ -0,0 +1,34 @@
+require_relative '../../spec_helper'
+require_relative 'shared/add'
+
+describe "Set#add" do
+  it_behaves_like :set_add, :add
+end
+
+describe "Set#add?" do
+  before :each do
+    @set = Set.new
+  end
+
+  it "adds the passed Object to self" do
+    @set.add?("cat")
+    @set.should.include?("cat")
+  end
+
+  it "returns self when the Object has not yet been added to self" do
+    @set.add?("cat").should.equal?(@set)
+  end
+
+  it "returns nil when the Object has already been added to self" do
+    @set.add?("cat")
+    @set.add?("cat").should == nil
+  end
+
+  it "raises RuntimeError when called during iteration" do
+    set = Set[:a, :b, :c, :d, :e, :f]
+    set.each do |_m|
+      -> { set << 1 }.should.raise(RuntimeError, /iteration/)
+    end
+    set.should == Set[:a, :b, :c, :d, :e, :f]
+  end
+end