1 files changed, 34 insertions, 0 deletions
diff --git a/spec/ruby/library/set/superset_spec.rb b/spec/ruby/library/set/superset_spec.rb
new file mode 100644
index 0000000000..b7364f529e
--- /dev/null
+++ b/spec/ruby/library/set/superset_spec.rb
@@ -0,0 +1,34 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require 'set'
+
+describe "Set#superset?" do
+  before :each do
+    @set = Set[1, 2, 3, 4]
+  end
+
+  it "returns true if passed a Set that equals self or self is a proper superset of" do
+    @set.superset?(@set).should be_true
+    Set[].superset?(Set[]).should be_true
+
+    @set.superset?(Set[]).should be_true
+    Set[1, 2, 3].superset?(Set[]).should be_true
+    Set["a", :b, ?c].superset?(Set[]).should be_true
+
+    @set.superset?(Set[1, 2, 3]).should be_true
+    @set.superset?(Set[1, 3]).should be_true
+    @set.superset?(Set[1, 2]).should be_true
+    @set.superset?(Set[1]).should be_true
+
+    @set.superset?(Set[5]).should be_false
+    @set.superset?(Set[1, 5]).should be_false
+    @set.superset?(Set[nil]).should be_false
+    @set.superset?(Set["test"]).should be_false
+  end
+
+  it "raises an ArgumentError when passed a non-Set" do
+    lambda { Set[].superset?([]) }.should raise_error(ArgumentError)
+    lambda { Set[].superset?(1) }.should raise_error(ArgumentError)
+    lambda { Set[].superset?("test") }.should raise_error(ArgumentError)
+    lambda { Set[].superset?(Object.new) }.should raise_error(ArgumentError)
+  end
+end