Revert "SortedSet was removed at a3db08d7b6ff119223f77e3df00b4f6deac971e2"

* This reverts commit b06ffce4aef002dc47c3c5968181230e7ab8d7cc.
* Do not revert specs, wrap them with `ruby_version_is` (tool for that in next commit).

1 files changed, 33 insertions, 0 deletions

diff --git a/spec/ruby/library/set/sortedset/proper_superset_spec.rb b/spec/ruby/library/set/sortedset/proper_superset_spec.rb
new file mode 100644
index 0000000000..2699290f0e
--- /dev/null
+++ b/spec/ruby/library/set/sortedset/proper_superset_spec.rb
@@ -0,0 +1,33 @@
+require_relative '../../../spec_helper'
+require 'set'
+
+describe "SortedSet#proper_superset?" do
+  before :each do
+    @set = SortedSet[1, 2, 3, 4]
+  end
+
+  it "returns true if passed a SortedSet that self is a proper superset of" do
+    @set.proper_superset?(SortedSet[]).should be_true
+    SortedSet[1, 2, 3].proper_superset?(SortedSet[]).should be_true
+    SortedSet["a", "b", "c"].proper_superset?(SortedSet[]).should be_true
+
+    @set.proper_superset?(SortedSet[1, 2, 3]).should be_true
+    @set.proper_superset?(SortedSet[1, 3]).should be_true
+    @set.proper_superset?(SortedSet[1, 2]).should be_true
+    @set.proper_superset?(SortedSet[1]).should be_true
+
+    @set.proper_superset?(SortedSet[5]).should be_false
+    @set.proper_superset?(SortedSet[1, 5]).should be_false
+    @set.proper_superset?(SortedSet["test"]).should be_false
+
+    @set.proper_superset?(@set).should be_false
+    SortedSet[].proper_superset?(SortedSet[]).should be_false
+  end
+
+  it "raises an ArgumentError when passed a non-SortedSet" do
+    -> { SortedSet[].proper_superset?([]) }.should raise_error(ArgumentError)
+    -> { SortedSet[].proper_superset?(1) }.should raise_error(ArgumentError)
+    -> { SortedSet[].proper_superset?("test") }.should raise_error(ArgumentError)
+    -> { SortedSet[].proper_superset?(Object.new) }.should raise_error(ArgumentError)
+  end
+end