add Pry::WrappedModule#super

It's useful having Pry::WrappedModule and Pry::Method share as much interface as possible so that
methods can be indifferent to which one they get (a la show-source / edit)

lib/pry/wrapped_module.rb

@@ -204,6 +204,24 @@ class Pry
       !!(defined?(YARD) && YARD::Registry.at(name))
     end
 
+    # @param [Fixnum] times How far to travel up the ancestor chain.
+    # @return [Pry::WrappedModule, nil] The wrapped module that is the
+    #   superclass.
+    #   When `self` is a `Module` then return the
+    #   nth ancestor, otherwise (in the case of classes) return the
+    #   nth ancestor that is a class.
+    def super(times=1)
+      return self if times.zero?
+
+      if wrapped.is_a?(Class)
+        sup = ancestors.select { |v| v.is_a?(Class) }[times]
+      else
+        sup = ancestors[times]
+      end
+
+      Pry::WrappedModule(sup) if sup
+    end
+
     private
 
     # @return [Pry::WrappedModule::Candidate] The candidate of rank 0,

spec/wrapped_module_spec.rb

@@ -168,5 +168,59 @@ describe Pry::WrappedModule do
       Pry::WrappedModule.new(class << Object; self; end).singleton_instance.should.equal?(Object)
     end
   end
-end
 
+  describe ".super" do
+    describe "receiver is a class" do
+      before do
+        @a = Class.new
+        @m = Module.new
+        @b = Class.new(@a)
+        @b.send(:include, @m)
+        @c = Class.new(@b)
+      end
+
+      it 'should return superclass for a wrapped class'  do
+        Pry::WrappedModule(@c).super.wrapped.should == @b
+      end
+
+      it 'should return nth superclass for a wrapped class'  do
+        d = Class.new(@c)
+        Pry::WrappedModule(d).super(2).wrapped.should == @b
+      end
+
+      it 'should ignore modules when retrieving nth superclass'  do
+        Pry::WrappedModule(@c).super(2).wrapped.should == @a
+      end
+
+      it 'should return nil when no nth superclass exists' do
+        Pry::WrappedModule(@c).super(10).should == nil
+      end
+
+      it 'should return self when .super(0) is used' do
+        c = Pry::WrappedModule(@c)
+        c.super(0).should == c
+      end
+    end
+
+    describe "receiver is a module" do
+      before do
+        @m1 = Module.new
+        @m2 = Module.new.tap { |v| v.send(:include, @m1) }
+        @m3 = Module.new.tap { |v| v.send(:include, @m2) }
+      end
+
+      it 'should not ignore modules when retrieving supers' do
+        Pry::WrappedModule(@m3).super.wrapped.should == @m2
+      end
+
+      it 'should retrieve nth super' do
+        Pry::WrappedModule(@m3).super(2).wrapped.should == @m1
+      end
+
+      it 'should return self when .super(0) is used' do
+        m = Pry::WrappedModule(@m1)
+        m.super(0).should == m
+      end
+    end
+  end
+end