Show{Source,Doc}: assume super definitions from the context

Fix issue #877 (show-source -s doesn't work (when no method arg is
given))

This behaviour is shared between `show-source` and `show-doc`. So with
one fix I kill two bugs.

Add tests and rewrite some of the existing ones (related to the
`--super` switch).

lib/pry/commands/show_info.rb

@@ -155,7 +155,16 @@ class Pry
     end
 
     def obj_name
-      @obj_name ||= args.empty? ? nil : args.join(" ")
+      @obj_name ||=
+        if args.empty? && (opts[:super] && opts[:super] > 0)
+          current_method_name
+        else
+          args.join(' ')
+        end
+    end
+
+    def current_method_name
+      _pry_.current_context.eval('::Kernel.__method__').to_s
     end
 
     def use_line_numbers?

spec/commands/show_doc_spec.rb

@@ -39,33 +39,61 @@ if !PryTestHelpers.mri18_and_no_real_source_location?
       @o.sample
     end
 
-    it "should be able to find super methods" do
-      b = Class.new{
-        # daddy initialize!
-        def initialize(*args) ;end
-      }
+    describe "finding find super method docs with help of `--super` switch" do
+      before do
+        class Daddy
+          # daddy initialize!
+          def initialize(*args); end
+        end
 
-      c = Class.new(b){
-        # classy initialize!
-        def initialize(*args); end
-      }
+        class Classy < Daddy
+          # classy initialize!
+          def initialize(*args); end
+        end
 
-      d = Class.new(c){
-        # grungy initialize??
-        def initialize(*args, &block); end
-      }
+        class Grungy < Classy
+          # grungy initialize??
+          def initialize(*args); end
+        end
 
-      o = d.new
+        @o = Grungy.new
 
-      # instancey initialize!
-      def o.initialize; end
+        # instancey initialize!
+        def @o.initialize; end
+      end
 
-      t = pry_tester(binding)
+      after do
+        Object.remove_const(:Grungy)
+        Object.remove_const(:Classy)
+        Object.remove_const(:Daddy)
+      end
 
-      t.eval("show-doc o.initialize").should =~ /instancey initialize/
-      t.eval("show-doc --super o.initialize").should =~ /grungy initialize/
-      t.eval("show-doc o.initialize -ss").should =~ /classy initialize/
-      t.eval("show-doc o.initialize -sss").should =~ /daddy initialize/
+      it "finds super method docs" do
+        output = pry_eval(binding, 'show-doc --super @o.initialize')
+        output.should =~ /grungy initialize/
+      end
+
+      it "traverses ancestor chain and finds super method docs" do
+        output = pry_eval(binding, 'show-doc -ss @o.initialize')
+        output.should =~ /classy initialize/
+      end
+
+      it "traverses ancestor chain even higher and finds super method doc" do
+        output = pry_eval(binding, 'show-doc @o.initialize -sss')
+        output.should =~ /daddy initialize/
+      end
+
+      it "finds super method docs without explicit method argument" do
+        fatty = Grungy.new
+
+        # fatty initialize!
+        def fatty.initialize
+          pry_eval(binding, 'show-doc --super')
+        end
+
+        output = fatty.initialize
+        output.should =~ /grungy initialize/
+      end
     end
 
     describe "rdoc highlighting" do

spec/commands/show_source_spec.rb

@@ -123,22 +123,6 @@ if !PryTestHelpers.mri18_and_no_real_source_location?
       pry_eval(binding, "cd c", "show-source moo").should =~ /ve over/
     end
 
-    it "should find super methods" do
-      class Foo
-        def foo(*bars)
-          :super_wibble
-        end
-      end
-      o = Foo.new
-      Object.remove_const(:Foo)
-      def o.foo(*bars)
-        :wibble
-      end
-
-      pry_eval(binding, "show-source --super o.foo").
-        should =~ /:super_wibble/
-    end
-
     it "should raise a CommandError when super method doesn't exist" do
       def @o.foo(*bars); end
 
@@ -182,6 +166,40 @@ if !PryTestHelpers.mri18_and_no_real_source_location?
       end
     end
 
+    describe "finding super methods with help of `--super` switch" do
+      before do
+        class Foo
+          def foo(*bars)
+            :super_wibble
+          end
+        end
+      end
+
+      after do
+        Object.remove_const(:Foo)
+      end
+
+      it "finds super methods with explicit method argument" do
+
+        o = Foo.new
+        def o.foo(*bars)
+          :wibble
+        end
+
+        pry_eval(binding, "show-source --super o.foo").should =~ /:super_wibble/
+      end
+
+      it "finds super methods without explicit method argument" do
+        o = Foo.new
+        def o.foo(*bars)
+          :wibble
+          pry_eval(binding, 'show-source --super')
+        end
+
+        o.foo.should =~ /:super_wibble/
+      end
+    end
+
     describe "on sourcable objects" do
       if RUBY_VERSION =~ /1.9/
         it "should output source defined inside pry" do
@@ -370,6 +388,7 @@ if !PryTestHelpers.mri18_and_no_real_source_location?
             it 'should find class defined in repl' do
               pry_eval('show-source TobinaMyDog').should =~ /class TobinaMyDog/
             end
+
             it 'should find superclass defined in repl' do
               pry_eval('show-source -s TobinaMyDog').should =~ /class Dog/
             end