show-source/show-doc: Show the first module candidate with source/docs

Prior to this change `show-source ActiveRecord::Base` would fail, as the highest ranked
candidate couldn't be discovered.

lib/pry/commands/show_info.rb

@@ -19,24 +19,40 @@ class Pry
 
     def process
       code_object = Pry::CodeObject.lookup(obj_name, _pry_, :super => opts[:super])
-      raise Pry::CommandError, "Couldn't locate #{obj_name}!" if !code_object
+      cannot_locate_source_error if !code_object
 
       if show_all_modules?(code_object)
         # show all monkey patches for a module
 
-        @all_modules = true
         result = content_and_headers_for_all_module_candidates(code_object)
       else
         # show a specific code object
 
-        @all_modules = false
-        result = content_and_header_for_code_object(code_object)
+        co = code_object_with_accessible_source(code_object)
+        result = content_and_header_for_code_object(co)
       end
 
       set_file_and_dir_locals(code_object.source_file)
       stagger_output result
     end
 
+    # This method checks whether the `code_object` is a WrappedModule,
+    # if it is, then it returns the first candidate (monkeypatch) with
+    # accessible source (or docs). If `code_object` is not a WrappedModule (i.e a
+    # method or a command) then the `code_object` itself is just
+    # returned.
+    #
+    # @return [Pry::WrappedModule, Pry::Method, Pry::Command]
+    def code_object_with_accessible_source(code_object)
+      if code_object.is_a?(WrappedModule)
+        code_object.candidates.find(&:source).tap do |candidate|
+          cannot_locate_source_error if !candidate
+        end
+      else
+        code_object
+      end
+    end
+
     def content_and_header_for_code_object(code_object)
       header(code_object) + content_for(code_object)
     end
@@ -58,6 +74,10 @@ class Pry
       result
     end
 
+    def cannot_locate_source_error
+      raise CommandError, "Couldn't locate a definition for #{obj_name}!"
+    end
+
     # Generate a header (meta-data information) for all the code
     # object types: methods, modules, commands, procs...
     def header(code_object)
@@ -124,10 +144,6 @@ class Pry
       end
     end
 
-    def all_modules?
-      @all_modules
-    end
-
     def complete(input)
       if input =~ /([^ ]*)#([a-z0-9_]*)\z/
         prefix, search = [$1, $2]

lib/pry/commands/show_source.rb

@@ -25,6 +25,8 @@ class Pry
 
     # The source for code_object prepared for display.
     def content_for(code_object)
+      cannot_locate_source_error if !code_object.source
+
       Code.new(code_object.source, start_line_for(code_object)).
         with_line_numbers(use_line_numbers?).to_s
     end

spec/commands/show_doc_spec.rb

@@ -279,34 +279,34 @@ if !PryTestHelpers.mri18_and_no_real_source_location?
 
       # FIXME: THis is nto a good spec anyway, because i dont think it
       # SHOULD skip!
-      # describe "should skip over broken modules" do
-      #   before do
-      #     module TestHost
-      #       # hello
-      #       module M
-      #         binding.eval("def a; end", "dummy.rb", 1)
-      #         binding.eval("def b; end", "dummy.rb", 2)
-      #         binding.eval("def c; end", "dummy.rb", 3)
-      #       end
+      describe "should skip over broken modules" do
+        before do
+          module TestHost
+            # hello
+            module M
+              binding.eval("def a; end", "dummy.rb", 1)
+              binding.eval("def b; end", "dummy.rb", 2)
+              binding.eval("def c; end", "dummy.rb", 3)
+            end
 
-      #       # goodbye
-      #       module M
-      #         def d; end
-      #         def e; end
-      #       end
-      #     end
-      #   end
+            # goodbye
+            module M
+              def d; end
+              def e; end
+            end
+          end
+        end
 
-      #   after do
-      #     Object.remove_const(:TestHost)
-      #   end
+        after do
+          Object.remove_const(:TestHost)
+        end
 
-      #   it 'should return doc for first valid module' do
-      #     result = pry_eval("show-doc TestHost::M")
-      #     result.should =~ /goodbye/
-      #     result.should.not =~ /hello/
-      #   end
-      # end
+        it 'should return doc for first valid module' do
+          result = pry_eval("show-doc TestHost::M")
+          result.should =~ /goodbye/
+          result.should.not =~ /hello/
+        end
+      end
     end
 
     describe "on commands" do

spec/commands/show_source_spec.rb

@@ -491,7 +491,7 @@ if !PryTestHelpers.mri18_and_no_real_source_location?
             proc {
               pry_eval(TestHost::C, 'show-source')
             }.should.raise(Pry::CommandError).
-              message.should =~ /Cannot find a definition for/
+              message.should =~ /Couldn't locate/
           end
 
           it 'should display method code (rather than class) if Pry started inside method binding' do
@@ -535,14 +535,11 @@ if !PryTestHelpers.mri18_and_no_real_source_location?
               Object.remove_const(:BabyDuck)
             end
 
-            # TODO: !!! This is a bad spec, should not be expected behaviour?!?!
-            #
-            # it 'should return source for first valid module' do
-            #   out = pry_eval('show-source BabyDuck::Muesli')
-            #   out.should =~ /def d; end/
-            #   out.should.not =~ /def a; end/
-            # end
-
+            it 'should return source for first valid module' do
+              out = pry_eval('show-source BabyDuck::Muesli')
+              out.should =~ /def d; end/
+              out.should.not =~ /def a; end/
+            end
           end
         end
       end