WIP

lib/irb/command/show_source.rb

@@ -36,10 +36,12 @@ def execute(arg)
 
         str, esses = str.split(" -")
         super_level = esses ? esses.count("s") : 0
-        source = SourceFinder.new(@irb_context).find_source(str, super_level)
+        source_finder = SourceFinder.new(@irb_context)
+        source = source_finder.find_source(str, super_level)
+        rdoc_path = source_finder.resolve_rdoc_path(str)
 
-        if source
-          show_source(source)
+        if source || rdoc_path
+          show_source(source, rdoc_path)
         elsif super_level > 0
           puts "Error: Couldn't locate a super definition for #{str}"
         else
@@ -50,20 +52,36 @@ def execute(arg)
 
       private
 
-      def show_source(source)
-        if source.binary_file?
-          content = "\n#{bold('Defined in binary file')}: #{source.file}\n\n"
-        else
-          code = source.colorized_content || 'Source not available'
-          content = <<~CONTENT
-
-            #{bold("From")}: #{source.file}:#{source.line}
-
-            #{code.chomp}
-
-          CONTENT
-        end
-        Pager.page_content(content)
+      def show_source(source, rdoc_path)
+        # Note:
+        # - We use /master because it has better UI from the latest RDoc
+        # - The main reason this is experimental is because we can't easily verify if the documentation actually exists.
+        #   While RI may be used to display the documentation directly in a pager, it doesn't have a good API to check
+        #   if the documentation exists.
+        docs_link = "#{bold("[Experimental] View on Ruby docs")}: https://docs.ruby-lang.org/en/master/#{rdoc_path}" if rdoc_path
+
+        content =
+          if source
+            if source.binary_file?
+              <<~CONTENT
+                #{docs_link}
+                #{bold('Defined in binary file')}: #{source.file}\n\n
+              CONTENT
+            else
+              code = source.colorized_content || 'Source not available'
+              <<~CONTENT
+                #{docs_link}
+
+                #{bold("From")}: #{source.file}:#{source.line}
+
+                #{code.chomp}
+
+              CONTENT
+            end
+          else
+            docs_link
+          end
+        Pager.page_content(content) if content
       end
 
       def bold(str)

lib/irb/source_finder.rb

@@ -101,7 +101,12 @@ def resolve_rdoc_path(signature, super_level = 0)
         return unless method
 
         method_type_flag = method.owner.singleton_class? ? "c" : "i"
-        receiver.name.split("::").join("/") + ".html#method-#{method_type_flag}-#{method.name}"
+
+        if receiver.is_a?(Class)
+          receiver.name.split("::").join("/") + ".html#method-#{method_type_flag}-#{method.name}"
+        else
+          "Kernel.html#method-#{method_type_flag}-#{method.name}"
+        end
       end
     rescue EvaluationError
       nil