Do not call default renderers when to_iruby_mimebundle is available

Author: mrkn

lib/iruby/display.rb

@@ -40,13 +40,23 @@ def display(obj, options = {})
           raise 'Invalid mime type' unless exact_mime.include?('/')
         end
 
-        data = render_mimebundle(obj, exact_mime, fuzzy_mime)
+        data = if obj.respond_to?(:to_iruby_mimebundle)
+                 render_mimebundle(obj, exact_mime, fuzzy_mime)
+               else
+                 {}
+               end
 
         # Render by additional formatters
         render_by_registry(data, obj, exact_mime, fuzzy_mime)
 
         # Render by to_xxx methods
-        DEFAULT_MIME_TYPE_FORMAT_METHODS.each do |mime, methods|
+        default_renderers = if obj.respond_to?(:to_iruby_mimebundle)
+                              # Do not use Hash#slice for Ruby < 2.5
+                              {"text/plain" => DEFAULT_MIME_TYPE_FORMAT_METHODS["text/plain"]}
+                            else
+                              DEFAULT_MIME_TYPE_FORMAT_METHODS
+                            end
+        default_renderers.each do |mime, methods|
           next if mime.nil? && !data.empty? # for to_iruby
 
           next if mime && data.key?(mime)   # do not overwrite
@@ -109,13 +119,11 @@ def ascii?(mime)
 
       private def render_mimebundle(obj, exact_mime, fuzzy_mime)
         data = {}
-        if obj.respond_to?(:to_iruby_mimebundle)
-          include_mime = [exact_mime].compact
-          formats, metadata = obj.to_iruby_mimebundle(include: include_mime)
-          formats.each do |mime, value|
-            if fuzzy_mime.nil? || mime.include?(fuzzy_mime)
-              data[mime] = value
-            end
+        include_mime = [exact_mime].compact
+        formats, metadata = obj.to_iruby_mimebundle(include: include_mime)
+        formats.each do |mime, value|
+          if fuzzy_mime.nil? || mime.include?(fuzzy_mime)
+            data[mime] = value
           end
         end
         data

test/iruby/display_test.rb

@@ -59,14 +59,12 @@ class << @object
         def to_iruby_mimebundle(include: [])
           @to_iruby_mimebundle_called = true
           mimes = if include.empty?
-                    ["text/html", "text/markdown", "application/json"]
+                    ["text/markdown", "application/json"]
                   else
                     include
                   end
           formats = mimes.map { |mime|
             result = case mime
-                     when "text/html"
-                       "<i>html</i>"
                      when "text/markdown"
                        "**markdown**"
                      when "application/json"
@@ -170,7 +168,6 @@ def setup
           def test_display
             assert_iruby_display({
                                    result: {
-                                     "text/html" => "<i>html</i>",
                                      "text/markdown" => "**markdown**",
                                      "application/json" => %Q[{"mimebundle": "json"}],
                                      "text/plain" => "!!! inspect !!!"