Update CommandImplementation to handle large stdout

HISTORY.md

@@ -1,3 +1,6 @@
+## 4.0.3 - 2024-06-06
+* Update CommandImplementation to better support large files (affecting RST and POD6 rendering)
+
 ## 4.0.2 - 2023-10-10
 * Add support for .mdx files in markdown
 

lib/github-markup.rb

@@ -1,6 +1,6 @@
 module GitHub
   module Markup
-    VERSION = '4.0.2'
+    VERSION = '4.0.3'
     Version = VERSION
   end
 end

lib/github/markup/command_implementation.rb

@@ -50,16 +50,12 @@ def execute(command, target)
         end
       else
         def execute(command, target)
-          output = Open3.popen3(*command) do |stdin, stdout, stderr, wait_thr|
-            stdin.puts target
-            stdin.close
-            if wait_thr.value.success?
-              stdout.readlines
-            else
-              raise CommandError.new(stderr.readlines.join('').strip)
-            end
-          end
-          sanitize(output.join(''), target.encoding)
+          # capture3 blocks until both buffers are written to and the process terminates, but
+          # it won't allow either buffer to fill up
+          stdout, stderr, status = Open3.capture3(*command, stdin_data: target)
+
+          raise CommandError.new(stderr) unless status.success?
+          sanitize(stdout, target.encoding)
         end
       end
 

test/markup_test.rb

@@ -130,4 +130,8 @@ def test_commonmarker_options
     assert_equal "&lt;style>.red{color: red;}&lt;/style>\n", GitHub::Markup.render_s(GitHub::Markups::MARKUP_MARKDOWN, "<style>.red{color: red;}</style>", options: {commonmarker_opts: [:UNSAFE]})
     assert_equal "<style>.red{color: red;}</style>\n", GitHub::Markup.render_s(GitHub::Markups::MARKUP_MARKDOWN, "<style>.red{color: red;}</style>", options: {commonmarker_opts: [:UNSAFE], commonmarker_exts: [:autolink, :table, :strikethrough]})
   end
+
+  def test_large_document_with_command_implementation
+    assert GitHub::Markup.render_s(:rst, File.read("test/markups/README_large.rst"))
+  end
 end