1 files changed, 54 insertions, 0 deletions
diff --git a/tooling/graphql/docs/renderer.rb b/tooling/graphql/docs/renderer.rb
new file mode 100644
index 00000000000..0c2e8cb3b86
--- /dev/null
+++ b/tooling/graphql/docs/renderer.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+require_relative 'helper'
+
+module Tooling
+  module Graphql
+    module Docs
+      # Gitlab renderer for graphql-docs.
+      # Uses HAML templates to parse markdown and generate .md files.
+      # It uses graphql-docs helpers and schema parser, more information in https://github.com/gjtorikian/graphql-docs.
+      #
+      # Arguments:
+      #   schema - the GraphQL schema definition. For GitLab should be: GitlabSchema
+      #   output_dir: The folder where the markdown files will be saved
+      #   template: The path of the haml template to be parsed
+      class Renderer
+        include Tooling::Graphql::Docs::Helper
+
+        attr_reader :schema
+
+        def initialize(schema, output_dir:, template:)
+          @output_dir = output_dir
+          @template = template
+          @layout = Haml::Engine.new(File.read(template))
+          @parsed_schema = GraphQLDocs::Parser.new(schema.graphql_definition, {}).parse
+          @schema = schema
+          @seen = Set.new
+        end
+
+        def contents
+          # Render and remove an extra trailing new line
+          @contents ||= @layout.render(self).sub!(/\n(?=\Z)/, '')
+        end
+
+        def write
+          filename = File.join(@output_dir, 'index.md')
+
+          FileUtils.mkdir_p(@output_dir)
+          File.write(filename, contents)
+        end
+
+        private
+
+        def seen_type?(name)
+          @seen.include?(name)
+        end
+
+        def seen_type!(name)
+          @seen << name
+        end
+      end
+    end
+  end
+end