Improve Graphql Docs

Adds more friendly docs for GraphQl implementation

Gemfile

@@ -84,6 +84,7 @@ gem 'rack-cors', '~> 1.0.0', require: 'rack/cors'
 gem 'graphql', '~> 1.8.0'
 gem 'graphiql-rails', '~> 1.4.10'
 gem 'apollo_upload_server', '~> 2.0.0.beta3'
+gem 'graphql-docs', '~> 1.6.0', group: [:development, :test]
 
 # Disable strong_params so that Mash does not respond to :permitted?
 gem 'hashie-forbidden_attributes'

Gemfile.lock

@@ -216,6 +216,8 @@ GEM
     excon (0.62.0)
     execjs (2.6.0)
     expression_parser (0.9.0)
+    extended-markdown-filter (0.6.0)
+      html-pipeline (~> 2.0)
     factory_bot (4.8.2)
       activesupport (>= 3.0.0)
     factory_bot_rails (4.8.2)
@@ -290,6 +292,7 @@ GEM
     fuubar (2.2.0)
       rspec-core (~> 3.0)
       ruby-progressbar (~> 1.4)
+    gemoji (3.0.1)
     gemojione (3.3.0)
       json
     get_process_mem (0.2.3)
@@ -370,6 +373,14 @@ GEM
       railties
       sprockets-rails
     graphql (1.8.1)
+    graphql-docs (1.6.0)
+      commonmarker (~> 0.16)
+      escape_utils (~> 1.2)
+      extended-markdown-filter (~> 0.4)
+      gemoji (~> 3.0)
+      graphql (~> 1.6)
+      html-pipeline (~> 2.8)
+      sass (~> 3.4)
     grpc (1.19.0)
       google-protobuf (~> 3.1)
       googleapis-common-protos-types (~> 1.0.0)
@@ -1118,6 +1129,7 @@ DEPENDENCIES
   grape_logging (~> 1.7)
   graphiql-rails (~> 1.4.10)
   graphql (~> 1.8.0)
+  graphql-docs (~> 1.6.0)
   grpc (~> 1.19.0)
   haml_lint (~> 0.31.0)
   hamlit (~> 2.8.8)

doc/api/graphql/index.md

@@ -47,6 +47,12 @@ info about multiplexed queries is also available for
 [graphql-ruby](https://graphql-ruby.org/queries/multiplex.html) the
 library GitLab uses on the backend.
 
+## Reference
+
+GitLab's GraphQL reference [is available](reference/index.md).
+
+It is automatically generated from GitLab's GraphQL schema and embedded in a Markdown file.
+
 ## GraphiQL
 
 The API can be explored by using the GraphiQL IDE, it is available on your

lib/gitlab/graphql/docs/helper.rb

+# frozen_string_literal: true
+
+return if Rails.env.production?
+
+module Gitlab
+  module Graphql
+    module Docs
+      # Helper with functions to be used by HAML templates
+      # This includes graphql-docs gem helpers class.
+      # You can check the included module on: https://github.com/gjtorikian/graphql-docs/blob/v1.6.0/lib/graphql-docs/helpers.rb
+      module Helper
+        include GraphQLDocs::Helpers
+
+        def auto_generated_comment
+          <<-MD.strip_heredoc
+            <!---
+              This documentation is auto generated by a script.
+
+              Please do not edit this file directly, check compile_docs task on lib/tasks/gitlab/graphql.rake.
+            --->
+          MD
+        end
+
+        # Some fields types are arrays of other types and are displayed
+        # on docs wrapped in square brackets, for example: [String!].
+        # This makes GitLab docs renderer thinks they are links so here
+        # we change them to be rendered as: String! => Array.
+        def render_field_type(type)
+          array_type = type[/\[(.+)\]/, 1]
+
+          if array_type
+            "#{array_type} => Array"
+          else
+            type
+          end
+        end
+
+        # We are ignoring connections and built in types for now,
+        # they should be added when queries are generated.
+        def objects
+          graphql_object_types.select do |object_type|
+            !object_type[:name]["Connection"] &&
+              !object_type[:name]["Edge"] &&
+              !object_type[:name]["__"]
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/graphql/docs/renderer.rb

+# frozen_string_literal: true
+
+return if Rails.env.production?
+
+module Gitlab
+  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 defition. For GitLab should be: GitlabSchema.graphql_definition
+      #   output_dir: The folder where the markdown files will be saved
+      #   template: The path of the haml template to be parsed
+      class Renderer
+        include Gitlab::Graphql::Docs::Helper
+
+        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, {}).parse
+        end
+
+        def render
+          contents = @layout.render(self)
+
+          write_file(contents)
+        end
+
+        private
+
+        def write_file(contents)
+          filename = File.join(@output_dir, 'index.md')
+
+          FileUtils.mkdir_p(@output_dir)
+          File.write(filename, contents)
+        end
+      end
+    end
+  end
+end

lib/gitlab/graphql/docs/templates/default.md.haml

+-# haml-lint:disable UnnecessaryStringOutput
+
+= auto_generated_comment
+
+:plain
+  # GraphQL API Resources
+
+  This documentation is self-generated based on GitLab current GraphQL schema.
+
+  The API can be explored interactively using the [GraphiQL IDE](../index.md#graphiql).
+
+  ## Objects
+\
+- objects.each do |type|
+  - unless type[:fields].empty?
+    = "### #{type[:name]}"
+    \
+    ~ "| Name  | Type  | Description |"
+    ~ "| ---   |  ---- | ----------  |"
+    - type[:fields].each do |field|
+      = "| `#{field[:name]}` | #{render_field_type(field[:type][:info])} | #{field[:description]} |"
+    \
+
+
+

lib/tasks/gitlab/graphql.rake

+# frozen_string_literal: true
+
+return if Rails.env.production?
+
+namespace :gitlab do
+  OUTPUT_DIR = Rails.root.join("doc/api/graphql/reference").freeze
+  TEMPLATES_DIR = 'lib/gitlab/graphql/docs/templates/'.freeze
+
+  namespace :graphql do
+    desc 'GitLab | Generate GraphQL docs'
+    task compile_docs: :environment do
+      renderer = Gitlab::Graphql::Docs::Renderer.new(GitlabSchema.graphql_definition, render_options)
+
+      renderer.render
+
+      puts "Documentation compiled."
+    end
+  end
+end
+
+def render_options
+  {
+    output_dir: OUTPUT_DIR,
+    template: Rails.root.join(TEMPLATES_DIR, 'default.md.haml')
+  }
+end