Improve Graphql Docs

Adds more friendly docs for GraphQl implementation

3 files changed, 118 insertions, 0 deletions

diff --git a/lib/gitlab/graphql/docs/helper.rb b/lib/gitlab/graphql/docs/helper.rb
new file mode 100644
index 00000000000..ac2a78c0f28
--- /dev/null
+++ b/lib/gitlab/graphql/docs/helper.rb
@@ -0,0 +1,50 @@
+# 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
diff --git a/lib/gitlab/graphql/docs/renderer.rb b/lib/gitlab/graphql/docs/renderer.rb
new file mode 100644
index 00000000000..f47a372aa19
--- /dev/null
+++ b/lib/gitlab/graphql/docs/renderer.rb
@@ -0,0 +1,43 @@
+# 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
diff --git a/lib/gitlab/graphql/docs/templates/default.md.haml b/lib/gitlab/graphql/docs/templates/default.md.haml
new file mode 100644
index 00000000000..cc22d43ab4f
--- /dev/null
+++ b/lib/gitlab/graphql/docs/templates/default.md.haml
@@ -0,0 +1,25 @@
+-# 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]} |"
+    \
+
+
+