graphql-guard

This tiny gem provides a field-level authorization for graphql-ruby.

Usage

Define a GraphQL schema:

```ruby # define type PostType = GraphQL::ObjectType.define do name “Post” field :id, !types.ID field :title, !types.String end

define query

QueryType = GraphQL::ObjectType.define do name “Query” field :posts, !types[PostType] do argument :user_id, !types.ID resolve ->(_obj, args, _ctx) { Post.where(user_id: args[:user_id]) } end end

define schema

Schema = GraphQL::Schema.define do query QueryType end

execute query

GraphSchema.execute( query, variables: { user_id: 1 }, context: { current_user: current_user } ) ```

Inline policies

Add GraphQL::Guard to your schema:

ruby Schema = GraphQL::Schema.define do query QueryType use GraphQL::Guard.new # <======= ʘ‿ʘ end

Now you can define guard for a field, which will check permissions before resolving the field:

ruby QueryType = GraphQL::ObjectType.define do name "Query" field :posts, !types[PostType] do argument :user_id, !types.ID guard ->(_obj, args, ctx) { args[:user_id] == ctx[:current_user].id } # <======= ʘ‿ʘ ... end end

You can also define guard, which will be executed for all fields in the type:

ruby PostType = GraphQL::ObjectType.define do name "Post" guard ->(_post, ctx) { ctx[:current_user].admin? } # <======= ʘ‿ʘ ... end

If guard block returns false, then it’ll raise a GraphQL::Guard::NotAuthorizedError error.

Policy object

Alternatively, it’s possible to describe all policies by using PORO (Plain Old Ruby Object), which should implement a guard method. For example:

```ruby class GraphqlPolicy RULES = { QueryType => { posts: ->(_obj, args, ctx) { args[:user_id] == ctx[:current_user].id } }, PostType => { ‘*’: ->(post, ctx) { ctx[:current_user].admin? } } }

def self.guard(type, field) RULES.dig(type, field) end end ```

Use pass this object to GraphQL::Guard:

ruby Schema = GraphQL::Schema.define do query QueryType use GraphQL::Guard.new(policy_object: GraphqlPolicy) # <======= ʘ‿ʘ end

Order of priority

GraphQL::Guard will use the policy in the following order of priority:

1. Inline policy on the field.
2. Policy from the policy object on the field.
3. Inline policy on the type.
4. Policy from the policy object on the type.

```ruby class GraphqlPolicy RULES = { PostType => { title: ->(_post, ctx) { ctx[:current_user].admin? }, # <======= 2 ‘*’: ->(_post, ctx) { ctx[:current_user].admin? } # <======= 4 } }

def self.guard(type, field) RULES.dig(type, field) end end

PostType = GraphQL::ObjectType.define do name “Post” guard ->(_post, ctx) { ctx[:current_user].admin? } # <======= 3 field :title, !types.String, guard: ->(_post, _args, ctx) { ctx[:current_user].admin? } # <======= 1 end

Schema = GraphQL::Schema.define do query QueryType use GraphQL::Guard.new(policy_object: GraphqlPolicy) end ```

Installation

Add this line to your application’s Gemfile:

ruby gem 'graphql-guard'

And then execute:

$ bundle

Or install it yourself as:

$ gem install graphql-guard

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/exAspArk/graphql-guard. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Graphql::Guard project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.