graphql-errors

This gem provides a simple error handling for graphql-ruby.

Highlights

• Error handling for each field.
• Logic inside the rescue_from block, similarly to Rails.
• Catching exceptions by ancestors, e.g. CustomError with rescue_from StandardError.
• Per schema configuration.
• No dependencies.

Usage

Once you defined your GraphQL schema:

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

You can add rescue_from error handlers with GraphQL::Errors. For example:

GraphQL::Errors.configure(Schema) do
  rescue_from ActiveRecord::RecordNotFound do |exception|
    nil
  end

  rescue_from ActiveRecord::RecordInvalid do |exception|
    GraphQL::ExecutionError.new(exception.record.errors.full_messages.join("\n"))
  end

  # uses Module to handle several similar errors with single rescue_from
  rescue_from MyNetworkErrors do |_|
    GraphQL::ExecutionError.new("Don't mind, just retry the mutation")
  end

  rescue_from StandardError do |exception|
    GraphQL::ExecutionError.new("Please try to execute the query for this field later")
  end

  rescue_from CustomError do |exception, object, arguments, context|
    error = GraphQL::ExecutionError.new("Error found!")
    firstError.path = context.path + ["myError"]
    context.add_error(firstError)
  end
end

It'll handle exceptions raised from each resolver in the schema:

QueryType = GraphQL::ObjectType.define do
  name "Query"

  field :post, PostType do
    argument :id, !types.ID
    resolve ->(obj, args, ctx) { Post.find(args['id']) } # <= will raise ActiveRecord::RecordNotFound
  end
end

Schema.execute('query { post(id: "1") { title } }') # handles the error without failing the whole query
# => { data: { post: nil } }

Installation

Add this line to your application's Gemfile:

gem 'graphql-errors'

And then execute:

$ bundle

Or install it yourself as:

$ gem install graphql-errors

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-errors. 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::Errors project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.