Rspec::GraphqlMatchers

Convenient rspec matchers for testing your graphql-ruby API/Schema.

Installation

gem 'rspec-graphql_matchers'

Usage

The matchers currently supported are:

• expect(a_graphql_object).to have_a_field(field_name).of_type(valid_type)
• expect(a_graphql_object).to implement(interface_name, ...)
• expect(a_mutation_type).to have_a_return_field(field_name).returning(valid_type)
• expect(a_mutation_type).to have_an_input_field(field_name).of_type(valid_type)
• expect(a_field).to be_of_type(valid_type)
• expect(an_input).to accept_argument(argument_name).of_type(valid_type)

Where a valid type for the expectation is either:

• A reference to the actual type you expect;
• [Recommended] A String representation of a type: "String!", "Int!", "[String]!" (note the exclamation mark at the end, as required by the GraphQL specs.

For objects defined with the legacy #define api, testing :property, :hash_key and metadata is also possible by chaining .with_property, .with_hash_key and .with_metadata. For example:

• expect(a_graphql_object).to have_a_field(field_name).with_property(property_name).with_metadata(metadata_hash)
• expect(a_graphql_object).to have_a_field(field_name).with_hash_key(hash_key)

Examples

Given a GraphQL object defined as

class PostType < GraphQL::Schema::Object
  graphql_name "Post"
  description "A blog post"

  implements GraphQL::Relay::Node.interface

  field :id, ID, null: false
  field :comments, [String], null: false
  field :isPublished, Boolean, null: true

  field :subposts, PostType, null: true do
    argument :filter, types.String, required: false
    argument :id, types.ID, required: false
  end
end

1) Test your type defines the correct fields:

describe PostType do
  subject { described_class }

  it { is_expected.to have_field(:id).of_type(!types.ID) }
  it { is_expected.to have_field(:comments).of_type("[String!]!") }
  it { is_expected.to have_field(:isPublished).of_type("Boolean") }
end

2) Test a specific field type with be_of_type matcher:

describe PostType do
  describe 'id' do
    subject { PostType.fields['id'] }

    it { is_expected.to be_of_type('ID!') }
    it { is_expected.not_to be_of_type('Float!') }
  end

  describe 'subposts' do
    subject { PostType.fields['subposts'] }

    it { is_expected.to be_of_type('Post') }
  end
end

3) For objects defined using the legacy #define api, you can also use with_property, with_hash_key and with_metadata:

PostTypeWithDefineApi = GraphQL::ObjectType.define do
  name "DefinedPost"

  interfaces [GraphQL::Relay::Node.interface]

  field :id, !types.ID, property: :post_id
  field :comments, !types[types.String], hash_key: :post_comments
  field :isPublished, admin_only: true
end

describe PostTypeWithDefineApi do
  it { is_expected.to have_a_field(:id).of_type('ID!').with_property(:post_id) }
  it { is_expected.to have_a_field(:comments).with_hash_key(:post_comments) }
  it { is_expected.to have_a_field(:isPublished).with_metadata(admin_only: true) }
end

4) Test the arguments accepted by a field with accept_argument matcher:

describe PostType do
  describe 'subposts' do
    subject { PostType.fields['subposts'] }

    it 'accepts a filter and an id argument, of types String and ID' do
      expect(subject).to accept_argument(:filter).of_type('String')
      expect(subject).to accept_argument(:id).of_type('ID')
    end

    it { is_expected.not_to accept_argument(:weirdo) }
  end
end

5) Test an object's interface implementations:

describe PostType do
  subject { described_class }

  it 'implements interface Node' do
    expect(subject).to implement('Node')
  end

  # Accepts arguments as an array and type objects directly
  it { is_expected.to implement(GraphQL::Relay::Node.interface) }
  it { is_expected.not_to implement('OtherInterface') }
end

TODO

• Support GraphQL 1.9.x;
• Check the method used for resolving a field;
• New matchers!

Contributing

• Send Bug reports, suggestions or any general question through the Issue tracker. Think of another matcher that could be useful? This is the place to ask, or...
• Pull requests are welcome through the usual procedure: fork the project, commit your changes and open the PR.

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.