GraphQL Testing Reference

# spec/graphql/mutations/create_order_spec.rb
RSpec.describe "Mutations::CreateOrder" do
  let(:user)    { create(:user) }
  let(:product) { create(:product, stock: 5) }
  let(:query) do
    <<~GQL
      mutation CreateOrder($productId: ID!, $quantity: Int!) {
        createOrder(input: { productId: $productId, quantity: $quantity }) {
          order { id }
          errors
        }
      }
    GQL
  end

  subject(:result) do
    AppSchema.execute(query, variables: { productId: product.id, quantity: 1 },
                              context: { current_user: user })
  end

  it "creates an order" do
    expect(result.dig("data", "createOrder", "errors")).to be_empty
    expect(result.dig("data", "createOrder", "order", "id")).to be_present
  end

  context "when unauthenticated" do
    subject(:result) { AppSchema.execute(query, variables: { productId: product.id, quantity: 1 }) }

    it "returns an authorization error" do
      expect(result["errors"]).not_to be_empty
    end
  end
end