feat(dunning): Mutation to delete a dunning campaign

app/graphql/mutations/dunning_campaigns/destroy.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module Mutations
+  module DunningCampaigns
+    class Destroy < BaseMutation
+      include AuthenticableApiUser
+      include RequiredOrganization
+
+      REQUIRED_PERMISSION = "dunning_campaigns:delete"
+
+      graphql_name "DestroyDunningCampaign"
+      description "Deletes a dunning campaign"
+
+      argument :id, ID, required: true
+
+      field :id, ID, null: true
+
+      def resolve(id:)
+        dunning_campaign = current_organization.dunning_campaigns.find_by(id:)
+        result = ::DunningCampaigns::DestroyService.call(dunning_campaign:)
+
+        result.success? ? result.dunning_campaign : result_error(result)
+      end
+    end
+  end
+end

app/graphql/types/mutation_type.rb

@@ -149,6 +149,7 @@ class MutationType < Types::BaseObject
     field :okta_login, mutation: Mutations::Auth::Okta::Login
 
     field :create_dunning_campaign, mutation: Mutations::DunningCampaigns::Create
+    field :destroy_dunning_campaign, mutation: Mutations::DunningCampaigns::Destroy
     field :update_dunning_campaign, mutation: Mutations::DunningCampaigns::Update
 
     field :create_api_key, mutation: Mutations::ApiKeys::Create

app/services/dunning_campaigns/destroy_service.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+module DunningCampaigns
+  class DestroyService < BaseService
+    def initialize(dunning_campaign:)
+      @dunning_campaign = dunning_campaign
+
+      super
+    end
+
+    def call
+      return result.not_found_failure!(resource: "dunning_campaign") unless dunning_campaign
+      return result.forbidden_failure! unless dunning_campaign.organization.auto_dunning_enabled?
+
+      ActiveRecord::Base.transaction do
+        dunning_campaign.discard!
+        dunning_campaign.thresholds.discard_all
+
+        # TODO: Reset counters for customers that were in the dunning campaign
+      end
+
+      result.dunning_campaign = dunning_campaign
+      result
+    end
+
+    private
+
+    attr_reader :dunning_campaign
+  end
+end

spec/graphql/mutations/dunning_campaigns/destroy_spec.rb

@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+RSpec.describe Mutations::DunningCampaigns::Destroy, type: :graphql do
+  let(:required_permissions) { "dunning_campaigns:delete" }
+  let(:membership) { create(:membership, organization:) }
+  let(:organization) { create(:organization, premium_integrations: ["auto_dunning"]) }
+  let(:dunning_campaign) { create(:dunning_campaign, organization:) }
+
+  let(:mutation) do
+    <<-GQL
+      mutation($input: DestroyDunningCampaignInput!) {
+        destroyDunningCampaign(input: $input) {
+          id
+        }
+      }
+    GQL
+  end
+
+  around { |test| lago_premium!(&test) }
+
+  it_behaves_like "requires current user"
+  it_behaves_like "requires current organization"
+  it_behaves_like "requires permission", "dunning_campaigns:delete"
+
+  it "deletes a dunning campaign" do
+    result = execute_graphql(
+      current_user: membership.user,
+      current_organization: organization,
+      permissions: required_permissions,
+      query: mutation,
+      variables: {
+        input: {id: dunning_campaign.id}
+      }
+    )
+
+    data = result["data"]["destroyDunningCampaign"]
+    expect(data["id"]).to eq(dunning_campaign.id)
+  end
+
+  context "when dunnign campaign is not found" do
+    let(:dunning_campaign) { create(:dunning_campaign) }
+
+    it "returns an error" do
+      result = execute_graphql(
+        current_user: membership.user,
+        current_organization: organization,
+        permissions: required_permissions,
+        query: mutation,
+        variables: {
+          input: {id: dunning_campaign.id}
+        }
+      )
+
+      expect_graphql_error(result:, message: "Resource not found")
+    end
+  end
+end