feat(cascade-plan-changes): add api and GQL support for cascade featu…

…re (#2726)

## Context

Currently when plan is updated, these changes are not cascaded to all
the children plans.

## Description

This PR adds `cascade_updates` attribute that allows user to skip
cascade action.

Also, this PR includes `has_overridden_plans` attribute on GQL plan
object.

app/controllers/api/v1/plans_controller.rb

@@ -77,6 +77,7 @@ def input_params
           :trial_period,
           :pay_in_advance,
           :bill_charges_monthly,
+          :cascade_updates,
           tax_codes: [],
           minimum_commitment: [
             :id,

app/graphql/mutations/plans/update.rb

@@ -13,6 +13,7 @@ class Update < BaseMutation
       argument :amount_cents, GraphQL::Types::BigInt, required: true
       argument :amount_currency, Types::CurrencyEnum, required: true
       argument :bill_charges_monthly, Boolean, required: false
+      argument :cascade_updates, Boolean, required: false
       argument :code, String, required: true
       argument :description, String, required: false
       argument :id, String, required: true

app/graphql/types/plans/object.rb

@@ -25,6 +25,8 @@ class Object < Types::BaseObject
       field :charges, [Types::Charges::Object]
       field :taxes, [Types::Taxes::Object]
 
+      field :has_overridden_plans, Boolean
+
       field :created_at, GraphQL::Types::ISO8601DateTime, null: false
       field :updated_at, GraphQL::Types::ISO8601DateTime, null: false
 
@@ -46,6 +48,10 @@ def charges_count
         object.charges.count
       end
 
+      def has_overridden_plans
+        object.children.any?
+      end
+
       def subscriptions_count
         count = object.subscriptions.count
         return count unless object.children

spec/graphql/types/plans/object_spec.rb

@@ -12,6 +12,7 @@
   it { is_expected.to have_field(:bill_charges_monthly).of_type('Boolean') }
   it { is_expected.to have_field(:code).of_type('String!') }
   it { is_expected.to have_field(:description).of_type('String') }
+  it { is_expected.to have_field(:has_overridden_plans).of_type('Boolean') }
   it { is_expected.to have_field(:interval).of_type('PlanInterval!') }
   it { is_expected.to have_field(:invoice_display_name).of_type('String') }
   it { is_expected.to have_field(:minimum_commitment).of_type('Commitment') }