sub-items.rb

# User signs up for 'free' and adds 'ip_addresses' (3 units)
# Datapoint1
# subcription.items:
[
  {
    product_id: free.id,
    component_id: ip_addresses.id,
    name: "IP Addresses",
    mrr: 30_00,
    mrr_movements: [{ amount: 30_00, category: "new_business" }],
    quantity: 3,
  },
]

# User upgrades to 'Advanced'
# Datapoint2
# subcription.items:
[
  {
    product_id: advanced.id,
    component_id: 0,
    name: "Advanced",
    mrr: 100_00,
    mrr_movements: [{ amount: 100_00, category: "expansion" }],
    quantity: 1,
  },
  {
    product_id: free.id,
    component_id: ip_addresses.id,
    name: "IP Addresses",
    mrr: 0,
    mrr_movements: [{ amount: -30_00, category: "switch" }],
    quantity: 0,
  },
  {
    product_id: advanced.id,
    component_id: ip_addresses.id,
    name: "IP Addresses",
    mrr: 30_00,
    mrr_movements: [{ amount: 30_00, category: "switch" }],
    quantity: 3,
  }
]

# Nowhere on Datapoint2 does the name of product `free` exist, because we don't
# persist sub-items for $0, so the best that we can do to describe the
# $30 `ip_addresses` switch movement is:
#
# "$30.00/mo moved to Advanced as IP Addresses"