pattern_matching_joe.rb

example.rb

require 'active_support/core_ext/hash/indifferent_access'

def send_admin_notification(changes = previous_changes)
  case changes
  in ends_at: [Time, _]
    :resubscribed
  in ends_at: [nil, Time]
    :churned
  in processor_plan: [nil, String]
    :subscribed
  in processor_plan: Array
    :plan_changed
  in data: [_, {pause_behaviour: nil}]
    :unpaused
  in data: [{pause_behaviour: nil},_]
    :paused
  end
end

resubscribed = {
  "ends_at": [
    Time.now - 60,
    Time.now
  ],
  "processor_plan": [
    "new",
    nil
  ],
  "data": [
    {
      "pause_behaviour": nil
    }.with_indifferent_access,
    {
      "pause_behaviour": "1"
    }.with_indifferent_access
  ]
}.with_indifferent_access


churned = {
  "ends_at": [
    nil,
    Time.now
  ],
  "processor_plan": [
    "new",
    nil
  ],
  "data": [
    {
      "pause_behaviour": nil
    }.with_indifferent_access,
    {
      "pause_behaviour": "1"
    }.with_indifferent_access
  ]
}.with_indifferent_access


subscribed = {
  "processor_plan": [
    nil,
    "new"
  ],
  "data": [
    {
      "pause_behaviour": nil
    }.with_indifferent_access,
    {
      "pause_behaviour": "1"
    }.with_indifferent_access
  ]
}.with_indifferent_access

plan_changed = {
  "processor_plan": [
    "new",
    nil
  ],
  "data": [
    {
      "pause_behaviour": nil
    }.with_indifferent_access,
    {
      "pause_behaviour": "1"
    }.with_indifferent_access
  ]
}.with_indifferent_access


unpaused = {
  "plan": [
    "new",
    nil
  ],
  "data": [
    {
      "pause_behaviour": "1",
      "other_key": "was"
    }.with_indifferent_access,
    {
      "pause_behaviour": nil,
      "other_key": "was",
      "new_key": "1"
    }.with_indifferent_access
  ]
}.with_indifferent_access

paused = {
  "plan": [
    "new",
    nil
  ],
  "data": [
    {
      "pause_behaviour": nil
    }.with_indifferent_access,
    {
      "pause_behaviour": "1"
    }.with_indifferent_access
  ]
}.with_indifferent_access


puts send_admin_notification(resubscribed)
puts send_admin_notification(churned)
puts send_admin_notification(subscribed)
puts send_admin_notification(plan_changed)
puts send_admin_notification(unpaused)
puts send_admin_notification(paused)