Add migration method

CHANGELOG.md

@@ -7,7 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 ### Changed
 - Added the `step_gid` column to the `heya_campaign_memberships` table. This
-  change requires running a migration to upgrade.
+  change requires running a migration to upgrade. [Instructions](./UPGRADING.md#0-0-4). (#83)
 
 ## [0.3.0] - 2020-06-02
 ### Added

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    heya (0.2.1)
+    heya (0.3.0)
       rails (>= 5.2.3, < 6.1.0)
 
 GEM
@@ -91,7 +91,7 @@ GEM
     minitest (5.14.2)
     minitest-ci (3.4.0)
       minitest (>= 5.0.6)
-    nio4r (2.5.3)
+    nio4r (2.5.4)
     nokogiri (1.10.10)
       mini_portile2 (~> 2.4.0)
     parallel (1.19.2)
@@ -158,7 +158,7 @@ GEM
     sprockets (4.0.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
-    sprockets-rails (3.2.1)
+    sprockets-rails (3.2.2)
       actionpack (>= 4.0)
       activesupport (>= 4.0)
       sprockets (>= 3.0.0)

README.md

@@ -543,6 +543,13 @@ Yep. Use the `restart` option to resend a campaign to a user (if they are alread
 Yep. By default, Heya sends campaigns ain order of `priority`. Use the `concurrent` option to send campaigns concurrently.
 </details>
 
+## Upgrading
+Heya adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html), and
+should be considered **unstable** until version 1.0.0. Always check
+[CHANGELOG.md](./CHANGELOG.md) prior to upgrading (breaking changes will always
+be called out there). Upgrade instructions for breaking changes are in
+[UPGRADING.md](./UPGRADING.md).
+
 ## Roadmap
 See [here](https://github.com/honeybadger-io/heya/projects/1) for things we're
 considering adding to Heya.

UPGRADING.md

@@ -0,0 +1,22 @@
+# Upgrading Heya
+Heya adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html), and
+should be considered unstable until version 1.0.
+
+## 0.0.4
+If you're upgrading from Heya `<= 0.0.3`, you will need the following migration:
+
+```
+class AddStepGidToHeyaCampaignMemberships < ActiveRecord::Migration[6.0]
+  def up
+    add_column :heya_campaign_memberships, :step_gid, :string
+    Heya::CampaignMembership.migrate_next_step!
+    change_column :heya_campaign_memberships, :step_gid, :string, null: false
+  end
+
+  def down
+    remove_column :heya_campaign_memberships, :step_gid, :string
+  end
+end
+```
+
+See [CHANGELOG.md](./CHANGELOG.md) for more info.

app/models/heya/campaign_membership.rb

@@ -5,5 +5,28 @@ class CampaignMembership < ApplicationRecord
     before_create do
       self.last_sent_at = Time.now
     end
+
+    def self.migrate_next_step!
+      find_each do |membership|
+        campaign = GlobalID::Locator.locate(membership.campaign_gid)
+        receipt = campaign && CampaignReceipt.where(user: membership.user, step_gid: campaign.steps.map(&:gid)).order('created_at desc').first
+
+        next_step = if receipt
+                      last_step = GlobalID::Locator.locate(receipt.step_gid)
+                      current_index = campaign.steps.index(last_step)
+                      campaign.steps[current_index + 1]
+                    else
+                      campaign&.steps&.first
+                    end
+
+        if next_step
+          membership.update(step_gid: next_step.gid)
+        else
+          membership.destroy
+        end
+      end
+
+      CampaignReceipt.where(sent_at: nil).destroy_all
+    end
   end
 end

test/dummy/app/campaigns/first_campaign.rb

@@ -1,4 +1,5 @@
 class FirstCampaign < Heya::Campaigns::Base
   step :one, subject: "First subject"
   step :two, subject: "Second subject"
+  step :three, subject: "Third subject"
 end

test/models/heya/campaign_membership_test.rb

@@ -13,5 +13,61 @@ class CampaignMembershipTest < ActiveSupport::TestCase
 
       assert membership.last_sent_at.is_a?(Time)
     end
+
+    test ".migrate_next_step! selects first step" do
+      membership = CampaignMembership.create(
+        campaign_gid: FirstCampaign.gid,
+        step_gid: "gid://heya/null",
+        user: contacts(:one)
+      )
+
+      CampaignMembership.migrate_next_step!
+
+      assert_equal FirstCampaign.steps.first.gid, membership.reload.step_gid
+    end
+
+    test ".migrate_next_step! selects next step" do
+      membership = CampaignMembership.create(
+        campaign_gid: FirstCampaign.gid,
+        step_gid: "gid://heya/null",
+        user: contacts(:one)
+      )
+      CampaignReceipt.create(user: contacts(:one), step_gid: FirstCampaign.steps.first.gid, sent_at: Time.now)
+      CampaignReceipt.create(user: contacts(:one), step_gid: FirstCampaign.steps.second.gid, sent_at: Time.now)
+
+      assert_no_difference "CampaignReceipt.count" do
+        CampaignMembership.migrate_next_step!
+      end
+
+      assert_equal FirstCampaign.steps.third.gid, membership.reload.step_gid
+    end
+
+    test ".migrate_next_step! removes orphaned memberships" do
+      CampaignMembership.create(
+        campaign_gid: 'gid://heya/null',
+        step_gid: "gid://heya/null",
+        user: contacts(:one)
+      )
+
+      assert_difference "CampaignMembership.count", -1 do
+        CampaignMembership.migrate_next_step!
+      end
+    end
+
+    test ".migrate_next_step! removes unsent receipts" do
+      membership = CampaignMembership.create(
+        campaign_gid: FirstCampaign.gid,
+        step_gid: "gid://heya/null",
+        user: contacts(:one)
+      )
+      CampaignReceipt.create(user: contacts(:one), step_gid: FirstCampaign.steps.first.gid, sent_at: nil)
+      CampaignReceipt.create(user: contacts(:one), step_gid: FirstCampaign.steps.second.gid, sent_at: Time.now)
+
+      assert_difference "CampaignReceipt.count", -1 do
+        CampaignMembership.migrate_next_step!
+      end
+
+      assert_equal FirstCampaign.steps.third.gid, membership.reload.step_gid
+    end
   end
 end