Write task to migrate budget admins and valuators

If we didn't run this task, investments for existing budgets wouldn't
show their administrator/valuators as an option when we're editing them,
leading to data loss.

lib/tasks/consul.rake

@@ -5,6 +5,7 @@ namespace :consul do
   desc "Runs tasks needed to upgrade from 1.0.0 to 1.1.0"
   task "execute_release_1.1.0_tasks": [
     "budgets:set_original_heading_id",
-    "migrations:valuation_taggings"
+    "migrations:valuation_taggings",
+    "migrations:budget_admins_and_valuators"
   ]
 end

lib/tasks/migrations.rake

@@ -4,4 +4,17 @@ namespace :migrations do
     ApplicationLogger.new.info "Updating valuation taggings context"
     Tagging.where(context: "valuation").update_all(context: "valuation_tags")
   end
+
+  desc "Migrates budget staff"
+  task budget_admins_and_valuators: :environment do
+    ApplicationLogger.new.info "Updating budget administrators and valuators"
+    Budget.find_each do |budget|
+      investments = budget.investments.with_hidden
+
+      budget.update!(
+        administrator_ids: investments.where.not(administrator: nil).distinct.pluck(:administrator_id),
+        valuator_ids: Budget::ValuatorAssignment.where(investment: investments).distinct.pluck(:valuator_id)
+      )
+    end
+  end
 end

spec/lib/tasks/migrations_spec.rb

@@ -1,6 +1,7 @@
 require "rails_helper"
 
 describe "Migration tasks" do
+  describe "valuation_taggins" do
     let(:run_rake_task) do
       Rake::Task["migrations:valuation_taggings"].reenable
       Rake.application.invoke_task("migrations:valuation_taggings")
@@ -19,4 +20,49 @@ describe "Migration tasks" do
       expect(valuation_tags_tagging.reload.context).to eq "valuation_tags"
       expect(tags_tagging.reload.context).to eq "tags"
     end
+  end
+
+  describe "budget_admins_and_valuators" do
+    let(:run_rake_task) do
+      Rake::Task["migrations:budget_admins_and_valuators"].reenable
+      Rake.application.invoke_task("migrations:budget_admins_and_valuators")
+    end
+
+    let(:old_budget) { create(:budget) }
+    let(:current_budget) { create(:budget) }
+
+    it "assigns administrators from existing investments" do
+      harold = create(:administrator)
+      john = create(:administrator)
+      root = create(:administrator)
+
+      create(:budget_investment, budget: old_budget, administrator: john)
+      create(:budget_investment, budget: old_budget, administrator: harold)
+      create(:budget_investment, budget: old_budget, administrator: nil)
+
+      create(:budget_investment, budget: current_budget, administrator: root)
+
+      run_rake_task
+
+      expect(old_budget.administrators).to match_array [john, harold]
+      expect(current_budget.administrators).to match_array [root]
+    end
+
+    it "assigns valuators from existing investments" do
+      tyrion = create(:valuator)
+      cersei = create(:valuator)
+      jaime = create(:valuator)
+
+      create(:budget_investment, budget: old_budget, valuators: [cersei])
+      create(:budget_investment, budget: old_budget, valuators: [jaime, cersei])
+      create(:budget_investment, budget: old_budget, valuators: [])
+
+      create(:budget_investment, budget: current_budget, valuators: [tyrion, jaime])
+
+      run_rake_task
+
+      expect(old_budget.valuators).to match_array [cersei, jaime]
+      expect(current_budget.valuators).to match_array [tyrion, jaime]
+    end
+  end
 end