Add rake task to export form counts to CloudWatch

Provides metrics:export_form_counts for scheduled publishing of form
count metrics via FormCountService.

Author: theseanything

lib/tasks/metrics.rake

@@ -0,0 +1,6 @@
+namespace :metrics do
+  desc "Export form counts to CloudWatch metrics grouped by organisation and state"
+  task export_form_counts: :environment do
+    Metrics::FormCountService.new.publish_form_counts
+  end
+end

spec/lib/tasks/metrics.rake_spec.rb

@@ -0,0 +1,17 @@
+require "rails_helper"
+
+RSpec.describe "metrics.rake", type: :task do
+  describe "metrics:export_form_counts" do
+    subject(:task) do
+      Rake::Task["metrics:export_form_counts"]
+    end
+
+    it "publishes form counts via Metrics::FormCountService" do
+      service = instance_double(Metrics::FormCountService)
+      allow(Metrics::FormCountService).to receive(:new).and_return(service)
+      expect(service).to receive(:publish_form_counts)
+
+      task.invoke
+    end
+  end
+end