statsd instrumentation for animated gif shrinker

config/initializers/statsd.rb

@@ -20,6 +20,12 @@
 GendImageProcessJob.statsd_count_success(:perform, 'job.gend_image.process')
 GendImageProcessJob.statsd_measure(:perform, 'job.gend_image.process.time')
 
+MemeCaptainWeb::AnimatedGifShrinker.extend(StatsD::Instrument)
+MemeCaptainWeb::AnimatedGifShrinker.statsd_count_success(
+  :shrink, 'animated_gif_shrinker.shrink')
+MemeCaptainWeb::AnimatedGifShrinker.statsd_measure(
+  :shrink, 'animated_gif_shrinker.shrink.runtime')
+
 SrcImageNameJob.extend(StatsD::Instrument)
 SrcImageNameJob.statsd_measure(:perform, 'job.src_image.name.time')
 

spec/classes/meme_captain_web/animated_gif_shrinker_spec.rb

@@ -1,6 +1,8 @@
 require 'rails_helper'
 
 describe MemeCaptainWeb::AnimatedGifShrinker do
+  include StatsD::Instrument::Matchers
+
   subject(:animated_gif_shrinker) do
     MemeCaptainWeb::AnimatedGifShrinker.new(coalescer, trimmer)
   end
@@ -55,6 +57,26 @@
           animated_gif_shrinker.shrink(image_data, max_size) {}
         ).to be_nil
       end
+
+      it 'increments the statsd success counter' do
+        allow(coalescer).to receive(:coalesce).with('GIFdata').and_return(
+          'GIFdatacoalesced')
+        allow(trimmer).to receive(:trim).with('GIFdatacoalesced').and_return(
+          'x')
+        expect do
+          animated_gif_shrinker.shrink(image_data, max_size) {}
+        end.to trigger_statsd_increment('animated_gif_shrinker.shrink.success')
+      end
+
+      it 'sends a statsd time measurement' do
+        allow(coalescer).to receive(:coalesce).with('GIFdata').and_return(
+          'GIFdatacoalesced')
+        allow(trimmer).to receive(:trim).with('GIFdatacoalesced').and_return(
+          'x')
+        expect do
+          animated_gif_shrinker.shrink(image_data, max_size) {}
+        end.to trigger_statsd_measure('animated_gif_shrinker.shrink.runtime')
+      end
     end
 
     context 'when multiple passes are required' do
@@ -83,5 +105,25 @@
         ). to be_nil
       end
     end
+
+    context 'when shrinking raises an exception' do
+      let(:image_data) { 'GIFdata' }
+      let(:max_size) { 4 }
+
+      before do
+        expect(coalescer).to receive(:coalesce).with('GIFdata').and_raise(
+          'error')
+      end
+
+      it 'increments the statsd failure counter' do
+        expect do
+          begin
+            animated_gif_shrinker.shrink(image_data, max_size) {}
+          rescue StandardError => e
+            e
+          end
+        end.to trigger_statsd_increment('animated_gif_shrinker.shrink.failure')
+      end
+    end
   end
 end