From 3d0b9ee97d44d8db4bc1e9298be0d6574ac49523 Mon Sep 17 00:00:00 2001
From: Patrick Hulce <patrick.hulce@gmail.com>
Date: Wed, 13 Dec 2017 11:02:20 -0800
Subject: [PATCH] core(optimized-images): skip mismatched mimeTypes

---
 .../gatherers/dobetterweb/optimized-images.js     |  4 +++-
 .../dobetterweb/optimized-images-test.js          | 15 +++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/lighthouse-core/gather/gatherers/dobetterweb/optimized-images.js b/lighthouse-core/gather/gatherers/dobetterweb/optimized-images.js
index aebc1ac0ad20..4b70729675c8 100644
--- a/lighthouse-core/gather/gatherers/dobetterweb/optimized-images.js
+++ b/lighthouse-core/gather/gatherers/dobetterweb/optimized-images.js
@@ -73,7 +73,9 @@ class OptimizedImages extends Gatherer {
       }
 
       seenUrls.add(record._url);
-      const isOptimizableImage = /image\/(png|bmp|jpeg)/.test(record._mimeType);
+      const isOptimizableImage = record._resourceType &&
+        record._resourceType._name === 'image' &&
+        /image\/(png|bmp|jpeg)/.test(record._mimeType);
       const isSameOrigin = URL.originsMatch(pageUrl, record._url);
       const isBase64DataUri = /^data:.{2,40}base64\s*,/.test(record._url);
 
diff --git a/lighthouse-core/test/gather/gatherers/dobetterweb/optimized-images-test.js b/lighthouse-core/test/gather/gatherers/dobetterweb/optimized-images-test.js
index dba919408512..a725331c95be 100644
--- a/lighthouse-core/test/gather/gatherers/dobetterweb/optimized-images-test.js
+++ b/lighthouse-core/test/gather/gatherers/dobetterweb/optimized-images-test.js
@@ -23,50 +23,65 @@ const traceData = {
       _url: 'http://google.com/image.jpg',
       _mimeType: 'image/jpeg',
       _resourceSize: 10000,
+      _resourceType: {_name: 'image'},
       finished: true,
     },
     {
       _url: 'http://google.com/transparent.png',
       _mimeType: 'image/png',
       _resourceSize: 11000,
+      _resourceType: {_name: 'image'},
       finished: true,
     },
     {
       _url: 'http://google.com/image.bmp',
       _mimeType: 'image/bmp',
       _resourceSize: 12000,
+      _resourceType: {_name: 'image'},
       finished: true,
     },
     {
       _url: 'http://google.com/image.bmp',
       _mimeType: 'image/bmp',
       _resourceSize: 12000,
+      _resourceType: {_name: 'image'},
       finished: true,
     },
     {
       _url: 'http://google.com/vector.svg',
       _mimeType: 'image/svg+xml',
       _resourceSize: 13000,
+      _resourceType: {_name: 'image'},
       finished: true,
     },
     {
       _url: 'http://gmail.com/image.jpg',
       _mimeType: 'image/jpeg',
       _resourceSize: 15000,
+      _resourceType: {_name: 'image'},
       finished: true,
     },
     {
       _url: 'data: image/jpeg ; base64 ,SgVcAT32587935321...',
       _mimeType: 'image/jpeg',
+      _resourceType: {_name: 'image'},
       _resourceSize: 14000,
       finished: true,
     },
     {
       _url: 'http://google.com/big-image.bmp',
       _mimeType: 'image/bmp',
+      _resourceType: {_name: 'image'},
       _resourceSize: 12000,
       finished: false, // ignore for not finishing
     },
+    {
+      _url: 'http://google.com/not-an-image.bmp',
+      _mimeType: 'image/bmp',
+      _resourceType: {_name: 'document'}, // ignore for not really being an image
+      _resourceSize: 12000,
+      finished: true,
+    },
   ],
 };