From 82505a157b4c2f0acfedba777b274ebdfed878bb Mon Sep 17 00:00:00 2001
From: Ward Peeters <ward@coding-tech.com>
Date: Wed, 11 Jul 2018 18:45:39 +0200
Subject: [PATCH] core(preload): remove blob protocol from preload audit
 (#5409)

---
 lighthouse-core/audits/uses-rel-preload.js    |  2 +-
 lighthouse-core/lib/url-shim.js               |  2 ++
 .../test/audits/uses-rel-preload-test.js      | 30 +++++++++++++++++++
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/lighthouse-core/audits/uses-rel-preload.js b/lighthouse-core/audits/uses-rel-preload.js
index 6e49d1038576..8622629d7d6d 100644
--- a/lighthouse-core/audits/uses-rel-preload.js
+++ b/lighthouse-core/audits/uses-rel-preload.js
@@ -65,7 +65,7 @@ class UsesRelPreloadAudit extends Audit {
    * @return {boolean}
    */
   static shouldPreload(request, mainResource) {
-    if (request.isLinkPreload || request.protocol === 'data') {
+    if (request.isLinkPreload || URL.NON_NETWORK_PROTOCOLS.includes(request.protocol)) {
       return false;
     }
 
diff --git a/lighthouse-core/lib/url-shim.js b/lighthouse-core/lib/url-shim.js
index 78ee0fbbe979..aaeb79ea7651 100644
--- a/lighthouse-core/lib/url-shim.js
+++ b/lighthouse-core/lib/url-shim.js
@@ -190,6 +190,8 @@ URLShim.URL = URL;
 URLShim.URLSearchParams = (typeof self !== 'undefined' && self.URLSearchParams) ||
     require('url').URLSearchParams;
 
+URLShim.NON_NETWORK_PROTOCOLS = ['blob', 'data'];
+
 URLShim.INVALID_URL_DEBUG_STRING =
     'Lighthouse was unable to determine the URL of some script executions. ' +
     'It\'s possible a Chrome extension or other eval\'d code is the source.';
diff --git a/lighthouse-core/test/audits/uses-rel-preload-test.js b/lighthouse-core/test/audits/uses-rel-preload-test.js
index 4ab841a96363..ab41e062d269 100644
--- a/lighthouse-core/test/audits/uses-rel-preload-test.js
+++ b/lighthouse-core/test/audits/uses-rel-preload-test.js
@@ -232,6 +232,36 @@ describe('Performance: uses-rel-preload audit', () => {
     });
   });
 
+  it(`shouldn't suggest preload for protocol blob`, () => {
+    const networkRecords = [
+      {
+        requestId: '3',
+        protocol: 'blob',
+        _startTime: 10,
+      },
+    ];
+
+    const chains = {
+      '1': {
+        children: {
+          '2': {
+            children: {
+              '3': {
+                request: networkRecords[0],
+                children: {},
+              },
+            },
+          },
+        },
+      },
+    };
+
+    return UsesRelPreload.audit(mockArtifacts(networkRecords, chains), {}).then(output => {
+      assert.equal(output.rawValue, 0);
+      assert.equal(output.details.items.length, 0);
+    });
+  });
+
   it('does not throw on a real trace/devtools log', async () => {
     const artifacts = Object.assign({
       URL: {finalUrl: 'https://pwa.rocks/'},