Only allow same origin (domain + subdomains) for preload

GoogleChrome · Apr 29, 2018 · 32a4b20 · 32a4b20
1 parent b150d71
commit 32a4b20
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Showing 3 changed files with 63 additions and 13 deletions.
diff --git a/lighthouse-core/audits/uses-rel-preload.js b/lighthouse-core/audits/uses-rel-preload.js
@@ -8,6 +8,7 @@
 
 const Audit = require('./audit');
 const Util = require('../report/v2/renderer/util');
+const URL = require('../lib/url-shim');
 const UnusedBytes = require('./byte-efficiency/byte-efficiency-audit');
 const THRESHOLD_IN_MS = 100;
 
@@ -51,8 +52,22 @@ class UsesRelPreloadAudit extends Audit {
   }
 
   /**
-   * @param {!Artifacts} artifacts
-   * @return {!AuditResult}
+   *
+   * @param {LH.WebInspector.NetworkRequest} request
+   * @param {LH.WebInspector.NetworkRequest} mainResource
+   * @return {boolean}
+   */
+  static shouldPreload(request, mainResource) {
+    if (request._isLinkPreload || request.protocol === 'data') {
+      return false;
+    }
+
+    return URL.rootDomainsMatch(request.url, mainResource.url);
+  }
+
+  /**
+   * @param {LH.Artifacts} artifacts
+   * @return {LH.Audit.Product}
    */
   static audit(artifacts) {
     const devtoolsLogs = artifacts.devtoolsLogs[UsesRelPreloadAudit.DEFAULT_PASS];
@@ -63,14 +78,13 @@ class UsesRelPreloadAudit extends Audit {
     ]).then(([critChains, mainResource]) => {
       const results = [];
       let maxWasted = 0;
-      // get all critical requests 2 + mainResourceIndex levels deep
+      // get all critical requests 2 levels deep (starting from mainResource index)
       const mainResourceIndex = mainResource.redirects ? mainResource.redirects.length : 0;
 
       const criticalRequests = UsesRelPreloadAudit._flattenRequests(critChains,
         3 + mainResourceIndex, 2 + mainResourceIndex);
       criticalRequests.forEach(request => {
-        const networkRecord = request;
-        if (!networkRecord._isLinkPreload && networkRecord.protocol !== 'data') {
+        if (UsesRelPreloadAudit.shouldPreload(request, mainResource)) {
           // calculate time between mainresource.endTime and resource start time
           const wastedMs = Math.min(request._startTime - mainResource._endTime,
             request._endTime - request._startTime) * 1000;

diff --git a/lighthouse-core/lib/url-shim.js b/lighthouse-core/lib/url-shim.js
@@ -87,6 +87,26 @@ class URLShim extends URL {
     }
   }
 
+  /**
+   * Check if rootDomains matches
+   *
+   * @param {string} urlA
+   * @param {string} urlB
+   */
+  static rootDomainsMatch(urlA, urlB) {
+    const urlAInfo = new URL(urlA);
+    const urlBInfo = new URL(urlB);
+
+    if (!urlAInfo.host || !urlBInfo.host) {
+      return false;
+    }
+
+    const urlARootDomain = urlAInfo.host.split('.').slice(-2).join('.');
+    const urlBRootDomain = urlBInfo.host.split('.').slice(-2).join('.');
+
+    return urlARootDomain === urlBRootDomain;
+  }
+
   /**
    * @param {string} url
    * @param {{numPathParts: number, preserveQuery: boolean, preserveHost: boolean}=} options

diff --git a/lighthouse-core/test/audits/uses-rel-preload-test.js b/lighthouse-core/test/audits/uses-rel-preload-test.js
@@ -11,6 +11,7 @@
 const UsesRelPreload = require('../../audits/uses-rel-preload.js');
 const assert = require('assert');
 const defaultMainResource = {
+  url: 'http://www.example.com',
   _endTime: 1,
 };
 
@@ -37,16 +38,24 @@ describe('Performance: uses-rel-preload audit', () => {
     const networkRecords = [
       {
         requestId: '2',
-        _endTime: 1,
+        _startTime: 10,
+        _endTime: 19,
         _isLinkPreload: false,
-        _url: 'http://www.example.com',
+        url: 'http://www.example.com/script.js',
       },
       {
         requestId: '3',
-        _startTime: 10,
-        _endTime: 19,
+        _startTime: 7,
+        _endTime: 17,
+        _isLinkPreload: false,
+        url: 'http://sub.example.com/secondary_script.js',
+      },
+      {
+        requestId: '4',
+        _startTime: 7,
+        _endTime: 17,
         _isLinkPreload: false,
-        _url: 'http://www.example.com/script.js',
+        url: 'http://otherdomain.com/terniary_script.js',
       },
     ];
     const chains = {
@@ -55,12 +64,19 @@ describe('Performance: uses-rel-preload audit', () => {
           '2': {
             children: {
               '3': {
-                request: networkRecords[0],
                 children: {
                   '4': {
+                    request: networkRecords[0],
+                    children: {},
+                  },
+                  '5': {
                     request: networkRecords[1],
                     children: {},
                   },
+                  '6': {
+                    request: networkRecords[2],
+                    children: {},
+                  },
                 },
               },
             },
@@ -72,7 +88,7 @@ describe('Performance: uses-rel-preload audit', () => {
     return UsesRelPreload.audit(mockArtifacts(networkRecords, chains, mainResource))
       .then(output => {
         assert.equal(output.rawValue, 9000);
-        assert.equal(output.details.items.length, 1);
+        assert.equal(output.details.items.length, 2);
       });
   });
 
@@ -82,7 +98,7 @@ describe('Performance: uses-rel-preload audit', () => {
         requestId: '3',
         _startTime: 10,
         _isLinkPreload: true,
-        _url: 'http://www.example.com/script.js',
+        url: 'http://www.example.com/script.js',
       },
     ];
     const chains = {