From 8acc39581cfa4e13e4516cdf64bee0452422b47d Mon Sep 17 00:00:00 2001
From: Raymond Hill <rhill@raymondhill.net>
Date: Fri, 1 Nov 2019 14:28:15 -0400
Subject: [PATCH] Fine tune script tags survey scriptlet

Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/756

The code used to count expensive-to-survey particular
inline javascript occurrences will be executed if and
only if no other script tags have been found in the
DOM. This is acceptable since the badge count is to be
deemed approximate (as per documentation).
---
 src/js/scriptlets/dom-survey-scripts.js | 37 +++++++++++--------------
 1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/src/js/scriptlets/dom-survey-scripts.js b/src/js/scriptlets/dom-survey-scripts.js
index 17698333a..8d0a123df 100644
--- a/src/js/scriptlets/dom-survey-scripts.js
+++ b/src/js/scriptlets/dom-survey-scripts.js
@@ -29,13 +29,11 @@
     if ( typeof vAPI !== 'object' ) { return; }
 
     const t0 = Date.now();
-    const tMax = t0 + 50;
 
     if ( vAPI.domSurveyScripts instanceof Object === false ) {
         vAPI.domSurveyScripts = {
             busy: false,
-            inlineScriptCount: -1,
-            externalScriptCount: -1,
+            scriptCount: -1,
             surveyTime: t0,
         };
     }
@@ -45,40 +43,39 @@
     surveyResults.busy = true;
 
     if ( surveyResults.surveyTime < vAPI.domMutationTime ) {
-        surveyResults.inlineScriptCount = -1;
-        surveyResults.externalScriptCount = -1;
+        surveyResults.scriptCount = -1;
     }
     surveyResults.surveyTime = t0;
 
-    if ( surveyResults.externalScriptCount === -1 ) {
+    if ( surveyResults.scriptCount === -1 ) {
         const reInlineScript = /^(data:|blob:|$)/;
         let inlineScriptCount = 0;
-        let externalScriptCount = 0;
+        let scriptCount = 0;
         for ( const script of document.scripts ) {
             if ( reInlineScript.test(script.src) ) {
                 inlineScriptCount = 1;
                 continue;
             }
-            externalScriptCount += 1;
-            if ( externalScriptCount === 99 ) { break; }
+            scriptCount += 1;
+            if ( scriptCount === 99 ) { break; }
         }
-        if ( inlineScriptCount !== 0 || externalScriptCount === 99 ) {
-            surveyResults.inlineScriptCount = inlineScriptCount;
+        scriptCount += inlineScriptCount;
+        if ( scriptCount !== 0 ) {
+            surveyResults.scriptCount = scriptCount;
         }
-        surveyResults.externalScriptCount = externalScriptCount;
     }
 
     // https://github.com/uBlockOrigin/uBlock-issues/issues/756
     //   Keep trying to find inline script-like instances but only if we
     //   have the time-budget to do so.
-    if ( surveyResults.inlineScriptCount === -1 && Date.now() < tMax ) {
+    if ( surveyResults.scriptCount === -1 ) {
         if ( document.querySelector('a[href^="javascript:"]') !== null ) {
-            surveyResults.inlineScriptCount = 1;
+            surveyResults.scriptCount = 1;
         }
     }
 
-    if ( surveyResults.inlineScriptCount === -1 && Date.now() < tMax ) {
-        surveyResults.inlineScriptCount = 0;
+    if ( surveyResults.scriptCount === -1 ) {
+        surveyResults.scriptCount = 0;
         const onHandlers = new Set([
             'onabort', 'onblur', 'oncancel', 'oncanplay',
             'oncanplaythrough', 'onchange', 'onclick', 'onclose',
@@ -111,7 +108,7 @@
             if ( node.hasAttributes() === false ) { continue; }
             for ( const attr of node.getAttributeNames() ) {
                 if ( onHandlers.has(attr) === false ) { continue; }
-                surveyResults.inlineScriptCount = 1;
+                surveyResults.scriptCount = 1;
                 break;
             }
         }
@@ -121,9 +118,7 @@
 
     // IMPORTANT: This is returned to the injector, so this MUST be
     //            the last statement.
-    let total = surveyResults.externalScriptCount;
-    if ( surveyResults.inlineScriptCount !== -1 ) {
-        total += surveyResults.inlineScriptCount;
+    if ( surveyResults.scriptCount !== -1 ) {
+        return surveyResults.scriptCount;
     }
-    return total;
 })();