Minor code review

assets/resources/scriptlets.js

@@ -1534,27 +1534,27 @@
 
 /// damoh-defuser.js
 (function() {
-    var handled = new WeakSet();
-    var asyncTimer;
-    var cleanVideo = function() {
+    const handled = new WeakSet();
+    let asyncTimer;
+    const cleanVideo = function() {
         asyncTimer = undefined;
-        var v = document.querySelector('video');
+        const v = document.querySelector('video');
         if ( v === null ) { return; }
         if ( handled.has(v) ) { return; }
         handled.add(v);
         v.pause();
         v.controls = true;
-        var el = v.querySelector('meta[itemprop="contentURL"][content]');
+        let el = v.querySelector('meta[itemprop="contentURL"][content]');
         if ( el === null ) { return; }
         v.src = el.getAttribute('content');
         el = v.querySelector('meta[itemprop="thumbnailUrl"][content]');
         if ( el !== null ) { v.poster = el.getAttribute('content'); }
     };
-    var cleanVideoAsync = function() {
+    const cleanVideoAsync = function() {
         if ( asyncTimer !== undefined ) { return; }
         asyncTimer = window.requestAnimationFrame(cleanVideo);
     };
-    var observer = new MutationObserver(cleanVideoAsync);
+    const observer = new MutationObserver(cleanVideoAsync);
     observer.observe(document, { childList: true, subtree: true });
 })();
 

src/js/contentscript.js

@@ -473,9 +473,7 @@ vAPI.injectScriptlet = function(doc, text) {
     } catch (ex) {
     }
     if ( script ) {
-        if ( script.parentNode ) {
-            script.parentNode.removeChild(script);
-        }
+        script.remove();
         script.textContent = '';
     }
 };
@@ -1171,11 +1169,11 @@ vAPI.DOMFilterer = class {
             //   Look-up safe-only selectors to mitigate probability of
             //   html/body elements of erroneously being targeted.
             const ids = [], classes = [];
-            if (document.documentElement !== null) {
+            if ( document.documentElement !== null ) {
                 idFromNode(document.documentElement, ids);
                 classesFromNode(document.documentElement, classes);
             }
-            if (document.body !== null) {
+            if ( document.body !== null ) {
                 idFromNode(document.body, ids);
                 classesFromNode(document.body, classes);
             }

src/js/scriptlets/dom-inspector.js

@@ -264,7 +264,7 @@ const domLayout = (function() {
                 continue;
             }
             // sibling
-            if (node instanceof Element) {
+            if ( node instanceof Element ) {
                 if ( node.nextElementSibling === null ) {
                     do {
                         node = stack.pop();
@@ -549,7 +549,7 @@ const cosmeticFilterMapper = (function() {
 
     const reset = function() {
         roRedNodes.clear();
-        if (document.documentElement !== null) {
+        if ( document.documentElement !== null ) {
             incremental(document.documentElement);
         }
     };

src/js/scriptlets/dom-survey-scripts.js

@@ -74,7 +74,9 @@
         }
     }
 
-    if ( surveyResults.scriptCount === -1 ) {
+    // https://github.com/uBlockOrigin/uBlock-issues/issues/1756
+    //   Mind that there might be no body element.
+    if ( surveyResults.scriptCount === -1 && document.body !== null ) {
         surveyResults.scriptCount = 0;
         const onHandlers = new Set([
             'onabort', 'onblur', 'oncancel', 'oncanplay',