Issue 5438 - Observer DOM changes to reapply filters.

test/browser/elemHideEmulation.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 "use strict";
 
 const {ElemHideEmulation} = require("../../lib/content/elemHideEmulation");
 
+let testDocument = null;
+
+exports.setUp = function(callback)
+{
+  testDocument = null;

[Wladimir Palant, 2017/08/23 13:23:31]

This assignment seems pointless.

[hub, 2017/08/23 16:38:00]

Done.

+  let iframe = document.createElement("iframe");
+  iframe.id = "test-iframe";
+  document.body.appendChild(iframe);
+  testDocument = iframe.contentDocument;
+
+  callback();
+};
+
 exports.tearDown = function(callback)
 {
-  let styleElements = document.head.getElementsByTagName("style");
-  while (styleElements.length)
-    styleElements[0].parentNode.removeChild(styleElements[0]);
-
-  let child;
-  while (child = document.body.firstChild)
-    child.parentNode.removeChild(child);
+  let iframe = document.getElementById("test-iframe");

[Wladimir Palant, 2017/08/23 13:23:32]

Use `testDocument.defaultView.frameElement` here? Then you won't need the frame
id either.

[hub, 2017/08/23 16:38:00]

Done.

+  iframe.parentNode.removeChild(iframe);

[Wladimir Palant, 2017/08/23 13:23:31]

Please null out testDocument as well, so that trying to use it after this point
throws.

[hub, 2017/08/23 16:38:00]

Done.

 
   callback();
 };
 
 function unexpectedError(error)
 {
   console.error(error);
   this.ok(false, "Unexpected error: " + error);
 }
 
 function expectHidden(test, element)
 {
   test.equal(window.getComputedStyle(element).display, "none",
              "The element's display property should be set to 'none'");
 }
 
 function expectVisible(test, element)
 {
   test.notEqual(window.getComputedStyle(element).display, "none",
                 "The element's display property should not be set to 'none'");
 }
 
 function findUniqueId()
 {
   let id = "elemHideEmulationTest-" + Math.floor(Math.random() * 10000);
-  if (!document.getElementById(id))
+  if (!testDocument.getElementById(id))
     return id;
   return findUniqueId();
 }
 
 function insertStyleRule(rule)
 {
   let styleElement;
-  let styleElements = document.head.getElementsByTagName("style");
+  let styleElements = testDocument.head.getElementsByTagName("style");
   if (styleElements.length)
     styleElement = styleElements[0];
   else
   {
-    styleElement = document.createElement("style");
-    document.head.appendChild(styleElement);
+    styleElement = testDocument.createElement("style");
+    testDocument.head.appendChild(styleElement);
   }
   styleElement.sheet.insertRule(rule, styleElement.sheet.cssRules.length);
 }
 
 // Insert a <div> with a unique id and a CSS rule
 // for the the selector matching the id.
 function createElementWithStyle(styleBlock, parent)
 {
-  let element = document.createElement("div");
+  let element = testDocument.createElement("div");
   element.id = findUniqueId();
   if (!parent)
-    document.body.appendChild(element);
+    testDocument.body.appendChild(element);
   else
     parent.appendChild(element);
   insertStyleRule("#" + element.id + " " + styleBlock);
   return element;
 }
 
 // Create a new ElemHideEmulation instance with @selectors.
 function applyElemHideEmulation(selectors)
 {
   return Promise.resolve().then(() =>
   {
     let elemHideEmulation = new ElemHideEmulation(
-      window,
+      testDocument.defaultView,
       callback =>
       {
         let patterns = [];
         selectors.forEach(selector =>
         {
           patterns.push({selector});
         });
         callback(patterns);
       },
       newSelectors =>
@@ skipping 233 matching lines @@
   {
     expectVisible(test, parent);
     expectVisible(test, middle);
     expectVisible(test, sibling);
     expectHidden(test, toHide);
   }).catch(unexpectedError.bind(test)).then(() => test.done());
 };
 
 function runTestPseudoClassHasSelectorWithHasAndWithSuffixSibling(test, selector, expectations)
 {
-  document.body.innerHTML = `<div id="parent">
+  testDocument.body.innerHTML = `<div id="parent">
       <div id="middle">
         <div id="middle1"><div id="inside" class="inside"></div></div>
       </div>
       <div id="sibling">
         <div id="tohide">to hide</div>
       </div>
       <div id="sibling2">
         <div id="sibling21"><div id="sibling211" class="inside"></div></div>
       </div>
     </div>`;
   let elems = {
-    parent: document.getElementById("parent"),
-    middle: document.getElementById("middle"),
-    inside: document.getElementById("inside"),
-    sibling: document.getElementById("sibling"),
-    sibling2: document.getElementById("sibling2"),
-    toHide: document.getElementById("tohide")
+    parent: testDocument.getElementById("parent"),
+    middle: testDocument.getElementById("middle"),
+    inside: testDocument.getElementById("inside"),
+    sibling: testDocument.getElementById("sibling"),
+    sibling2: testDocument.getElementById("sibling2"),
+    toHide: testDocument.getElementById("tohide")
   };
 
   insertStyleRule(".inside {}");
 
   applyElemHideEmulation(
     [selector]
   ).then(() =>
   {
     for (let elem in expectations)
       if (elems[elem])
@@ skipping 43 matching lines @@
     sibling: true,
     sibling2: true,
     toHide: true
   };
   runTestPseudoClassHasSelectorWithHasAndWithSuffixSibling(
     test, "div:-abp-has(> body div.inside) + div > div", expectations);
 };
 
 exports.testPseudoClassContains = function(test)
 {
-  document.body.innerHTML = `<div id="parent">
+  testDocument.body.innerHTML = `<div id="parent">
       <div id="middle">
         <div id="middle1"><div id="inside" class="inside"></div></div>
       </div>
       <div id="sibling">
         <div id="tohide">to hide</div>
       </div>
       <div id="sibling2">
         <div id="sibling21"><div id="sibling211" class="inside"></div></div>
       </div>
     </div>`;
-  let parent = document.getElementById("parent");
-  let middle = document.getElementById("middle");
-  let inside = document.getElementById("inside");
-  let sibling = document.getElementById("sibling");
-  let sibling2 = document.getElementById("sibling2");
-  let toHide = document.getElementById("tohide");
+  let parent = testDocument.getElementById("parent");
+  let middle = testDocument.getElementById("middle");
+  let inside = testDocument.getElementById("inside");
+  let sibling = testDocument.getElementById("sibling");
+  let sibling2 = testDocument.getElementById("sibling2");
+  let toHide = testDocument.getElementById("tohide");
 
   applyElemHideEmulation(
     ["#parent div:-abp-contains(to hide)"]
   ).then(() =>
   {
     expectVisible(test, parent);
     expectVisible(test, middle);
     expectVisible(test, inside);
     expectHidden(test, sibling);
     expectVisible(test, sibling2);
@@ skipping 20 matching lines @@
   let child = createElementWithStyle("{}", parent);
   insertStyleRule("body #" + parent.id + " > div { background-color: #000}");
   applyElemHideEmulation(
     ["div:-abp-has(:-abp-properties(background-color: rgb(0, 0, 0)))"]
   ).then(() =>
   {
     expectVisible(test, child);
     expectHidden(test, parent);
   }).catch(unexpectedError.bind(test)).then(() => test.done());
 };
+
+exports.testDomUpdatesStyle = function(test)
+{
+  let parent = createElementWithStyle("{}");
+  let child = createElementWithStyle("{}", parent);
+  applyElemHideEmulation(
+    ["div:-abp-has(:-abp-properties(background-color: rgb(0, 0, 0)))"]
+  ).then(() =>
+  {
+    expectVisible(test, child);
+    expectVisible(test, parent);
+
+    insertStyleRule("body #" + parent.id + " > div { background-color: #000}");
+
+    return new Promise((resolve, reject) =>
+    {
+      expectVisible(test, child);
+      expectVisible(test, parent);
+      window.setTimeout(() =>
+      {
+        expectVisible(test, child);
+        expectHidden(test, parent);
+        resolve();
+      }, 4000);
+    });

[Wladimir Palant, 2017/08/23 13:23:32]

Please use a helper to promisify timeouts:

  function timeout(delay)
  {
    return new Promise((resolve, reject) =>
    {
      window.setTimeout(resolve, delay);
    });
  }

Then you can write this and similar passages in a much clearer fashion:

  .then(() =>
  {
    ...
    return timeout(0);
  }).then(() =>
  {
    ...
    return timeout(4000);
  }).then(() =>
  {
    ...
  })

[hub, 2017/08/23 16:38:00]

Done.

+  }).catch(unexpectedError.bind(test)).then(() => test.done());
+};
+
+exports.testDomUpdatesContent = function(test)
+{
+  let parent = createElementWithStyle("{}");
+  let child = createElementWithStyle("{}", parent);
+  applyElemHideEmulation(
+    ["div > div:-abp-contains(hide me)"]
+  ).then(() =>
+  {
+    expectVisible(test, parent);
+    expectVisible(test, child);
+
+    child.innerText = "hide me";

[Wladimir Palant, 2017/08/23 13:23:32]

Please use child.textContent, innerText is non-standard.

[hub, 2017/08/23 16:38:00]

Done.

+    return new Promise((resolve, reject) =>
+    {
+      expectVisible(test, parent);
+      expectVisible(test, child);
+      window.setTimeout(() =>
+      {
+        expectVisible(test, parent);
+        expectHidden(test, child);
+        resolve();
+      }, 4000);
+    });
+  }).catch(unexpectedError.bind(test)).then(() => test.done());
+};
+
+exports.testDomUpdatesNewElement = function(test)
+{
+  let parent = createElementWithStyle("{}");
+  let child = createElementWithStyle("{ background-color: #000}", parent);
+  applyElemHideEmulation(
+    ["div:-abp-has(:-abp-properties(background-color: rgb(0, 0, 0)))"]
+  ).then(() =>
+  {
+    expectHidden(test, parent);
+    expectVisible(test, child);
+
+    let sibling = createElementWithStyle("{}");
+    expectVisible(test, sibling);
+
+    return new Promise((resolve, reject) =>
+    {
+      expectHidden(test, parent);
+      expectVisible(test, child);
+      expectVisible(test, sibling);
+      window.setTimeout(() =>
+      {
+        expectHidden(test, parent);
+        expectVisible(test, child);
+        expectVisible(test, sibling);
+
+        let child2 = createElementWithStyle("{ background-color: #000}",
+                                            sibling);
+        expectVisible(test, child2);
+        window.setTimeout(() =>
+        {
+          expectHidden(test, parent);
+          expectVisible(test, child);
+          expectHidden(test, sibling);
+          expectVisible(test, child2);
+
+          resolve();
+        }, 4000);
+      }, 4000);

[Wladimir Palant, 2017/08/23 13:23:32]

The huge delays here are an issue. We need to change MIN_INVOCATION_INTERVAL for
unit tests to a much lower value, like 100. Not sure what the best approach for
this would be, maybe string-replace-webpack-plugin?

[hub, 2017/08/23 16:38:00]

IMHO the best approach would be to have it configurable in elemHideEmulation.
This would be clean, and we could also have the possibility to make that a
preference for a reason or the other.

Done.

+    });
+  }).catch(unexpectedError.bind(test)).then(() => test.done());
+};