Issue 7236 - Handle sub properties in abort-on-property snippets

test/browser/snippets.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 library = require("../../lib/content/snippets.js");
+const {timeout} = require("./_utils");
 
 // We need this stub for the injector.
-window.browser =
-{
-  runtime:
-  {
+window.browser = {
+  runtime: {
     getURL: () => ""
   }
 };
-
-let testDocument = null;
-
-exports.setUp = function(callback)
-{
-  let iframe = document.createElement("iframe");
-  document.body.appendChild(iframe);
-  testDocument = iframe.contentDocument;
-
-  callback();
-};
-
-exports.tearDown = function(callback)
-{
-  let iframe = testDocument.defaultView.frameElement;
-  iframe.parentNode.removeChild(iframe);
-  testDocument = null;
-
-  callback();
-};
-
-function timeout(delay)
-{
-  return new Promise((resolve, reject) =>
-  {
-    window.setTimeout(resolve, delay);
-  });
-}
 
 async function runSnippet(test, snippetName, ...args)
 {
   let snippet = library[snippetName];
 
   test.ok(snippet);
 
   snippet(...args);
+
+  // For snippets that run in the context of the document via a <script>
+  // element (i.e. snippets that use makeInjector()), we need to wait for
+  // execution to be complete.
   await timeout(100);
 }
 
-exports.testSnippet = async function(test)
+exports.testAbortOnPropertyReadSnippet = async function(test)
 {
-  window.abpTest = "foo";
-
-  async function testProperty(property, result = true)
+  function testProperty(property, result = true, errorName = "ReferenceError")
   {
-    let properties = property.split(".");
-    test.ok(properties.length >= 1);
+    let path = property.split(".");
 
     let exceptionCaught = false;
     let value = 1;
+
     try
     {
       let obj = window;
-      while (properties.length > 1)
-        obj = obj[properties.shift()];
-      value = obj[properties.shift()];
+      while (path.length > 1)
+        obj = obj[path.shift()];
+      value = obj[path.shift()];
     }
     catch (e)
     {
-      if (properties.length == 0)
-        exceptionCaught = true;
+      test.equal(e.name, errorName);
+      exceptionCaught = true;
     }
-    test.equal(exceptionCaught, result, `The property "${property}" didn't trigger and exception.`);
-    test.equal(value, result ? 1 : undefined, `The value for "${property}" shouldn't have been read.`);
+
+    test.equal(
+      exceptionCaught,
+      result,
+      `The property "${property}" ${result ? "should" : "shouldn't"} trigger an exception.`
+    );
+    test.equal(
+      value,
+      result ? 1 : undefined,
+      `The value for "${property}" ${result ? "shouldn't" : "should"} have been read.`
+    );
   }
 
+  window.abpTest = "fortytwo";
   await runSnippet(test, "abort-on-property-read", "abpTest");
-  await testProperty("abpTest");
+  testProperty("abpTest");
 
-  window.abpTest2 = {prop1: "foo"};
+  window.abpTest2 = {prop1: "fortytwo"};
+  await runSnippet(test, "abort-on-property-read", "abpTest2.prop1");
+  testProperty("abpTest2.prop1");
 
-  await runSnippet(test, "abort-on-property-read", "abpTest2.prop1");
-  await testProperty("abpTest2.prop1");
-
-  // Test that we try to catch a property that don't exist yet.
+  // Test that we try to catch a property that doesn't exist yet.
   await runSnippet(test, "abort-on-property-read", "abpTest3.prop1");
-  window.abpTest3 = {prop1: "foo"};
-  await testProperty("abpTest3.prop1");
+  window.abpTest3 = {prop1: "fortytwo"};
+  testProperty("abpTest3.prop1");
 
   // Test that other properties don't trigger.
-  await testProperty("abpTest3.prop2", false);
+  testProperty("abpTest3.prop2", false);
+
+  // Test overwriting the object with another object.
+  window.abpTest4 = {prop3: {}};
+  await runSnippet(test, "abort-on-property-read", "abpTest4.prop3.foo");
+  testProperty("abpTest4.prop3.foo");
+  window.abpTest4.prop3 = {};
+  testProperty("abpTest4.prop3.foo");
+
+  // Test if we start with a non-object.
+  window.abpTest5 = 42;
+  await runSnippet(test, "abort-on-property-read", "abpTest5.prop4.bar");
+
+  testProperty("abpTest5.prop4.bar", true, "TypeError");
+
+  window.abpTest5 = {prop4: 42};
+  testProperty("abpTest5.prop4.bar", false);
+  window.abpTest5 = {prop4: {}};
+  testProperty("abpTest5.prop4.bar");
 
   test.done();
 };