feat(scripts): improve code structure and performance

scripts/background.js

@@ -101,6 +101,54 @@ const getCache = (hostname, responseCallback) => {
   });
 };
 
+/**
+ * @async
+ * @function getClasses
+ * @description Retrieves a selectors list
+ *
+ * @param {void} [responseCallback]
+ * @returns {Promise<{ matches: string[] }>} A selectors list
+ */
+
+const getClasses = async (responseCallback) => {
+  try {
+    const url =
+      "https://raw.githubusercontent.com/wanhose/do-not-consent/master/data/classes.txt";
+    const response = await fetch(url);
+    const data = await response.text();
+
+    if (response.status !== 200) throw new Error();
+
+    responseCallback({ classes: data.split("\n") });
+  } catch {
+    responseCallback({ classes: [] });
+  }
+};
+
+/**
+ * @async
+ * @function getSelectors
+ * @description Retrieves a selectors list
+ *
+ * @param {void} [responseCallback]
+ * @returns {Promise<{ matches: string[] }>} A selectors list
+ */
+
+const getSelectors = async (responseCallback) => {
+  try {
+    const url =
+      "https://raw.githubusercontent.com/wanhose/do-not-consent/master/data/elements.txt";
+    const response = await fetch(url);
+    const data = await response.text();
+
+    if (response.status !== 200) throw new Error();
+
+    responseCallback({ selectors: data.split("\n") });
+  } catch {
+    responseCallback({ selectors: [] });
+  }
+};
+
 /**
  * @function getTab
  * @description Retrieves current tab information
@@ -118,30 +166,6 @@ const getTab = (responseCallback) => {
   });
 };
 
-/**
- * @async
- * @function getList
- * @description Retrieves selectors list
- *
- * @param {void} [responseCallback]
- * @returns {Promise<{ matches: string[] }>} A selectors list
- */
-
-const getList = async (responseCallback) => {
-  try {
-    const url =
-      "https://raw.githubusercontent.com/wanhose/do-not-consent/master/data/elements.txt";
-    const response = await fetch(url);
-    const data = await response.text();
-
-    if (response.status !== 200) throw new Error();
-
-    responseCallback({ selectors: data.split("\n") });
-  } catch {
-    responseCallback({ selectors: [] });
-  }
-};
-
 /**
  * @function updateCache
  * @description Update cache state
@@ -200,8 +224,11 @@ chrome.runtime.onMessage.addListener((request, sender, responseCallback) => {
     case "GET_CACHE":
       getCache(request.hostname, responseCallback);
       break;
-    case "GET_LIST":
+    case "GET_CLASSES":
-      getList(responseCallback);
+      getClasses(responseCallback);
+      break;
+    case "GET_SELECTORS":
+      getSelectors(responseCallback);
       break;
     case "GET_TAB":
       getTab(responseCallback);

scripts/content.js

@@ -1,5 +1,4 @@
 /**
- * @var attempts
  * @description Number of attempts
  * @type {number}
  */
@@ -7,7 +6,13 @@
 let attempts = 1;
 
 /**
- * @constant dispatch
+ * @description Array of selectors
+ * @type {string[]}
+ */
+
+let classesFromNetwork = [];
+
+/**
  * @description Shortcut to send messages to background script
  * @type {void}
  */
@@ -15,15 +20,6 @@ let attempts = 1;
 const dispatch = chrome.runtime.sendMessage;
 
 /**
- * @var intervalId
- * @description Task interval identifier
- * @type {number}
- */
-
-let intervalId = 0;
-
-/**
- * @var selectorsFromCache
  * @description Array of selectors
  * @type {string[]}
  */
@@ -31,30 +27,92 @@ let intervalId = 0;
 let selectorsFromCache = [];
 
 /**
- * @var selectorsFromNetwork
  * @description Array of selectors
- * @type {string[]}
+ * @type {Promise<string[]>[]}
  */
 
 let selectorsFromNetwork = [];
 
 /**
- * @function fix
+ * @description Split large arrays into promises
- * @description Fix scroll issues
+ * @param {string[]} array
+ */
+
+const chunkerize = (array) =>
+  [...Array(Math.ceil(array.length / 300))].map(
+    (_, index) => () =>
+      new Promise((resolve) => {
+        removeElements(array.slice(index * 300, (index + 1) * 300), true);
+        resolve(true);
+      })
+  );
+
+/**
+ * @description Fixes scroll issues
  */
 
 const fix = () => {
   const body = document.body;
-  const classListToRemove = ["ta-cc-modal-open"];
+  const classes = classesFromNetwork;
   const facebook = document.getElementsByClassName("_31e")[0];
   const html = document.documentElement;
 
-  if (body) body.classList.remove(...classListToRemove);
+  if (body && classes.length > 0) body.classList.remove(...classes);
   if (body) body.style.setProperty("overflow-y", "unset", "important");
   if (facebook) facebook.style.setProperty("position", "unset", "important");
   if (html) html.style.setProperty("overflow-y", "unset", "important");
 };
 
+/**
+ * @function removeElements
+ * @description Removes matched elements from a selectors array
+ * @param {string[]} selectors
+ * @param {boolean} updateCache
+ */
+
+const removeElements = (selectors, updateCache) => {
+  for (let i = selectors.length; i--; ) {
+    const selector = selectors[i];
+    const element = search(selector);
+
+    if (element) {
+      const tagName = element.tagName.toUpperCase();
+
+      if (!["BODY", "HTML"].includes(tagName)) {
+        element.remove();
+
+        if (updateCache) {
+          selectorsFromCache = [...selectorsFromCache, selector];
+          dispatch({
+            hostname: document.location.hostname,
+            state: { matches: [selector] },
+            type: "UPDATE_CACHE",
+          });
+        }
+      }
+    }
+  }
+};
+
+/**
+ * @function runTasks
+ * @description Starts running tasks
+ */
+
+const runTasks = async () => {
+  if (attempts <= 20) {
+    fix();
+    removeElements(selectorsFromCache);
+
+    if (selectorsFromNetwork.length > 0) {
+      const selectors = selectorsFromNetwork;
+
+      if (attempts <= 5) await Promise.all(selectors.map((fn) => fn()));
+      if (document.readyState === "complete") attempts += 1;
+    }
+  }
+};
+
 /**
  * @function search
  * @description Retrieves HTML element if selector exists
@@ -80,83 +138,40 @@ const search = (selector) => {
 };
 
 /**
- * @function removeFromCache
+ * @description Setups classes selectors
- * @description Removes matched elements from cache results
+ * @type {Promise<boolean>}
  */
 
-const removeFromCache = () => {
+const setupClasses = new Promise((resolve) => {
-  for (let i = selectorsFromCache.length; i--; ) {
+  dispatch({ type: "GET_CLASSES" }, null, ({ classes }) => {
-    const selector = selectorsFromCache[i];
+    classesFromNetwork = classes;
-    const element = search(selector);
+    resolve(true);
-
+  });
-    if (element) {
-      const tagName = element.tagName.toUpperCase();
-
-      if (!["BODY", "HTML"].includes(tagName)) element.remove();
-    }
-  }
-};
-
-/**
- * @function removeFromNetwork
- * @description Removes matched elements from network results
- */
-
-const removeFromNetwork = () => {
-  for (let i = selectorsFromNetwork.length; i--; ) {
-    const selector = selectorsFromNetwork[i];
-    const element = search(selector);
-
-    if (element) {
-      const tagName = element.tagName.toUpperCase();
-
-      if (!["BODY", "HTML"].includes(tagName)) {
-        element.remove();
-        dispatch({
-          hostname: document.location.hostname,
-          state: { matches: [selector] },
-          type: "UPDATE_CACHE",
 });
-      }
-    }
-  }
-};
 
 /**
- * @function runTasks
+ * @description Setups elements selectors
- * @description Starts running tasks
+ * @type {Promise<boolean>}
  */
 
-const runTasks = () => {
+const setupSelectors = new Promise((resolve) => {
-  if (attempts <= 20) {
+  dispatch({ type: "GET_SELECTORS" }, null, ({ selectors }) => {
-    fix();
+    selectorsFromNetwork = chunkerize(selectors);
-    removeFromCache();
+    resolve(true);
-    if (attempts <= 5) removeFromNetwork();
+  });
-    if (document.readyState === "complete") attempts += 1;
+});
-  }
-
-  if (attempts > 20) {
-    clearInterval(intervalId);
-  }
-};
-
-/**
- * @description Setup extension context
- */
 
 dispatch(
   { hostname: document.location.hostname, type: "GET_CACHE" },
   null,
-  ({ enabled, matches }) => {
+  async ({ enabled, matches }) => {
     dispatch({ type: "ENABLE_POPUP" });
 
     if (enabled) {
       selectorsFromCache = matches;
       dispatch({ type: "ENABLE_ICON" });
-      dispatch({ type: "GET_LIST" }, null, ({ selectors }) => {
+      await Promise.all([setupClasses, setupSelectors]);
-        selectorsFromNetwork = selectors;
+      setInterval(runTasks, 500);
-        intervalId = setInterval(runTasks, 500);
-      });
     }
   }
 );