assets/scripts/build.js

   1 import dateFormat from "dateformat";
   2 import crypto from "crypto";
   3 import { promises as fs } from "fs";
   4 import path from "path";
   5 import { fileURLToPath } from "url";
   6
   7 // Filters structure
   8 import filters from "../../filters.json" with { type: "json" };
   9
  10 const NULL_IP = "0.0.0.0";
  11
  12 // For header example, see https://easylist-downloads.adblockplus.org/easylist.txt
  13 const currentDate = new Date();
  14 const version = dateFormat(currentDate, "yyyymmddHHMM", true);
  15 const lastModified = dateFormat(currentDate, "dd mmm yyyy HH:MM Z", true);
  16
  17 const __filename = fileURLToPath(import.meta.url);
  18 const __dirname = path.dirname(__filename);
  19
  20 const calculateChecksum = (content) => {
  21   const rest = content.replace(/! Checksum: #CHECKSUM#\n/, "");
  22   return crypto
  23     .createHash("md5")
  24     .update(rest)
  25     .digest("base64")
  26     .replace("==", "");
  27 };
  28
  29 const withFinalNL = (content) => content.toString().trim() + "\n";
  30
  31 const buildFilters = async () => {
  32   console.log("Build filters...");
  33   for (const filter of filters) {
  34     if (!filter.hasOwnProperty("sections")) continue;
  35     console.log(` * Building list: ${filter.output}`);
  36     try {
  37       // Collect header
  38       let headerContent = "";
  39       if (filter.hasOwnProperty("header")) {
  40         headerContent += withFinalNL(
  41           await fs.readFile(
  42             path.join(__dirname, `../../sections/headers/${filter.header}`)
  43           )
  44         );
  45         console.log(`   - Header: ${filter.header} added`);
  46       }
  47       // Collect sections
  48       console.log(`   - Sections:`);
  49       let content = "";
  50       for (const section of filter.sections) {
  51         content += withFinalNL(
  52           await fs.readFile(path.join(__dirname, `../../sections/${section}`))
  53         );
  54         console.log(`      - ${section} added`);
  55       }
  56       // Handle DNS / hosts filters
  57       if (filter.dns || filter.hosts) {
  58         // TODO: Switch to AGTree and extract domain from pattern with tldts
  59         const regex = /^\|\|([a-z0-9]+([-.][a-z0-9]+)*\.[a-z]{2,})($|\^$)/gm;
  60         const matches = content.matchAll(regex);
  61         const domains = Array.from(matches, ([_, domain]) => domain);
  62         content = (
  63           filter.hosts
  64             ? domains.map((domain) => `${NULL_IP} ${domain}`)
  65             : domains
  66         ).join("\n");
  67       }
  68       // Remove empty lines
  69       const strippedFilters =
  70         content
  71           .split(/\r?\n/)
  72           .filter((line) => line.replace("!", "").trim().length > 0)
  73           .join("\n") +
  74         "\n";
  75       // Header attributes
  76       if (headerContent.length) {
  77         // Versions
  78         headerContent = headerContent.replace(/#VERSION#/, version);
  79         headerContent = headerContent.replace(/#LAST_MODIFIED#/, lastModified);
  80         headerContent = headerContent.replace(/#TITLE#/, filter.title || "hufilter");
  81         // Checksum
  82         const checksum = await calculateChecksum(headerContent + strippedFilters);
  83         headerContent = headerContent.replace(/#CHECKSUM#/, checksum);
  84       }
  85       const fileContent = headerContent + strippedFilters;
  86       // Write output
  87       await fs.writeFile(
  88         path.join(__dirname, `../../dist/${filter.output}`),
  89         fileContent
  90       );
  91     } catch (err) {
  92       console.log(`   - FAILED: ${err.message}`);
  93     }
  94   }
  95 };
  96
  97 (async () => {
  98   // Create dist folder if not exists
  99   try {
 100     await fs.mkdir(path.join(__dirname, "../../dist"));
 101   } catch (err) {}
 102
 103   await buildFilters();
 104 })();