webpack-bundle-analyzer/lib/bin/analyzer.js

Webpack plugin and CLI utility that represents bundle content as convenient interactive zoomable treemap

#! /usr/bin/env node
"use strict";

const {
  dirname,
  resolve
} = require("node:path");
const {
  program: commanderProgram
} = require("commander");
const {
  magenta
} = require("picocolors");
const Logger = require("../Logger");
const analyzer = require("../analyzer");
const {
  isZstdSupported
} = require("../sizeUtils");
const utils = require("../utils");
const viewer = require("../viewer");
const SIZES = new Set(["stat", "parsed", "gzip"]);
const COMPRESSION_ALGORITHMS = new Set(isZstdSupported ? ["gzip", "brotli", "zstd"] : ["gzip", "brotli"]);

/**
 * @param {string} str string
 * @returns {string} break with string
 */
function br(str) {
  return `\n${" ".repeat(32)}${str}`;
}

/**
 * @template T
 * @returns {(val: T) => T[]} array
 */
function array() {
  /** @type {T[]} */
  const arr = [];
  return val => {
    arr.push(val);
    return arr;
  };
}
const program = commanderProgram.version(require("../../package.json").version).argument("<bundleStatsFile>", "Path to Webpack Stats JSON file.").argument("[bundleDir]", "Directory containing all generated bundles. You should provided it if you want analyzer to show you the real parsed module sizes. By default a directory of stats file is used.").option("-m, --mode <mode>", `Analyzer mode. Should be \`server\`,\`static\` or \`json\`.${br("In `server` mode analyzer will start HTTP server to show bundle report.")}${br("In `static` mode single HTML file with bundle report will be generated.")}${br("In `json` mode single JSON file with bundle report will be generated.")}`, "server").option(
// Had to make `host` parameter optional in order to let `-h` flag output help message
// Fixes https://github.com/webpack/webpack-bundle-analyzer/issues/239
"-h, --host [host]", "Host that will be used in `server` mode to start HTTP server.", "127.0.0.1").option("-p, --port <n>", "Port that will be used in `server` mode to start HTTP server.", "8888").option("-r, --report <file>", "Path to bundle report file that will be generated in `static` mode.").option("-t, --title <title>", "String to use in title element of html report.").option("-s, --default-sizes <type>", `Module sizes to show in treemap by default.${br(`Possible values: ${[...SIZES].join(", ")}`)}`, "parsed").option("--compression-algorithm <type>", `Compression algorithm that will be used to calculate the compressed module sizes.${br(`Possible values: ${[...COMPRESSION_ALGORITHMS].join(", ")}`)}`, "gzip").option("-O, --no-open", "Don't open report in default browser automatically.").option("-e, --exclude <regexp>", `Assets that should be excluded from the report.${br("Can be specified multiple times.")}`, array()).option("-l, --log-level <level>", `Log level.${br(`Possible values: ${[...Logger.levels].join(", ")}`)}`, Logger.defaultLevel).parse();
let [bundleStatsFile, bundleDir] = program.args;
let {
  mode,
  host,
  port,
  report: reportFilename,
  title: reportTitle,
  defaultSizes,
  compressionAlgorithm,
  logLevel,
  open: openBrowser,
  exclude: excludeAssets
} = program.opts();
const logger = new Logger(logLevel);
if (typeof reportTitle === "undefined") {
  reportTitle = utils.defaultTitle;
}

/**
 * @param {string} error error message
 */
function showHelp(error) {
  if (error) console.log(`\n  ${magenta(error)}\n`);
  program.outputHelp();
  process.exit(1);
}
if (!bundleStatsFile) {
  showHelp("Provide path to Webpack Stats file as first argument");
}
if (mode !== "server" && mode !== "static" && mode !== "json") {
  showHelp("Invalid mode. Should be either `server`, `static` or `json`.");
}
if (mode === "server") {
  if (!host) showHelp("Invalid host name");
  port = port === "auto" ? 0 : Number(port);
  if (Number.isNaN(port)) {
    showHelp("Invalid port. Should be a number or `auto`");
  }
}
if (!COMPRESSION_ALGORITHMS.has(compressionAlgorithm)) {
  showHelp(`Invalid compression algorithm option. Possible values are: ${[...COMPRESSION_ALGORITHMS].join(", ")}`);
}
if (!SIZES.has(defaultSizes)) {
  showHelp(`Invalid default sizes option. Possible values are: ${[...SIZES].join(", ")}`);
}
bundleStatsFile = resolve(bundleStatsFile);
if (!bundleDir) bundleDir = dirname(bundleStatsFile);

/**
 * @param {string} bundleStatsFile bundle stats file
 * @returns {Promise<void>}
 */
async function parseAndAnalyse(bundleStatsFile) {
  try {
    const bundleStats = await analyzer.readStatsFromFile(bundleStatsFile);
    if (mode === "server") {
      viewer.startServer(bundleStats, {
        openBrowser,
        port,
        host,
        defaultSizes,
        compressionAlgorithm,
        reportTitle,
        bundleDir,
        excludeAssets,
        logger: new Logger(logLevel),
        analyzerUrl: utils.defaultAnalyzerUrl
      });
    } else if (mode === "static") {
      viewer.generateReport(bundleStats, {
        openBrowser,
        reportFilename: resolve(reportFilename || "report.html"),
        reportTitle,
        defaultSizes,
        compressionAlgorithm,
        bundleDir,
        excludeAssets,
        logger: new Logger(logLevel)
      });
    } else if (mode === "json") {
      viewer.generateJSONReport(bundleStats, {
        reportFilename: resolve(reportFilename || "report.json"),
        compressionAlgorithm,
        bundleDir,
        excludeAssets,
        logger: new Logger(logLevel)
      });
    }
  } catch (err) {
    logger.error(`Couldn't read webpack bundle stats from "${bundleStatsFile}":\n${err}`);
    logger.debug(/** @type {Error} */err.stack);
    process.exit(1);
  }
}
parseAndAnalyse(bundleStatsFile);