text: // @remove-on-eject-begin
  /**
   * Copyright (c) 2015-present, Facebook, Inc.
   *
   * This source code is licensed under the MIT license found in the
   * LICENSE file in the root directory of this source tree.
   */
  // @remove-on-eject-end
  "use strict";
  
  // Do this as the first thing so that any code reading it knows the right env.
  process.env.BABEL_ENV = "production";
  process.env.NODE_ENV = "production";
  
  // Makes the script crash on unhandled rejections instead of silently
  // ignoring them. In the future, promise rejections that are not handled will
  // terminate the Node.js process with a non-zero exit code.
  process.on("unhandledRejection", (err) => {
    throw err;
  });
  
  // Ensure environment variables are read.
  require("../config/env");
  
  const path = require("path");
  const chalk = require("react-dev-utils/chalk");
  const fs = require("fs-extra");
  const bfj = require("bfj");
  const webpack = require("webpack");
  const configFactory = require("../config/webpack.config");
  const paths = require("../config/paths");
  const checkRequiredFiles = require("react-dev-utils/checkRequiredFiles");
  const formatWebpackMessages = require("react-dev-utils/formatWebpackMessages");
  const printHostingInstructions = require("react-dev-utils/printHostingInstructions");
  const FileSizeReporter = require("react-dev-utils/FileSizeReporter");
  const printBuildError = require("react-dev-utils/printBuildError");
  
  const measureFileSizesBeforeBuild =
    FileSizeReporter.measureFileSizesBeforeBuild;
  const printFileSizesAfterBuild = FileSizeReporter.printFileSizesAfterBuild;
  const useYarn = fs.existsSync(paths.yarnLockFile);
  
  // These sizes are pretty large. We'll warn for bundles exceeding them.
  const WARN_AFTER_BUNDLE_GZIP_SIZE = 512 * 1024;
  const WARN_AFTER_CHUNK_GZIP_SIZE = 1024 * 1024;
  
  const isInteractive = process.stdout.isTTY;
  
  // Warn and crash if required files are missing
  if (!checkRequiredFiles([paths.appHtml, paths.appIndexJs])) {
    process.exit(1);
  }
  
  const argv = process.argv.slice(2);
  const writeStatsJson = argv.indexOf("--stats") !== -1;
  
  // Generate configuration
  const config = configFactory("production");
  
  // We require that you explicitly set browsers and do not fall back to
  // browserslist defaults.
  const { checkBrowsers } = require("react-dev-utils/browsersHelper");
  checkBrowsers(paths.appPath, isInteractive)
    .then(() => {
      // First, read the current file sizes in build directory.
      // This lets us display how much they changed later.
      return measureFileSizesBeforeBuild(paths.appBuild);
    })
    .then((previousFileSizes) => {
      // Remove all content but keep the directory so that
      // if you're in it, you don't end up in Trash
      fs.emptyDirSync(paths.appBuild);
      // Merge with the public folder
      copyPublicFolder();
      // Start the webpack build
      return build(previousFileSizes);
    })
    .then(
      ({ stats, previousFileSizes, warnings }) => {
        if (warnings.length) {
          console.log(chalk.yellow("Compiled with warnings.\n"));
          console.log(warnings.join("\n\n"));
          console.log(
            "\nSearch for the " +
              chalk.underline(chalk.yellow("keywords")) +
              " to learn more about each warning."
          );
          console.log(
            "To ignore, add " +
              chalk.cyan("// eslint-disable-next-line") +
              " to the line before.\n"
          );
        } else {
          console.log(chalk.green("Compiled successfully.\n"));
        }
  
        console.log("File sizes after gzip:\n");
        printFileSizesAfterBuild(
          stats,
          previousFileSizes,
          paths.appBuild,
          WARN_AFTER_BUNDLE_GZIP_SIZE,
          WARN_AFTER_CHUNK_GZIP_SIZE
        );
        console.log();
  
        const appPackage = require(paths.appPackageJson);
        const publicUrl = paths.publicUrlOrPath;
        const publicPath = config.output.publicPath;
        const buildFolder = path.relative(process.cwd(), paths.appBuild);
        printHostingInstructions(
          appPackage,
          publicUrl,
          publicPath,
          buildFolder,
          useYarn
        );
      },
      (err) => {
        const tscCompileOnError = process.env.TSC_COMPILE_ON_ERROR === "true";
        if (tscCompileOnError) {
          console.log(
            chalk.yellow(
              "Compiled with the following type errors (you may want to check these before deploying your app):\n"
            )
          );
          printBuildError(err);
        } else {
          console.log(chalk.red("Failed to compile.\n"));
          printBuildError(err);
          process.exit(1);
        }
      }
    )
    .catch((err) => {
      if (err && err.message) {
        console.log(err.message);
      }
      process.exit(1);
    });
  
  // Create the production build and print the deployment instructions.
  function build(previousFileSizes) {
    console.log("Creating an optimized production build...");
  
    const compiler = webpack(config);
    return new Promise((resolve, reject) => {
      compiler.run((err, stats) => {
        let messages;
        if (err) {
          if (!err.message) {
            return reject(err);
          }
  
          let errMessage = err.message;
  
          // Add additional information for postcss errors
          if (Object.prototype.hasOwnProperty.call(err, "postcssNode")) {
            errMessage +=
              "\nCompileError: Begins at CSS selector " +
              err["postcssNode"].selector;
          }
  
          messages = formatWebpackMessages({
            errors: [errMessage],
            warnings: [],
          });
        } else {
          messages = formatWebpackMessages(
            stats.toJson({ all: false, warnings: true, errors: true })
          );
        }
        if (messages.errors.length) {
          // Only keep the first error. Others are often indicative
          // of the same problem, but confuse the reader with noise.
          if (messages.errors.length > 1) {
            messages.errors.length = 1;
          }
          return reject(new Error(messages.errors.join("\n\n")));
        }
        if (
          process.env.CI &&
          (typeof process.env.CI !== "string" ||
            process.env.CI.toLowerCase() !== "false") &&
          messages.warnings.length
        ) {
          // Ignore sourcemap warnings in CI builds. See #8227 for more info.
          const filteredWarnings = messages.warnings.filter(
            (w) => !/Failed to parse source map/.test(w)
          );
          if (filteredWarnings.length) {
            console.log(
              chalk.yellow(
                "\nTreating warnings as errors because process.env.CI = true.\n" +
                  "Most CI servers set it automatically.\n"
              )
            );
            return reject(new Error(filteredWarnings.join("\n\n")));
          }
        }
  
        const resolveArgs = {
          stats,
          previousFileSizes,
          warnings: messages.warnings,
        };
  
        if (writeStatsJson) {
          return bfj
            .write(paths.appBuild + "/bundle-stats.json", stats.toJson())
            .then(() => resolve(resolveArgs))
            .catch((error) => reject(new Error(error)));
        }
  
        return resolve(resolveArgs);
      });
    });
  }
  
  function copyPublicFolder() {
    fs.copySync(paths.appPublic, paths.appBuild, {
      dereference: true,
      filter: (file) => file !== paths.appHtml,
    });
  }
  