unpkg/scripts/build.js

"use strict"

// Do this as the first thing so that any code reading it knows the right env.
process.env.NODE_ENV = "production"

// Load environment variables from .env file. Suppress warnings using silent
// if this file is missing. dotenv will never modify any environment variables
// that have already been set.
// https://github.com/motdotla/dotenv
require("dotenv").config({ silent: true })

var chalk = require("chalk")
var fs = require("fs-extra")
var path = require("path")
var url = require("url")
var webpack = require("webpack")
var config = require("../config/webpack.config.prod")
var paths = require("../config/paths")
var checkRequiredFiles = require("react-dev-utils/checkRequiredFiles")
var FileSizeReporter = require("react-dev-utils/FileSizeReporter")
var measureFileSizesBeforeBuild = FileSizeReporter.measureFileSizesBeforeBuild
var printFileSizesAfterBuild = FileSizeReporter.printFileSizesAfterBuild

var useYarn = fs.existsSync(paths.yarnLockFile)

// Warn and crash if required files are missing
if (!checkRequiredFiles([paths.appHtml, paths.appIndexJs])) {
  process.exit(1)
}

// First, read the current file sizes in build directory.
// This lets us display how much they changed later.
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)

  // Start the webpack build
  build(previousFileSizes)

  // Merge with the public folder
  copyPublicFolder()
})

// Print out errors
function printErrors(summary, errors) {
  console.log(chalk.red(summary))
  console.log()
  errors.forEach(err => {
    console.log(err.message || err)
    console.log()
  })
}

// Create the production build and print the deployment instructions.
function build(previousFileSizes) {
  console.log("Creating an optimized production build...")
  webpack(config).run((err, stats) => {
    if (err) {
      printErrors("Failed to compile.", [err])
      process.exit(1)
    }

    if (stats.compilation.errors.length) {
      printErrors("Failed to compile.", stats.compilation.errors)
      process.exit(1)
    }

    if (process.env.CI && stats.compilation.warnings.length) {
      printErrors(
        "Failed to compile. When process.env.CI = true, warnings are treated as failures. Most CI servers set this automatically.",
        stats.compilation.warnings
      )
      process.exit(1)
    }

    console.log(chalk.green("Compiled successfully."))
    console.log()

    console.log("File sizes after gzip:")
    console.log()
    printFileSizesAfterBuild(stats, previousFileSizes)
    console.log()

    var appPackage = require(paths.appPackageJson)
    var publicUrl = paths.publicUrl
    var publicPath = config.output.publicPath
    var publicPathname = url.parse(publicPath).pathname
    if (publicUrl && publicUrl.indexOf(".github.io/") !== -1) {
      // "homepage": "http://user.github.io/project"
      console.log(
        "The project was built assuming it is hosted at " + chalk.green(publicPathname) + "."
      )
      console.log(
        "You can control this with the " +
          chalk.green("homepage") +
          " field in your " +
          chalk.cyan("package.json") +
          "."
      )
      console.log()
      console.log("The " + chalk.cyan("build") + " folder is ready to be deployed.")
      console.log("To publish it at " + chalk.green(publicUrl) + ", run:")
      // If script deploy has been added to package.json, skip the instructions
      if (typeof appPackage.scripts.deploy === "undefined") {
        console.log()
        if (useYarn) {
          console.log("  " + chalk.cyan("yarn") + " add --dev gh-pages")
        } else {
          console.log("  " + chalk.cyan("npm") + " install --save-dev gh-pages")
        }
        console.log()
        console.log("Add the following script in your " + chalk.cyan("package.json") + ".")
        console.log()
        console.log("    " + chalk.dim("// ..."))
        console.log("    " + chalk.yellow('"scripts"') + ": {")
        console.log("      " + chalk.dim("// ..."))
        console.log(
          "      " + chalk.yellow('"predeploy"') + ": " + chalk.yellow('"npm run build",')
        )
        console.log(
          "      " + chalk.yellow('"deploy"') + ": " + chalk.yellow('"gh-pages -d build"')
        )
        console.log("    }")
        console.log()
        console.log("Then run:")
      }
      console.log()
      console.log("  " + chalk.cyan(useYarn ? "yarn" : "npm") + " run deploy")
      console.log()
    } else if (publicPath !== "/") {
      // "homepage": "http://mywebsite.com/project"
      console.log("The project was built assuming it is hosted at " + chalk.green(publicPath) + ".")
      console.log(
        "You can control this with the " +
          chalk.green("homepage") +
          " field in your " +
          chalk.cyan("package.json") +
          "."
      )
      console.log()
      console.log("The " + chalk.cyan("build") + " folder is ready to be deployed.")
      console.log()
    } else {
      if (publicUrl) {
        // "homepage": "http://mywebsite.com"
        console.log(
          "The project was built assuming it is hosted at " + chalk.green(publicUrl) + "."
        )
        console.log(
          "You can control this with the " +
            chalk.green("homepage") +
            " field in your " +
            chalk.cyan("package.json") +
            "."
        )
        console.log()
      } else {
        // no homepage
        console.log("The project was built assuming it is hosted at the server root.")
        console.log(
          "To override this, specify the " +
            chalk.green("homepage") +
            " in your " +
            chalk.cyan("package.json") +
            "."
        )
        console.log("For example, add this to build it for GitHub Pages:")
        console.log()
        console.log(
          "  " +
            chalk.green('"homepage"') +
            chalk.cyan(": ") +
            chalk.green('"http://myname.github.io/myapp"') +
            chalk.cyan(",")
        )
        console.log()
      }
      var build = path.relative(process.cwd(), paths.appBuild)
      console.log("The " + chalk.cyan(build) + " folder is ready to be deployed.")
      console.log("You may serve it with a static server:")
      console.log()
      if (useYarn) {
        console.log(`  ${chalk.cyan("yarn")} global add serve`)
      } else {
        console.log(`  ${chalk.cyan("npm")} install -g serve`)
      }
      console.log(`  ${chalk.cyan("serve")} -s build`)
      console.log()
    }
  })
}

function copyPublicFolder() {
  fs.copySync(paths.appPublic, paths.appBuild, {
    dereference: true,
    filter: file => file !== paths.appHtml
  })
}