handy-service/scripts/serve.js

> service for handy-cli

process.env.BABEL_ENV = "development";
process.env.NODE_ENV = "development";

process.on("unhandledRejection", err => {
  throw err;
});

// Ensure environment variables are read.
require("../config/env");

const fs = require("fs");
const { fork } = require("child_process");
const path = require("path");
const chalk = require("chalk");
const webpack = require("webpack");
const WebpackDevServer = require("webpack-dev-server");
const clearConsole = require("react-dev-utils/clearConsole");
const {
  choosePort,
  createCompiler,
  prepareProxy,
  prepareUrls
} = require("react-dev-utils/WebpackDevServerUtils");
const openBrowser = require("react-dev-utils/openBrowser");
const paths = require("../config/paths");
const config = require("../config/webpack.config.dev");
const createDevServerConfig = require("../config/webpackDevServer.config");

const useYarn = fs.existsSync(paths.yarnLockFile);
const isInteractive = process.stdout.isTTY;

const DEFAULT_PORT = parseInt(process.env.PORT, 10) || 3000;
const HOST = process.env.HOST || "0.0.0.0";
if (process.env.HOST) {
  console.log(
    chalk.cyan(
      `Attempting to bind to HOST environment variable: ${chalk.yellow(
        chalk.bold(process.env.HOST)
      )}`
    )
  );
  console.log("If this was unintentional, check that you haven't mistakenly set it in your shell.");
  console.log(`Learn more here: ${chalk.yellow("http://bit.ly/2mwWSwH")}`);
  console.log();
}

// We attempt to use the default port but if it is busy, we offer the user to
// run on a different port. `choosePort()` Promise resolves to the next free port.

function startServer() {
  choosePort(HOST, DEFAULT_PORT)
    .then(port => {
      if (port == null) {
        // We have not found a port.
        return;
      }
      const protocol = process.env.HTTPS === "true" ? "https" : "http";
      const appName = require(paths.appPackageJson).name;
      const urls = prepareUrls(protocol, HOST, port);
      // Create a webpack compiler that is configured with custom messages.
      const compiler = createCompiler(webpack, config, appName, urls, useYarn);
      // Load proxy config
      const proxySetting = require(paths.appPackageJson).proxy;
      const proxyConfig = prepareProxy(proxySetting, paths.appPublic);
      // Serve webpack assets generated by the compiler over a web sever.
      const serverConfig = createDevServerConfig(proxyConfig, urls.lanUrlForConfig);
      const devServer = new WebpackDevServer(compiler, serverConfig);
      // Launch WebpackDevServer.
      devServer.listen(port, HOST, err => {
        if (err) {
          return console.log(err);
        }
        if (isInteractive) {
          clearConsole();
        }
        console.log(chalk.cyan("Starting the development server...\n"));
        openBrowser(urls.localUrlForBrowser);
      });

      ["SIGINT", "SIGTERM"].forEach(sig => {
        process.on(sig, () => {
          devServer.close();
          process.exit();
        });
      });
    })
    .catch(err => {
      if (err && err.message) {
        console.log(err.message);
      }
      process.exit(1);
    });
}

function watchModifyVars() {
  const modifyVarsPath = path.join(process.cwd(), "modifyVars.json");
  if (fs.existsSync(modifyVarsPath)) {
    fs.watchFile(modifyVarsPath, () => {
      console.log(chalk.green("modifyVars.json changed,restart server..."));
      process.send("RESTART");
    });
  }
}

if (process.channel) {
  // in child process
  startServer();
  watchModifyVars();
} else {
  const startChild = () => {
    const childProcess = fork(path.join(__dirname, "./serve.js"));
    childProcess.on("message", SIG => {
      if (SIG === "RESTART") {
        childProcess.kill("SIGTERM");
        startChild();
      }
    });
  };
  startChild();
}