How to serve yarn build file with npm serve command?

Question

Basically, my task is to compile a js file and serve it at http://localhost:5000/final.js

I have the following script.

Current issues

The console.log seems printing out of order.
Able to switch dir and run yarn build, but it seems not able to serve file

Here is the source code:

#!/usr/bin/env node

const frontendDir =
  "/my/frontend";
const jsDir =
  "/my/frontend/build/static/js";

// util
const util = require("util");
// exec
const exec = util.promisify(require("child_process").exec);

// async func
async function runcmd(cmd) {
  try {
    const { stdout, stderr } = await exec(cmd);
    // need output
    console.log("stdout:", stdout);
    // need error
    console.log("stderr:", stderr);
  } catch (err) {
    console.error(err);
  }
}

try {
  // go to front end dir
  process.chdir(frontendDir);
  console.log("Switch to dir: " + process.cwd());

  // yarn build
  runcmd("yarn build");

  // go to file dir
  process.chdir(jsDir);
  console.log("Switch to dir: " + process.cwd());

  // find that js file and copy it, rename it
  runcmd("cp main.*.js final.js");

  // serve at /my/frontend/build/static/js with url http://localhost:5000/final.js
  runcmd("serve .");
} catch (err) {
  console.log("chdir: " + err);
}

Here is the output from the script above

Switch to dir: /my/frontend
Switch to dir: /my/frontend/build/static/js
stdout: 
stderr: 
stdout: yarn run v1.21.1
$ react-app-rewired build && cpr ./build/ ../build/frontend/ -o
Creating an optimized production build...
Compiled successfully.

File sizes after gzip:

  210.3 KB  build/static/js/main.c1e6b0e9.js

The project was built assuming it is hosted at ./.
You can control this with the homepage field in your package.json.

The build folder is ready to be deployed.

Find out more about deployment here:



Done in 13.91s.

stderr:

score 0 · Answer 1 · answered Jan 22 '20 at 23:06

// https://stackoverflow.com/questions/41037042/nodejs-wait-for-exec-in-function
const exec = require("child_process").exec;

function os_func() {
  this.execCommand = function(cmd) {
    return new Promise((resolve, reject) => {
      exec(cmd, (error, stdout, stderr) => {
        if (error) {
          reject(error);
          return;
        }
        resolve(stdout);
      });
    });
  };
}
const os = new os_func();

process.chdir(frontendDir);
os.execCommand("yarn buildlocal")
  .then(() => {
    console.log("@ done yarn build");
    process.chdir(jsDir);
    os.execCommand("cp main.*.js docman.js").then(() => {
      console.log("@ done copy and serve at port 5000");
      os.execCommand("serve -l 5000 .").then(() => {});
    });
  })
  .catch(err => {
    console.log("os >>>", err);
  });

How to serve yarn build file with npm serve command?

1 Answers1