Category: JavaScript

To make Node pm2 log to console, we call connect.

For instance, we write

const pm2 = require("pm2");

pm2.connect((err) => {
  if (err) {
    console.error(err);
    process.exit(2);
  }
  pm2.start(
    [
      {
        script: "server.js",
        output: "/dev/stdout",
        error: "/dev/stderr",
      },
    ],
    (err, proc) => {
      if (err) {
        throw err;
      }
    }
  );
});

to call connect with a callback that calls start with some options.

We set output to the location to '/dev/stdout' to log to the console.

And we log errors to '/dev/stderr' by setting error to "/dev/stderr".

To use Node Mongoose Find with multiple conditions, we put all the conditions in one object.

For instance, we write

User.find(
  { $or: [{ region: "NA" }, { sector: "Some Sector" }] },
  (err, user) => {
    if (err) {
      res.send(err);
    }
    console.log(user);
    res.json(user);
  }
);

to call find with an object with $or set to an array of conditions we’re looking for.

And we get the result from user in the callback.

To fix Error: Failed to launch the browser process with Node Puppeteer, we call launch with the browser path.

To fix this, we run

sudo apt-get install chromium-browser

to install the Chromium browser.

Then we write

const browser = await puppeteer.launch({
  executablePath: "/usr/bin/chromium-browser",
});

to call launch with an object with the executablePath set to the Chromium browser path to start it.

To fix npm install hangs on loadIdealTree:loadAllDepsIntoIdealTree: sill install loadIdealTree, we remove the package.json file.

To fix this, we remove the package.json file and then run

npm install

to install all packages again.

To broadcast messages on a namespace with Node socket.io, we call broadcast.emit.

For instance, we write

chat.on("connection", (socket) => {
  socket.on("message", (msg) => {
    socket.emit(msg);
    socket.broadcast.emit(msg);
  });
});

to call broadcast.emit to broadcast the msg string to all clients.