Category: JavaScript

To fix npm – "Can’t find Python executable "python", you can set the PYTHON env variable." error with JavaScript, we install the window-build-tools package.

To fix this, we run

npm install -g windows-build-tools

to install the window-build-tools package globally which includes Python.

To fix the /usr/bin/env: node: No such file or directory error with Node forever, we clear the npm cache.

We run

sudo npm cache clean -f
sudo npm install -g n
sudo n stable

to force clear the NPM cache with

sudo npm cache clean -f

Then we install the latest version of n with

sudo npm install -g n

We run the latest stablke version with

n stable

To protect the password field in Mongoose/MongoDB so it won’t return in a query when populating collections with JavaScript, we set the select option to false.

For instance, we write

const userSchema = new Schema({
  name: { type: String, required: false, minlength: 5 },
  email: { type: String, required: true, minlength: 5 },
  phone: String,
  password: { type: String, select: false },
});

to create a schema with the password field having the select option set to false.

Then the field’s value won’t be returned when we query the userSchema.

To find the size of the file in Node.js, we use the statSync method.

For instance, we write

const fs = require("fs");

const stats = fs.statSync("myfile.txt");
const fileSizeInBytes = stats.size;
const fileSizeInMegabytes = fileSizeInBytes / (1024 * 1024);

to call statSync to get the stats for the myfile.txt file.

We get the file size in bytes with stats.size.

Then we convert it to megabytes by dividing it by 1024 * 1024.

To select where in array of _id with MongoDB and JavaScript, we call the find method.

For instance, we write

db.collection.find({ _id: { $in: [ObjectId("1"), ObjectId("2")] } });

to call find with an object with the _id property set to an array with the object IDs to look for in the collection.