Author: John Au-Yeung

To install and run Mocha, the Node.js testing module, we install the mocha package globally.

To install it, we run

npm install --global mocha

to install mocha globally.

We can also install it in the project folder as a dev dependency with

npm install --save-dev mocha

Then in package.json, we add

{
  //...
  "scripts": {
    "test": "mocha"
  }
  //...
}

to add the test script to run mocha installed in the node_modules folder.

To fix ‘ng: command not found’ error with Angular, we install the @angular/cli package.

To install it, we run

npm i -g @angular/cli

To fix Npm Please try using this command again as root/administrator error with JavaScript, we run npm as an administrator.

To do this, we:

1. Click Start, click All Programs, and then click Accessories.
2. Right-click Command prompt, and then click Run as administrator.

Then we run the npm command in the administrator command prompt.

To install a specific version of Node on Ubuntu, we use the n module.

For instance, we run

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

to clear the npm cache with

sudo npm cache clean -f

Then we install the n module globally with

sudo npm install -g n

We run n with

sudo n stable

Then we install Node 16.15.1 with

sudo n 16.15.1

To fix Webpack 4 "size exceeds the recommended limit (244 KiB)" error with JavaScript, we set devtool to false.

For instance, in webpack.config.js, we write

const mode = process.env.NODE_ENV || "development";
module.exports = {
  //...
  devtool: mode === "development" ? "inline-source-map" : false,
  mode,
  //...
};

to set devtool to false is mode isn’t 'development'.