Web developer specializing in React, Vue, and front end development.
Sometimes, we want to restart Node upon changing a file.
In this article, we’ll look at how to restart Node upon changing a file.
To restart Node upon changing a file, we can use the supervisor package.
We install it by running
npm install supervisor -g
Then we can watch for file changes in the Node project with entry point app.js by running
supervisor app.js
To restart Node upon changing a file, we can use the supervisor package.
Sometimes, we want to move files in Node.js.
In this article, we’ll look at how to move files in Node.js.
To move files in Node.js, we can use the fs.rename method.
For instance, we write
const fs = require('fs')
const oldPath = 'old/path/file.txt'
const newPath = 'new/path/file.txt'
fs.rename(oldPath, newPath, (err) => {
if (err) {
throw err
}
console.log('successfully moved')
})
to call rename with the oldPath of the file, newPath of the file, and a callback that runs when the moving is done.
If there’s an error, err will be set.
To move files in Node.js, we can use the fs.rename method.
Sometimes, we want to read a text file into an array with each line an item in the array.
In this article, we’ll look at how to read a text file into an array with each line an item in the array.
To read a text file into an array with each line an item in the array, we can use the readFileSync or readFile method.
For instance, we write
const fs = require('fs');
const array = fs.readFileSync('file.txt').toString().split("\n");
for (const a of array) {
console.log(a);
}
to call fs.readFileSync to read 'file.txt' synchronously.
Then we call toString to return the read file as a string.
And then we split the string into an array with each line as an item with split.
Then we loop through each array entry with the for-of loop.
We call readFile to read the file asynchronously.
To use it, we write
const fs = require('fs');
fs.readFile('file.txt', (err, data) => {
if (err) {
throw err;
}
const array = data.toString().split("\n");
for (const a of array) {
console.log(a);
}
});
to call readFile to read 'file.txt'.
The callback is run when the file is read.
And we convert the file to a string, split the lines, and loop through them the same way.
To read a text file into an array with each line an item in the array, we can use the readFileSync or readFile method.
Sometimes, we want to create a proxy with Express.js.
In this article, we’ll look at how to create a proxy with Express.js.
To create a proxy with Express.js, we can use the express-http-proxy package.
To install it, we run
npm i express-http-proxy
Then we write
const url = require('url');
const proxy = require('express-http-proxy');
const apiProxy = proxy('example.com:3000/test', {
proxyReqPathResolver: req => url.parse(req.baseUrl).path
});
to call proxy with the URL we want to proxy and an object that has the proxyReqPathResolver property set to a function to map the URL we’re proxy to a URL in our app.
url.parse parses the URL and we get the URL path with path.
To create a proxy with Express.js, we can use the express-http-proxy package.
Sometimes, we want to return the current timestamp with Moment.js.
In this article, we’ll look at how to return the current timestamp with Moment.js.
To return the current timestamp with Moment.js, we can use the unix method.
For instance, we write
const currentDate = moment().unix();
to return the current UNIX timestamp.
To return the current timestamp with Moment.js, we can use the unix method.