This article assumes you:
- Have basic familiarly with the command line (creating and changing directories, running commands, etc)
- Have Visual Studio Code installed
- Have Node.js installed
In order to install and use ESLint, we’re going to need to create a folder to hold our code. Additional, we’ll be creating a special file called
package.json that will describe our project and what it needs to work.
Create a folder somewhere and open it in Visual Studio Code by going to the menu bar and selecting File → Open Folder…. Choose your folder and hit OK.
Open the Terminal in Visual Studio Code by going to the menu bar and selecting Terminal → New Terminal. In the newly opened terminal window, initialize a new Node project:
It’ll ask you a series of questions, but you can just hit enter to accept the defaults.
You should now have a
package.json file in your file tree.
Add the ESLint package to your project:
npm install eslint
Then create an ESLint config file:
Again, you’ll get a series of questions. If you’re not sure how to answer them, you can use these answers:
How would you like to use ESLint?
Go to the menu bar and select View → Extensions. In the search bar in the Extensions pane, enter “eslint”. You should see a plugin at the top of the list called ESLint, by Dirk Baeumer. Click on it and click the Install button on the page that opens.
The plugin should automatically detect your ESLint install and configuration. Crate a new file in your project and test it out by putting in the following:
var foo = bar;
You should get two red squiggles, one under
foo and the other under
bar. If you hover your mouse over
foo you should see a popup with the message:
‘foo’ is assigned a value but never used.
and similarity with bar:
‘bar’ is not defined.
With some errors, there will be a light bulb you can click and get options to fix the error for you.