ESLint helps in identifying and reporting problematic patterns in JavaScript code, which could lead to potential errors, bugs or unoptimized code.
To configure ESLint for JavaScript, follow the steps below:
1. First, ensure that Node.js and npm are installed. ESLint is available via npm and needs Node.js. You can download Node.js from their official website.
1. Install ESLint globally by running `npm install -g eslint` on your command line.
1. Navigate to your project directory and initialize ESLint using the command `eslint —init`. This will create a `.eslintrc` file which holds the configuration rules.
1. The `eslint —init` command triggers a few questions such as:
- How would you like to use ESLint?
- What type of modules does your project use?
- Which framework does your project use?
- Does your project use TypeScript?
- Where does your code run?
- What format do you prefer for your config file to be in?
Answer these questions based on the requirements of your project.
1. Once the `.eslintrc` file is created, you can edit it and specify your rules. ESLint comes pre-configured with a set of rules that you can modify or extend as per your needs.
1. To manually edit rules, open `.eslintrc` file and set your rules. For example:
```
{
“rules”: {
“semi”: [“error”, “always”],
“quotes”: [“error”, “double”]
}
}
```
In the above example, `semi` and `quotes` are rule IDs, `error` is the level for the rule, and `always` and `double` are the options for the rule.
1. Lastly, to run ESLint on your JavaScript file, use the command `eslint yourfile.js`. Replace `yourfile.js` with the actual name of your file.
Remember, the goal is not to disable ESLint or to constantly change configuration to get rid of errors, but to improve the code quality as guided by ESLint. Customize rules according to your coding standards or team’s conventions but try to follow ESLint’s recommendations for a better and cleaner code.
