The Top 5 Node.js Linters

A linter is an essential tool in modern programming, helping you find and fix problems early in your development process. Due to the flexible nature of JavaScript and the widespread nature of Node.js, code consistency can be a challenge. Using a linter reduces the risk of avoidable bugs getting into your production codebase.

The following linters deserve a place on this list based on several important criteria. These include popularity, speed, ease of use, customizability and adaptability.

ESLint is an open-source, configurable Node.js linter. It finds issues such as possible runtime bugs, best practice violations, invalid syntax, and code style issues.

The linter has a wide variety of built-in rules that you can configure to enforce coding conventions and detect potential errors. The built-in rules include:

• Implementation of consistent indentation.
• Require strict equality (===) instead of loose equality (==).
• Check potential security vulnerabilities, such as the declaration of unused variables.

Typically, you store ESLint rules in a configuration file, which can be in different formats. It can include settings for built-in rules, plugins with custom rules, and shareable configurations, such as the popular Airbnb JavaScript style guide.

Setting up ESLint can be a daunting and time consuming task, with a lot of configuration to specify your requirements. But you can use the ESLint CLI tool to quickly integrate ESLint into your project and then add or remove lines as needed.

ESLint may not be suitable for all projects, especially small or simple projects. You may not be able to justify the overhead of setting up and configuring ESLint. It is ideal for large projects with diverse teams, where code quality and consistency are top priorities.

JSLint is a strict linter that enforces a specific set of rules for writing JavaScript code. These rules cover a wide variety of issues, some of which include:

• Enforce the use of semicolons.
• Require braces around conditional statements and loops.
• Preventing the use of specific language features, such as the use of the var keyword, which can affect how hoisting works, leading to unexpected behavior.

Integrating JSLint into a codebase is relatively easy and requires little or no configuration to fluff your code. One way you can achieve this is by using the command line tool. You can pass your JavaScript files to the JSLint command line utility, which will output any errors or warnings.

Although you can integrate JSLint into your codebase, it is less flexible than other linters such as ESLint due to its limited customization options. However, it offers integrations for various code editors, making it easy to incorporate into your workflow.

Since JSLint has a limited set of rules and does not support custom rules or plugins, it may not be suitable for complex projects that require more flexibility and a lot of customization.

Overall, JSLint is a useful tool for enforcing a specific set of coding standards and best practices. Still, it may not be ideal for all projects due to the lack of customization and flexibility.

JSHint is a tool that analyzes JavaScript code and identifies common errors and potential bugs. It can detect various issues such as syntax errors, implicit type conversions that may cause bugs, variables that may leak, and many other errors.

It was created to serve as a more configurable version of JSLint, with support for several JavaScript environments and frameworks, including Node.js, jQuery, and QUnit, among others.

Similar to ESLint, JSHint also provides a set of built-in rules that you can configure to enforce coding conventions and detect possible errors, such as missing semicolons, unused variables, and undefined functions.

However, unlike ESLint, JSHint does not support custom rules, limiting your linting to rules provided by JSHint.

JSHint is relatively easy to use compared to JSLint and works well out of the box, requiring minimal configuration to get started. It is ideal for small to medium sized projects where the main goal is to spot common coding errors and enforce good coding practices.

quick-lint-js is a lightweight and fast linter for JavaScript. According to quick-lint-js benchmarks, it’s about 130 times faster than ESLint, so it’s the ideal linter for projects where speed and efficiency are paramount.

quick-lint-js gives you instant linting feedback as you code. It owes its speed to its minimalist design, with less infrastructure and fewer components. This allows quick-lint-js to manage and reduce runtime parsing costs and, by extension, parse your code faster than most linters in the Node.js ecosystem.

quick-lint-js works out of the box without any additional configuration and specifies good presets for most of its rules. However, you can still customize it using a quick-lint-js.config file.

It also provides integration support in the form of plugins for various IDEs, including VsCode, Vim, Neovim, Sublime Text, and Emacs, among others. It also comes with a fully featured command line tool to help you with your linting. This tool is available for GNU/Linux, macOS and Windows operating systems.

In general, quick-lint-js is ideal for fast-moving projects, regardless of their size. While it is important to note that this tool is relatively new compared to other linters discussed in this article, so it can be difficult to find help when you encounter errors that are not extensively covered in their documentation.

StandardJS is a JavaScript linter that emphasizes a consistent and idiosyncratic coding style. It enforces a set of preset built-in formatting and styling rules that promote consistency across all the code bases you use.

StandardJS saves a lot of time and reduces the number of code style decisions you have to make by providing a strict and standardized approach. One of the main features of StandardJS is its “zero configuration” approach, which means no configuration file is required before you can use it.

Once installed, you just need it standard command to sift and reference the exact location of style violations in all JavaScript files in your working directory.

By enforcing a strict and standardized approach to coding style, StandardJS reduces the need for developers to spend time discussing the best way to format code. This means teams can focus on writing high-quality code that is consistent and easy to maintain over time.

However, a possible drawback of StandardJS is its strict adherence to a specific coding style. This may not be ideal for all development teams, especially those who prefer a more flexible or adaptable approach to code style.

Choose a good Linter that works for you

There are several linting tools available for Node.js, each with its own strengths and weaknesses. ESLint is a highly customizable and widely used linter with extensive linting capabilities and many built-in rules.

JSLint is a strict linter that leaves little room for customization, but is easy to use and integrates well into codebases. JSHint is a flexible linter that balances customization and ease of use. quick-lint-js is very fast, while StandardJS is a no-configuration linter that emphasizes following a specific set of conventions.