At the basic level, a linter is a tool within static code analysis that examines source code to flag mistakes, anomalous code, probable bugs, stylistic errors, and anything that deviates from the coding standards your team has agreed on. This could be as simple as a spelling error or highlighting problems like license incompatibility. It just depends on your use case.

Linters can analyze your codebase before you execute, which helps you improve your codebase in the early stages of development and beyond. Although code quality is important at every stage, this early stage in particular is where you can save yourself the most trouble down the line.

The simple answer is that linters help you achieve clean code. So beyond the obvious benefits of more maintainable and sustainable code, it also leads to better product performance and a range of other benefits for diligent dev teams.

This list includes everything from helping you enforce coding standards, to improving code quality, weeding out errors, and saving you endless hours of overtime and stress spent on emergency fixes.

Now that we’ve covered what linters are and what they do, it’s time to explore these use cases in action.

Code linters can work in various ways, but for the sake of this guide, we’ll look at some of the most common practical applications.

• Parsing code: This is the process of “understanding” the structure of the source code and what it means. One method of achieving this is through lexical analysis.

In this case, the source code will get broken down into tokens like keywords, identifiers, operators, literals, and even punctuation (in other words, the smallest parts). From there, the linter can read the code and create an abstract syntax tree (AST) – this basically shows which data is most important in the source code.

• Applying rules: The linter crosschecks this syntax tree in relation to the ruleset. Sometimes the rules can be customized, as is the case with Qodana.
• Reporting issues: The linter’s going to pick up on deviations here and generate a report that shows you what the issues are as well as where they are located in the code and, in a best-case scenario, what corrections you could make and why.

It’s also worth noting that linters can be integrated into text editors and CI/CD pipelines (as is the case with Qodana) and all sorts of developer environments, which means you can get real-time feedback on flagged issues and what needs to change.

If you’re interested in code quality and improving productivity in your team, JetBrains Qodana has you covered. Qodana linters offer you a variety of inspections for several programming languages. It’s also a useful tool for setting up quality gates in your CI/CD pipeline and collaborating on creating better-performing products.