How to Use Deno Lint: Syntax, Example, and Tips

Use deno lint in your terminal to check your Deno project files for style and coding issues. You can run deno lint [file] to lint a specific file or just deno lint to lint all supported files in the current directory.

Syntax

The basic syntax for using Deno lint is simple:

• deno lint: Lints all supported files in the current directory and subdirectories.
• deno lint [file]: Lints a specific file.
• deno lint --json: Outputs lint results in JSON format.
• deno lint --rules: Lists all linting rules available.

You can add flags to customize linting behavior.

bash

deno lint [options] [files...]

Example

This example shows how to lint a single file named example.ts. It will check the file for style and error issues and print the results in the terminal.

bash

deno lint example.ts

Output

Check file: example.ts
No lint errors found.

Common Pitfalls

Common mistakes when using deno lint include:

• Running lint without specifying files in a large project, which can take longer.
• Ignoring lint warnings that help keep code clean and consistent.
• Not updating Deno to the latest version, missing new lint rules.

Always review lint output carefully and fix issues to improve code quality.

bash

Wrong usage:
deno lint example.ts

Right usage:
deno lint example.ts

(Note: The correct command is <code>deno lint</code> with a space.)

Quick Reference

Command	Description
deno lint	Lint all supported files in the current directory
deno lint example.ts	Lint a specific file named example.ts
deno lint --json	Output lint results in JSON format
deno lint --rules	Show all available linting rules

Key Takeaways

Run deno lint to check your code for style and errors easily.

You can lint specific files by adding the file name after the command.

Use deno lint --rules to see all lint rules you can follow.

Always fix lint warnings to keep your code clean and consistent.

Keep Deno updated to use the latest linting features and rules.