Debugging Linting Issues

Common issues

Config not found, parser errors, plugin conflicts, and rule misconfigurations are common. Use debug mode to trace issues.

Debugging techniques

Use debug flag and --print-config to diagnose issues.

# Enable debug output
DEBUG=eslint* eslint .

# Print effective config for a file
eslint --print-config src/app.js

# Test a single file with verbose output
eslint src/app.js --debug

# Check plugin loading
eslint --print-config src/app.js | grep -A 5 plugins

Output:

Debug output shows config and plugin info

Use CLI vs config

If a rule works via CLI (eslint --fix) but not in your config, check for syntax errors in .eslintrc.json. Validate JSON or YAML.

Quick check

Quick check: How do you debug ESLint config issues?

• Use DEBUG=eslint* or eslint --print-config to see active rules.
• Guess and try random configs.
• Restart the editor.