Component Linting Rules

Component linting rules enforce design system standards through automated code analysis. These rules detect patterns that indicate potential drift, non-compliance, or suboptimal component usage. Integrating linting into development workflows catches issues early when correction is easiest.

What Are Component Linting Rules

Component linting rules are automated checks that analyze code for design system compliance. Linters parse source code and evaluate it against defined patterns. Rules might check for hardcoded values that should reference tokens, disallowed component imports, incorrect prop usage, or forbidden styling patterns. Violations produce warnings or errors during development.

Linting rules complement other enforcement mechanisms. While visual regression testing catches appearance drift and integration testing verifies behavior, linting catches code-level patterns regardless of runtime manifestation. Rules operate during development, providing immediate feedback before code reaches review or CI.

How Component Linting Rules Work

Rule definition specifies what patterns to detect and how to respond. Rules are typically defined in configuration files that linting tools consume. Definition includes the pattern to match, the message to display, and the severity level (warning or error). Custom rules extend linter capabilities beyond built-in checks.

Pattern detection uses abstract syntax tree (AST) analysis to examine code structure. Linters parse code into ASTs representing its logical structure. Rules traverse ASTs looking for patterns matching their definitions. This structural approach enables sophisticated pattern matching beyond simple text search.

IDE integration surfaces violations during development. Editor plugins connect to linting tools, displaying warnings and errors inline as developers write code. This immediate feedback catches issues at the earliest possible point. IDE integration typically highlights violations and provides quick-fix suggestions.

CI integration enforces standards at the repository level. Linting runs as part of continuous integration, failing builds when violations exceed thresholds. CI enforcement prevents violations from merging even if developers ignore IDE warnings. Configuration can distinguish between blocking errors and advisory warnings.

Auto-fixing automatically corrects certain violations. Some patterns have unambiguous corrections that tools can apply automatically. Auto-fix capabilities reduce developer burden for mechanical compliance tasks. Not all violations are auto-fixable; some require human judgment.

Key Considerations

• Rule severity should match violation importance; not everything warrants blocking errors
• Custom rule development requires understanding linter internals and AST patterns
• Rule maintenance is needed as design system standards evolve
• Too many rules create noise that developers ignore
• Rule documentation helps developers understand and comply

Common Questions

What types of component linting rules provide the most value?

High-value rules typically address patterns with clear compliance criteria and meaningful impact. Hardcoded value detection finds colors, spacing, and typography values that should reference tokens. Component import restrictions prevent usage of deprecated or disallowed components. Prop validation ensures required props are provided and prop values are valid. Styling pattern restrictions catch forbidden approaches like inline styles or certain CSS-in-JS patterns. Accessibility checks catch missing ARIA attributes or improper semantic HTML. These categories address common drift sources with clear, automatable detection criteria.

How should teams develop and maintain custom linting rules?

Custom rule development requires several considerations. Start with clear problem definition: what specific pattern should the rule detect, and why does it matter? Study existing rules as models for implementation patterns. Test rules against real codebases to verify they catch intended violations without excessive false positives. Document rules clearly so developers understand what is required and why. Establish review processes for new rules to ensure quality. Plan for maintenance as standards evolve; rules need updates when requirements change. Monitor rule effectiveness through violation metrics; rules that never fire or always fire may indicate problems. Share rules across teams through published packages to spread value beyond their creators.

Summary

Component linting rules enforce design system standards through automated code analysis that detects patterns indicating drift or non-compliance. Rules operate through pattern detection using AST analysis, with integration into IDEs for immediate feedback and CI pipelines for enforcement. High-value rules address hardcoded values, import restrictions, prop validation, styling patterns, and accessibility checks. Custom rule development requires clear problem definition, testing, documentation, and ongoing maintenance as standards evolve.