Shared Dependencies

Shared dependencies are external libraries used across multiple design system packages. Managing shared dependencies effectively prevents version conflicts, reduces bundle bloat, and ensures consistent behavior throughout the system.

What Are Shared Dependencies

Shared dependencies are third-party libraries that multiple design system packages require. React, date libraries, or utility packages often fall into this category. When multiple packages depend on the same library, coordination becomes necessary to avoid problems.

Poor shared dependency management creates issues including version conflicts, duplicate code in bundles, and inconsistent behavior. Proper management addresses these problems through explicit coordination.

How Shared Dependencies Work

Peer dependency declaration indicates that packages expect consumers to provide shared dependencies. This approach avoids bundling shared code multiple times and ensures consistent versions. Peer dependencies require consumers to install the dependency themselves.

Version alignment coordinates which versions packages require. When packages require different versions of the same dependency, conflicts arise. Alignment ensures compatible requirements across packages.

Deduplication eliminates redundant dependency installations. Package managers attempt deduplication automatically when possible. Proper version alignment enables successful deduplication.

Compatibility testing verifies the system works with supported dependency versions. Testing should cover the full range of versions packages claim to support. Compatibility matrices document tested combinations.

Key Considerations

• Peer dependencies work well for dependencies consumers likely already have
• Version ranges should be realistic and tested
• Deduplication relies on compatible version requirements
• Breaking changes in shared dependencies affect the entire system
• Documentation should clarify dependency requirements

Common Questions

When should dependencies be peers versus bundled?

Peer dependencies suit libraries consumers typically provide, like React or Vue. Bundled dependencies suit specialized libraries consumers would not otherwise have. The choice affects bundle size, version consistency, and installation complexity.

How do organizations handle shared dependency updates?

Updates to shared dependencies require evaluating impact across all packages, testing compatibility, and coordinated releases if changes affect multiple packages. Automated dependency update tools can help manage this process.

What happens when packages need different versions?

Version conflicts may indicate that alignment is possible with updated dependencies, that the dependency should not be shared, or that architectural changes are needed. Conflicts require investigation and resolution rather than acceptance.

Summary

Shared dependencies require coordination across design system packages. Success demands peer dependency discipline, version alignment, and compatibility testing. Organizations should manage shared dependencies explicitly to avoid conflicts and inconsistencies.