The Sto upgrade guide helps you modernize legacy JavaScript projects with a clear migration path and reduced runtime errors. Each step in this guide focuses on compatibility, performance, and long term maintainability.
Use this resource to plan version upgrades, configure tooling, and validate builds before production deployment.
| Upgrade Phase | Goal | Key Tooling | Success Indicator |
|---|---|---|---|
| Environment Audit | Identify runtime and dependency constraints | Node.js, npm/yarn, browserslist | Clear compatibility matrix |
| Codebase Preparation | Refactor deprecated APIs and module syntax | ESLint, TypeScript, Babel | Zero critical lint errors |
| Dependency Update | Upgrade libraries to latest stable versions | Dependabot, Renovate, npm cli | All packages on semver patch |
| Build & Test Validation | Ensure tests pass and bundles shrink |
Planning Your Sto Upgrade Path
Define Target Versions and Constraints
Start by documenting current Sto version, Node.js runtime, and supported browsers. Define target versions using semantic versioning ranges and prioritize backward compatibility for legacy consumers.
Migration Strategy and Module Refactoring
Convert CommonJS to ECMAScript Modules
Replace require/exports with import/export syntax to enable tree shaking and better runtime optimization. Update any dynamic imports and ensure default exports align with library expectations.
Adapt to New APIs and Lifecycle Hooks
Sto introduces refined lifecycle hooks and configuration objects. Map old event names to new typed callbacks and validate configuration shapes with TypeScript or runtime checks.
Build, Test, and Performance Validation
Run Automated Tests Under Real Conditions
Execute unit, integration, and e2e suites with the upgraded Sto version. Measure build size, runtime latency, and memory usage to catch regressions early.
Enable Production Safeguards
Turn on strict mode, minification, and source maps in staging. Monitor error tracking in real user monitoring tools before full rollout.
Deployment and Rollback Planning
Stage Release with Feature Flags
Deploy upgrades behind feature flags to a subset of users. Verify logs, performance metrics, and business KPIs before full activation.
Prepare Rollback Procedures
Keep previous build artifacts and database migrations reversible. Document one click rollback steps for operations teams to reduce outage risk.
Recommended Practices for Long Term Maintenance
- Pin exact dependency versions in lockfiles for reproducible builds
- Automate upgrades with Dependabot and review changes in pull requests
- Run compatibility checks against target browsers and Node.js LTS
- Monitor production metrics and log errors after each deployment
- Document migration decisions and API changes for future teams
FAQ
Reader questions
How do I resolve breaking API changes after upgrading Sto?
Review the official migration guide, replace deprecated methods with new equivalents, and add integration tests for each affected workflow.
Can I upgrade Sto in a monorepo with mixed versions?
Yes, use workspace protocols, lockfile version consistency, and incremental upgrades per package while maintaining shared tooling configuration.
What should I do if my tests fail due to timing differences?
Increase test timeouts where appropriate, audit asynchronous lifecycle hooks, and ensure mocks return stable promises that resolve in the expected order.
How can I verify that my bundle size did not increase unexpectedly?
Compare production bundles with size-limit or webpack-bundle-analyzer, audit imported features, and remove any unused polyfills or heavy plugins.