Vue Technical Debt Cleanup

Options API Bloat, Vuex Boilerplate, and Vue 2 End-of-Life Risk

Vue 2 apps accumulate debt in predictable ways. Large components with dozens of data properties, computed values, and methods that are logically unrelated but forced together by the Options API structure. You want to extract related logic, but mixins create implicit dependencies and naming collisions.

Vuex stores are often another pain point. Modules with mutations, actions, and getters for simple state that could be a reactive ref. The boilerplate overhead discourages proper state organization, so developers cram everything into one module rather than creating focused stores.

Compatibility Build Bridge, Incremental Composition API Conversion, and Pinia Migration

We migrate Vue 2 to Vue 3 using the compatibility build as a bridge. This lets you run Vue 3 with Vue 2 behavior for components that haven’t migrated yet. Then we convert components incrementally - starting with leaf components and working up the tree.

Options API converts to Composition API using <script setup> syntax. Related logic groups into composables. A component that had 15 data properties, 10 computed values, and 8 methods becomes three composables - each focused on one concern. Vuex migrates to Pinia, which is simpler, has better TypeScript support, and requires no mutations.

500-Line Components Become Five Composables and a 50-Line Template

Components become smaller and more focused. Logic that was scattered across data, computed, methods, and lifecycle hooks now lives in composables that can be tested independently. A 500-line component becomes five composables and a 50-line template.

Vue 3’s compiler produces smaller, faster output. The virtual DOM diffing is more efficient. Tree-shaking removes unused framework features from your bundle. Your app gets faster without any performance-specific optimization work - the framework upgrade handles it.

Replacing vue-cli with Vite and Vitest for Instant HMR and Faster Tests

Vue 2 projects typically run on webpack with vue-cli, a toolchain that is no longer maintained. Build times of 30 seconds or more for hot module replacement are common, and cold starts can exceed a minute on larger codebases. As part of the Vue 3 migration, we move your build pipeline to Vite.

The difference is not incremental. Vite uses native ES modules during development, so HMR updates reflect in the browser in under 100 milliseconds regardless of project size. Production builds use Rollup under the hood with automatic code splitting at route boundaries. The vite-plugin-vue ecosystem provides everything vue-cli offered — environment variable injection, CSS preprocessor support, static asset handling — without the configuration complexity that webpack accumulated over the years.

We also migrate test infrastructure from Jest with vue-test-utils to Vitest, which shares Vite’s transform pipeline. Tests run faster because they use the same module resolution as the dev server, and configuration stays in one place. Component tests use @vue/test-utils v2 with Composition API support, and we add snapshot tests for complex template rendering where visual regression matters.

Script Setup Enforcement, Typed Composables, and ESLint Rules That Block Options API Regression

We configure ESLint with vue3-recommended rules and enforce <script setup> syntax for new components. Custom rules prevent falling back to Options API patterns that create the same problems you just fixed.

TypeScript is added or strengthened throughout the migration. Vue 3’s Composition API was designed for TypeScript - generic components, typed composables, and proper prop inference work naturally. The type system catches refactoring mistakes and makes your codebase self-documenting.