Pinia Skilld

vuejs/pinia pinia@3.0.4

Tags: next: 2.0.0-rc.10, beta: 2.1.8-beta.0, latest: 3.0.4

References: Docs

API Changes

This section documents version-specific API changes — prioritize recent major/minor releases.

• BREAKING: defineStore({ id: 'storeName', ... }) — object signature with id property removed in v3.0.0; use defineStore('storeName', { ... }) instead. Old object syntax silently compiled but is now a runtime error source

• BREAKING: PiniaStorePlugin type — removed in v3.0.0; use PiniaPlugin instead. Code using PiniaStorePlugin will fail to compile source

• BREAKING: Vue 2 support dropped in v3.0.0 — Pinia v3 requires Vue 3 only. Users on Vue 2 must stay on Pinia v2 source

• BREAKING: TypeScript 5 or newer required in v3.0.0 — uses native Awaited type introduced in TS 4.5; TS 5+ recommended source

• BREAKING: IIFE bundle no longer bundles Vue Devtools in v3.0.0 — devtools API was too large; must be included manually depending on your workflow source

• BREAKING: Package is now published as type: module in v3.0.0 — CJS dist files still provided but the package root is ESM. May break setups relying on implicit CJS resolution source

• NEW: action(fn, name?) helper in setup stores — added in v2.2.0, available via SetupStoreHelpers parameter. Wraps a function so it is tracked by $onAction when called within the store; intended for advanced use cases like Pinia Colada source

• NEW: disposePinia(pinia) — added in v2.1.7, stops the pinia effect scope and removes state, plugins, and stores. Useful in tests or multi-pinia apps; disposed instance cannot be reused source

• NEW: SetupStoreDefinition<Id, SS> type — added in v2.1.7 for the return type of defineStore() when using a setup function. Extends StoreDefinition and enables better IDE support for setup stores source

• NEW: mapWritableState now picks up writable computeds in setup stores — added in v2.3.0. Previously only ref state was mapped; WritableComputedRef returns from setup stores are now included source

Also changed: mapGetters DEPRECATED (alias for mapState, still exported) · getActivePinia() returns Pinia | undefined (typed more strictly since v2.0.35) · skipHydrate(obj) stable — skips SSR hydration for non-state objects returned from setup stores · shouldHydrate(obj) exported utility for plugin authors

Best Practices

• Use $patch() with a function callback rather than an object when mutating arrays or performing multiple related changes — the function form groups all mutations into a single devtools entry and avoids creating intermediate collections source

• Use $subscribe() instead of watch() on store state — subscriptions fire only once per $patch call regardless of how many individual properties changed, avoiding redundant callbacks when using the function form of $patch source

• Pass { detached: true } to $subscribe() and true as the second arg to $onAction() when you need listeners to outlive the component — by default both are automatically removed on component unmount source

• In setup stores, use skipHydrate() to wrap state properties that must not be picked up from SSR initial state (e.g., composables backed by localStorage, client-only refs) — without it, the server's serialized value will override the intended client-side source source

tsCopy code
return {
  lastColor: skipHydrate(lastColor), // won't be overwritten by SSR state
  open,
}

• When a plugin adds new state properties, set the value on both store.$state (for SSR serialization and devtools) and store via toRef(store.$state, 'key') — setting only one breaks devtools display or reactivity sharing source

• Wrap non-reactive external objects (router, class instances, third-party lib instances) with markRaw() before assigning them in plugins — prevents Vue from trying to deeply observe objects that aren't meant to be reactive source

• When composing stores that reference each other, place useOtherStore() calls before any await in async actions — after an await the active pinia context may have changed, causing the wrong instance to be returned in SSR source

• Use createTestingPinia() from @pinia/testing for component tests rather than createPinia() — it stubs all actions by default and makes them inspectable as spies; pass plugins via the plugins option, not via testingPinia.use() source

• In options store getters, prefer arrow functions that receive state as the first parameter over regular functions using this — arrow function return types are inferred automatically, while this-based getters require an explicit return type annotation source