feat: destroy a store with $dispose

[posva]

Close #557

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• Bugfix
• Feature
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change? (check one)

• Yes
• No

If yes, please describe the impact and migration path for existing applications:

The PR fulfills these requirements:

• When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx[,#xxx], where "xxx" is the issue number)
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Other information:

[codecov]

Codecov Report

Merging #597 (8c50e19) into v2 (2b3aa5f) will increase coverage by 0.11%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##               v2     #597      +/-   ##
==========================================
+ Coverage   89.70%   89.81%   +0.11%     
==========================================
  Files           9        9              
  Lines         369      373       +4     
  Branches       99       99              
==========================================
+ Hits          331      335       +4     
  Misses         14       14              
  Partials       24       24              

Impacted Files	Coverage Δ
packages/pinia/src/types.ts	100.00% <ø> (ø)
packages/pinia/src/store.ts	87.44% <100.00%> (+0.22%)	⬆️

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[sabifa]

How am I supposed to use disposePinia? It seems like I can't import it in any way.

[eastmann]

How am I supposed to use disposePinia? It seems like I can't import it in any way.

It seems you should distructure $dispose from your store instance:

import { onUnmounted } from 'vue'
import { useYourStore } from '@/stores/YourStore'
...
const { $dispose } = useYourStore()
...
onUnmounted(() => {
    $dispose()
})