Reactive regression on 3.4.15

[lehni]

Vue version

3.4.15

Link to minimal reproduction

https://play.vuejs.org/#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

Steps to reproduce

Just open the reproduction and see the recursive updates in action.

What is expected?

The same as on v3.4.14 and lower: Only one update should occur.

What is actually happening?

The getter modifies the state before returning it, and this triggers reevaluation of the getter after the call, getting it caught in an infinite update loop.

System Info

System:
    OS: macOS 14.2.1
    CPU: (14) arm64 Apple M3 Max
    Memory: 308.45 MB / 36.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.6.1 - ~/.nvm/versions/node/v20.6.1/bin/node
    Yarn: 1.22.19 - ~/.nvm/versions/node/v20.6.1/bin/yarn
    npm: 9.8.1 - ~/.nvm/versions/node/v20.6.1/bin/npm
    pnpm: 7.30.0 - ~/.nvm/versions/node/v20.6.1/bin/pnpm
    bun: 1.0.11 - ~/.bun/bin/bun
  Browsers:
    Chrome: 120.0.6099.129
    Chrome Canary: 122.0.6225.0
    Firefox Nightly: 113.0a1
    Safari: 17.2.1
    Safari Technology Preview: 17.4

Any additional comments?

I am fairly confident that this regression was introduced by:

#10123 / bcdecb7

[Doctor-wu]

Computed was updated in recent versions, and I believe this is the expected result in your reproduction. You are not supposed to make effects in your computed function.

[sodatea]

Expected. Such usage is explicitly documented as a bad practice: https://vuejs.org/guide/essentials/computed.html#getters-should-be-side-effect-free