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[0.18.1] TypeError: Symbol.hasInstance is read-only

See original GitHub issue

Describe the bug

My tests that use vi.mock (in this case, mocking out the ora module) started failing as of vitest v0.18.1 with the following error:

TypeError: Cannot assign to read only property 'Symbol(Symbol.hasInstance)' of function 'function(...o) {
    if (e.called = !0, e.callCount++, e.calls.push(o), e.next) {
      let [s, l] = e.next;
  ...<omitted>... }'

In the reproduction (below), it presents itself as simply: TypeError: Symbol.hasInstance is read-only

I’m assuming this is related to PR #1648 but I’m not sure if I need to update my usage to comply with the intent of the PR or what.

Reproduction

https://stackblitz.com/edit/vitest-dev-vitest-ht4a9x?file=test/mock.test.ts&view=editor

System Info

System:
    OS: Windows 10 10.0.19044
    CPU: (16) x64 Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz
    Memory: 17.74 GB / 31.92 GB
  Binaries:
    Node: 16.16.0 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.22.18 - ~\AppData\Roaming\npm\yarn.CMD
    npm: 8.12.2 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Chrome: 103.0.5060.114
    Edge: Spartan (44.19041.1266.0), Chromium (103.0.1264.62)
    Internet Explorer: 11.0.19041.1566
  npmPackages:
    vitest: 0.18.1 => 0.18.1

Used Package Manager

npm

Validations

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Read the Contributing Guidelines.
Read the docs.
Check that there isn’t already an issue that reports the same bug to avoid creating a duplicate.
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The provided reproduction is a minimal reproducible example of the bug.

Issue Analytics

State:
Created a year ago
Reactions:9
Comments:9 (6 by maintainers)

Top GitHub Comments

1reaction

sheremet-vacommented, Jul 26, 2022

Please, don’t post comments like “still not working”. When someone will work on a fix, it will be displayed here.

0reactions

simon-abbottcommented, Aug 4, 2022

Figured out a fix! #1786.

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