Virtual module mocking issue in Vitest 4

[HiDeoo]

Describe the bug

This discussion is a follow-up to this discussion that I initially opened before this issue._

In a test file, I have different describe blocks where in each of them, I mock a virtual module, e.g. using vi.doMock() and mock a function from that virtual module making it return different values.

The behavior seems to be different between Vitest 3 and Vitest 4:

• Vitest 3: everything seems to work as expected, and calling some code that uses that virtual module returns the mocked value.
• Vitest 4: the first mocked value seems to be returned for all tests.

Reproduction

I've setup a minimal repro available here: https://github.com/HiDeoo/vitest-4-mock-repro

1. Clone the repository
2. Run pnpm install
3. Run pnpm test

Some tests that are checking that the expected returned mocked value is correct will fail.

A few extra notes:

• Running pnpm add vitest@3 and pnpm test will make the test pass
• I tried swapping the order of vi.resetModules() and vi.doMock() as suggested but this didn't change the behavior

System Info

System:
    OS: macOS 26.3
    CPU: (8) arm64 Apple M1
    Memory: 197.14 MB / 16.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 22.14.0 - /Users/hideoo/.local/state/fnm_multishells/36543_1772008897917/bin/node
    npm: 10.9.2 - /Users/hideoo/.local/state/fnm_multishells/36543_1772008897917/bin/npm
    pnpm: 9.15.9 - /Users/hideoo/.local/state/fnm_multishells/36543_1772008897917/bin/pnpm
    bun: 1.3.9 - /opt/homebrew/bin/bun
  Browsers:
    Firefox: 147.0.4
    Safari: 26.3
  npmPackages:
    vitest: ^4.0.18 => 4.0.18

Used Package Manager

pnpm

Validations

• Follow our Code of Conduct
• 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.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[hi-ogawa]

This is only happening with virtual modules, so this is not an intended behavior.