[cryptodev-2s]

Explanation

The utils UUID mock uses vi.fn().mockImplementation(actual.v4). With the shared mockReset: true setting, Vitest resets that mock to return undefined. Calling createSandbox() inside a test without overriding the UUID then throws when constructing the directory path.

Pass the real implementation directly to vi.fn(actual.v4) so mock resets restore it. A MockedFunction assertion preserves UUID's overloaded signatures. Add a regression test that creates two sandboxes without overriding UUID and checks that their directories differ; this test fails before the fix and passes afterward.

References

• Follow-up to test: run utils on Vitest #10871.
• Related: test: use typed Vitest module mock factories #10904, which updates the remaining typed mock factories separately.

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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Note

Low Risk
Test-only changes to Vitest mocking in fs.test.ts; no production code paths affected.

Overview
Fixes the uuid v4 mock in fs.test.ts so Vitest’s mockReset behavior does not leave v4 returning undefined after a reset. The mock now uses vi.fn(actual.v4) with a MockedFunction cast instead of mockImplementation, so resets restore the real UUID generator.

Adds a createSandbox regression test that creates two sandboxes without stubbing v4 and asserts their directoryPath values differ (fails under the old mock setup).

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