Clear and concise description of the problem

As a developer using Vitest I want to read the current value of updateSnapshot in order to implement custom snapshot matchers following the update behavior of Vitests own snapshot matchers.

Suggested solution

Expose updateSnapshot as a public and typed property on SnapshotState, which can be accessed from Vitest matchers using expect.getState().snapshotState.

Currently, the value of updateSnapshot is only accessible through the internal property _updateSnapshot on snapshotState, which is not typed and can be subject to change.

Alternative

No response

Additional context

There is a related open issue regarding the --update flag, but is has a slightly different context and intention. That's why I opened a new issue. If you prefer, I'm open to add my request to the existing issue. In this case, you can close my request.

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.