[shared_preferences] Test can detect that SharedPreferences is mocked.

[Hu1buerger]

Checking wheter a integration test using shared_preferences as the
storage backend should be able to check that the current instance is mocked.

Not checking could result in overriding could override app runtime data
or calling [setMockInitialValues] could lead to overriding data from the
test.

closes #1

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[stuartmorgan]

closes #1

This is not correct; could you provide the correct issue link please?

It's not clear to me from the description here what problem this is solving—I'm not sure what the case is where you are mocking values but don't know that you are mocking values—so an issue with more details is needed here.

It's also not clear to me why this needs a new API, rather than checking SharedPreferencesStorePlatform.instance directly.

[Hu1buerger]

@stuartmorgan Hu1buerger#1 here's the issue

[stuartmorgan]

@stuartmorgan Hu1buerger#1 here's the issue

That's an issue in your own repository, not a Flutter issue, and it doesn't address the questions in my comment.

[stuartmorgan]

Thank you for your contribution. I'm going to close this PR for now since there are outstanding comments, just to get this off our PR review queue. Please don't hesitate to submit a new PR if you have the time to address the review comments. Thanks!