SessionManager does not work when FeatureDefinition is null

[apetukhov]

We use a ISessionManager to maintain a consistent flag state across child requests. If somewhere is no FeatureDefinition, the result of checking the flag in one service may differ from the result in another within the same logical operation.

The behavior changed in version 4 of the package.

[zhiyuanliang-ms]

Hey, @apetukhov

I found that we unintentionally introduced a behavior change in v4.

In v3, even if FeatureDefinition is null, the session manager will still be used for evaluation result.

In v4, the session manager will be skipped if FeatureDefinition is null.

This is an oversight. Sorry for the inconvenience.

[zhiyuanliang-ms]

@jimmyca15 @rossgrambo
I think ISessionManager should be also able to cache variant.

[jimmyca15]

@jimmyca15 @rossgrambo I think ISessionManager should be also able to cache variant.

It's a breaking change to add to the existing interface, but we could add a new one. But it's a separate issue.