fix: clarify in-memory provider reqs (#277)

Minor clarifications to the in-memory provider, especially around `flags
changed` which at the moment is not consistently implemented.

---------

Signed-off-by: Todd Baert <[email protected]>
Co-authored-by: Michael Beemer <[email protected]>
Co-authored-by: Lukas Reining <[email protected]>

Author: 3 people

specification/appendix-a-included-utilities.md

@@ -16,13 +16,14 @@ This document contains requirements for auxiliary utilities provided by the SDK,
 The in-memory provider is intended to be used for testing; SDK consumers may use it for their use cases.
 Hence, the packaging, naming, and access modifiers must be set appropriately.
 
-Given below are features this provider **MUST** support,
-
-- Provider must be initiated with a pre-defined set of flags provided to a constructor
-- Feature Flag structure must be minimal but should help to test OpenFeature specification
-- EvaluationContext support should be provided through callbacks/lambda expressions
-- Provider must support a means of updating flag values, resulting in the emission of `PROVIDER_CONFIGURATION_CHANGED` events
-- Provider must be maintained to support specification changes
+This provider **MUST** have the following features:
+
+- The provider is initiated with a pre-defined `flag set` provided in the constructor.
+- The flag structure must be minimalist and should help test the OpenFeature specification.
+  - EvaluationContext support should be provided through callbacks/lambda expressions.
+- The provider must support a means of updating the `flag set`, resulting in the emission of `PROVIDER_CONFIGURATION_CHANGED` events.
+  - The change event should consider all flags changed; a union of all previous and all new flag keys should be supplied in the `flags changed` field.
+- The provider must be maintained to support specification changes.
 
 ## SDK end-to-end testing