store should support falsey state

[jbedard]

I'm submitting a...

[X] Bug report  

What is the current behavior?

Feature store/reducers with a falsey state fallback to the initial state. This might only be for feature and not root reducers?

See

platform/modules/store/src/reducer_manager.ts

Line 46 in 7f49b9f

state || initialState,

where state || initialState is used.

Expected behavior:

Any non-undefined state value should be considered "set" and not be reset to the initialState.

platform/modules/store/src/reducer_manager.ts

Line 46 in 7f49b9f

state || initialState,

should be changed to (state !== undefined) ? state : initialState

Minimal reproduction of the problem with instructions:

Can create one if necessary...?

Version of affected browser(s),operating system(s), npm, node and ngrx:

I'm using 5.x

Other information:

As an example... in my case this feature-store represents the user session. An empty store value (undefined) means the session state is unknown (not fetched yet), a null value means no session exists and a Session object means the user is logged in. In this case the null value is being converted to undefined.

[jbedard]

Actually... should initialState be the initial state, or the default state? Is it correct that an undefined store value should always be converted to the initialState like the feature store does (in one case) today?

[brandonroberts]

Fixed via #886