Change Session loading to return undefined when there is no Session

[thecodepixi]

WHY are these changes introduced?

We were previously returning null when no Session is found. We should instead return undefined

WHAT is this pull request doing?

Updates all Session loading implementation return types to Session | undefined

Type of change

• Minor: New feature (non-breaking change which adds functionality)

[tanema]

We should instead return undefined

Why?

[tanema]

I can see a lot of changes that are more linting than the specific change for this PR. Ideally these would be separate PRs (or at least only changing the code you touch) But it LGTM anyway 👍

[paulomarg]

The changes LGTM!

[thecodepixi]

I can see a lot of changes that are more linting than the specific change for this PR. Ideally these would be separate PRs (or at least only changing the code you touch) But it LGTM anyway 👍

Yeah, this seems to be happening to me a lot lately. I think we/I might have some linting inconsistencies so when I pull things down it gets formatted on my end. Will fix that ASAP.

[thecodepixi]

We should instead return undefined

Why?

My personal thinking here is that a session is almost always assigned to a variable, and if a variable has no value it is therefore undefined, and also that functions generally return undefined if there is no return value. My understanding of null is "intentional nothingness", and we expect that the session loading functions should return something, if they don't, the session is just undefined, rather than the session being null/nothing.