Strict null checking

[anthonydresser]

We should start looking at enforcing strict null check on our typescript files similar to vscode (microsoft/vscode#60565). This helps catch errors due to our code hitting paths where we try and access a null object.

[anthonydresser]

@kburtram @MattIrv thoughts?

[kburtram]

@anthonydresser in general I like this idea. Though I would probably wait for VS Code to complete any required work on their side and we pick-up that up in a refresh (if applicable). And we need to look at the amount of accumulated debt and when to schedule relative to rest of our fundamentals backlog.

[MattIrv]

It's worth bringing this in since VS Code is already doing it and it should be pretty easy to run the same tasks for our build.

I am a bit worried about it since these issues won't get caught in our regular yarn run watch workflow, right? But as long as it's included in our azure pipelines definition that should be good

[anthonydresser]

Vscode has a command to scan certain files and apply the strict-null-check tslint config. So it's something they are doing slowly, catching up on debt, then when they have all their existing code enabled they will add it to their default tslint. We could take that approach.

[kburtram]

Closing older issues.