Compilation step does not throw error when it should (TS2380)

[angelaraya]

Some getter/setters in the project should generate errors with TS2380 and stop compilation. The errors correctly surface when using sai-js as a dependency:

../sai-js/packages/data-model/dist/cjs/crud/resource.d.ts:18:9 - error TS2380: The return type of a 'get' accessor must be assignable to its 'set' accessor type
  Type 'undefined' is not assignable to type 'string'.

18     get registeredWith(): string | undefined;
           ~~~~~~~~~~~~~~

We should

• Identify why our build process (lerna run build) is not raising this errors
• Fix all the instances where the type mismatch happens.

[elf-pavlik]

We are looking into that, so far setting "skipLibCheck": false in the depended helps avoid compilation errors.

There seem to be some valid use cases where the getter can return undefined but the setter should be more strict (e.g. updatedAt is undefined until set on the first update). There are few relevant TS issues:

• Suggestion: allow get/set accessors to be of different types microsoft/TypeScript#2521
• Allow setter type to be incompatible with the getter type microsoft/TypeScript#43662

It looks like only the opposite is allowed where the setter can be loose and it normalizes the value for more strict getter.