Refactor Wrapper to Injected Service (WrapperFactory)

[georg-schwarz]

In the process of #427, I noticed there are some dependency cycles that cannot be resolved with ESM modules.

This PR explores whether we can remove some dependency cycles by using the dependency injection mechanism of Langium. Instead of using exported instances for singletons, I registered the following services:

export interface JayveeAddedServices {
  // ...
  operators: {
    TypeComputerRegistry: OperatorTypeComputerRegistry;
    EvaluatorRegistry: OperatorEvaluatorRegistry;
  };
  WrapperFactory: WrapperFactory;
  // ...

In terms of specific dependency cycles, this PR tackles cycles when the instances unaryOperatorRegistry, binaryOperatorRegistry, ternaryOperatorRegistry were imported. Instead, the service interface is injected, so the transpiler only needs to import the type and not the instance.

[georg-schwarz]

@rhazn @joluj Is this a refactoring that you would welcome?

If yes, I'd go ahead and proceed with all the remaining wrappers as well.

[joluj]

I'm (almost) always pro DI, so go for it.

[rhazn]

Hard to evaluate because of the huge changeset, but in general I am also happy with it. I'd question why you have a JayveeAddedServices object and not just use the DI for each service independently (what does bundling them all into one object accomplish?). But regardless what the answer to that question is, I am happy with your choice ;).

[georg-schwarz]

Hard to evaluate because of the huge changeset, but in general I am also happy with it.

I'd say the design becomes a little more complex and more rigid (as you can't just access the wrappers from anywhere).

I'd question why you have a JayveeAddedServices object and not just use the DI for each service independently (what does bundling them all into one object accomplish?).

That stuff comes with Langium. It think this is a "poor man's version of DI". Instead of passing the dependent objects to the constructor, you pass all available objects via a DI container and let the constructor choose what it needs...
The JayveeAddedServices is a type we union with the DI container that comes with Langium. For more info, see here.
I'd just go with that design.

[rhazn]

Ja, sounds fair. If it is actually the design langium suggests, we should capture that in a comment (with a link as you did here) in the JayveeAddedServices class.

[rhazn]

Otherwise I am happy with this.

[georg-schwarz]

This code snippet exists at a plethora of places. Can we move to a method?

[georg-schwarz]

Done in 8db76f0.

[georg-schwarz]

I decided to explicitly not cover ValueTypes in this PR not further to bloat up the PR.
Refactoring them accordingly should be subject to a future PR, that is hopefully able to resolve some more dependency cycles.

[georg-schwarz]

For a code review, I recommend to first look into the following changes before skimming over the import and parameter changes:

• Addition of services for dependency injection in libs/language-server/src/lib/jayvee-module.ts
• Separation of OperatorEvaluatorRegistry and OperatorTypeComputerRegistry in libs/language-server/src/lib/ast/expressions/operator-registry.ts
• Introduction of the WrapperFactory forwarding to the wrappers (that are now only exported as types in the corresponding index.ts to avoid manual creation without the factory: libs/language-server/src/lib/ast/wrappers/wrapper-factory.ts
• Usage of added services and introduction of JayveeValidatinProps to simplify the JayveeValidationCheck type in libs/language-server/src/lib/validation/validation-registry.ts
• The remaining changes should follow from the changes above (adapted usage / creation)

Most representative commits to understand what happened chronologically:

1. Break up some dependencies in the expression directory - ea89232
2. Inject evaluator and type computer registry as service - e593726
3. Introduce WrapperFactory for creating BlockTypes and TypedObjects - 15a1213
4. Envorce WrapperFactory over BlocktypeWrapper and ConstraintTypeWrapper - 93e824f
5. Simplify validation methods by introducing JayveeValidationProps as generalized parameter - 8db76f0