Feature Request: Export getSchema, hasSchema functions

[codeandcats]

Summary

• Added getSchema to Joiful class and exported it from the default instance in index.ts

  • getSchema simply calls existing internal getJoiSchema function

  • Changed the default behaviour of getJoiSchema to return undefined rather than an empty object schema if there is no working schema for the given class or it's ancestors.

• Added hasSchema to Joiful class and exported it from the default instance in index.ts

  • Simply returns boolean for whether a class has a schema (any decorators) or not.

• Changed the default behaviour of the validator functions (validate, validateAsClass, validateArrayAsClass) so that they will error (with NoValidationSchemaForClassError) when trying to validate against a class that has no schema associated with it. This will be a breaking change and will trigger a major version bump when releasing.

Motivation

@stepanzabelin wanted a way to tell if a class has a schema associated with it (see #105). This PR addresses this issue by exporting a hasSchema function that returns whether a class has a schema or not.

Ticket

Closes #105.

[codeandcats]

If/once we're happy for this to go in I'll follow it up with a new release.

[stepanzabelin]

:fire::fire::fire: Thank you @codeandcats

[laurence-myers]

Just wondering, does it make sense for validation to pass when validating against a class that has no validation schema/metadata? To me, this suggests a bug, like someone forgot to define the validation schema.

[codeandcats]

That's a fair question @laurence-myers.

I think I prefer the idea of it passing validation as then it doesn't require the consumer to have an extra step to check if it has a schema or not.

But I don't have a strong opinion on it and happy to change it. So would you say you are leaning towards it throwing an error (like "No schema found for class" or something)?

[stepanzabelin]

I would rather get joiful's error and resolve it in the development process but getJoiSchema function is needed

[codeandcats]

@stepanzabelin Okay that makes sense. 👍

@laurence-myers if you’re happy I’ll make the necessary changes tomorrow night (bedtime now) and follow up with a publish.

[codeandcats]

Okay, I've changed the default behaviour of the validator functions (validate, validateAsClass, validateArrayAsClass) so that they will error (with NoValidationSchemaForClassError) when trying to validate against a class that has no schema associated with it. This will be a breaking change and will trigger a major version bump when releasing.

I've also added a new convenience function hasSchema(Class): boolean

CC: @stepanzabelin.

Can you please re-review @laurence-myers?

[stepanzabelin]

Hi there. I am looking forward to a new release 🔥

[codeandcats]

@stepanzabelin Sorry for the hold up. I've just merged and published version 2.0.0. 😄

[stepanzabelin]

@codeandcats many thanks I've installed and tested. Everything is fine!