isFoo Functions should return an error message about which fields are missing or of wrong type

[juliandm]

currently the generated functions just return a Boolean value. However in cases where ts-auto-guard is used for user feedback, a simple yes or no is not sufficient. A path to the faulty attributes would be better

{
 "isWellDefined": true
}

success response

{
 "isWellDefined": false,
 "faultyPaths": [".first.second.third", ".second.foo.bar"]
}

faulty example, could be even more specific about, which type was expected etc..

[juliandm]

Although i like the concept of ts-auto-guard i solved it now by combining two other more standardised open source projects:

1. generate a json schema of your ts types with https://github.com/vega/ts-json-schema-generator
2. put this schema into ajv schema validator https://github.com/ajv-validator/ajv

works beautifully and also template literals and other advanced features of ts are worked on.

[rhys-vdw]

@juliandm you can use debug mode to information about the first field that failed, however it is not intended for production.

This library is not a validation library, it generates type guards, which conventionally do not give more information other than is or is not a type.

That said when I first started working on this I did intend to create an option to generate validators, which is why it needs type-guard in the comment annotation (so that I could later add type-validator etc.) But if you're looking for runtime type validator you're better off using a library that explicitly has that as one of its goals.

I'll leave this issue open for now in case there's any more discussion.