Port Validation from JavaScript Implementation

[mttrbrts]

Feature Request 🛍️

To mirror the functional API for Concerto, we need to implement validation of a JSON object against a model definition.

Use Case

Validation is a key operation of a schema language, and is used to determine whether data is valid with respect to the model and the language specification.

Possible Solution

The existing (empty) AccordProject.Concerto namespace should have a public class added that contains a validate operation with the following signature:

    public void validate(String jsonObject, ObjectValidatorOptions options) {
        //...
    }

Note that this is not a binary operation, i.e. there is no true/false response depending on the outcome of validation. Instead, a validation of a valid object will return successfully and validation of an invalid object will throw an exception that contains details of why the validation failed.

Context

The reference implementation for this is in the JS version of Concerto.

• The public API signature, https://github.com/accordproject/concerto/blob/master/packages/concerto-core/lib/concerto.js#L51
• The Object Validator visitor, https://github.com/accordproject/concerto/blob/master/packages/concerto-core/lib/serializer/objectvalidator.js

It is critical that implementations of Concerto for different runtimes have the same semantics and very close signatures. Extensions to the language should be avoided until parity is achieved with the JS implementation. It is expected that the JS implementation will continue to be the reference implementation for some time.

Detailed Description

A proper implementation of validation will also require porting of the ModelManager and associated introspection Classes (see #4).

Existing unit tests, which should be ported

• Basic
• Complex (serialization implicitly includes validation),
• Functional API

Dates are specified according to the ISO 8601 standard. We adopt the DayJS library which supports the following formats This spec must be respected in the .NET port. All of the following are valid date formats in Concerto.

YYYY-MM-DDTHH:MM:SS.000+hh:mm
YYYY-MM-DDTHH:MM:SS.000+hhmm
YYYY-MM-DDTHH:MM:SS.000Z
YYYY-MM-DDTHH:MM:SS.000
YYYY-MM-DDTHH:MM:SS
YYYY-MM-DDTHH:MM:SSZ
YYYY-MM-DD
YYYY-MM
YYYYMMDD
YYYYMMDDTHHMMSS

Regular expressions use the ECMAScript flavour, any validation of Regular Expressions in field validators should be performed in ECMAScript compatibility mode.

Error messages and console logs must not include any values from the input data, e.g. accordproject/concerto#483