How to use Custom Scalars with the graphql-mesh?

[nemonemi]

It is not clear to me how to achieve it from the documentation on the https://www.graphql-scalars.dev/docs/quick-start.

How can one integrate custom scalars with the grahql-mesh?

[ardatan]

Mesh uses most of the scalars from there already.
Could you explain a bit more of your use case? What do you want to do?

[nemonemi]

That, I didn't know.
I wanted to add support for more scalars by utilizing the graphql-scalars library.
Is there a list of custom scalars that are supported out of the box?

[ardatan]

It depends on which handler you are using. For example, MySQL Handler uses those;
https://github.com/Urigo/graphql-mesh/blob/master/packages/handlers/mysql/src/index.ts#L23
JSON Schema handler;
https://github.com/Urigo/graphql-mesh/blob/master/packages/handlers/json-schema/src/json-schema-visitor.ts#L296
OpenAPI handler uses the similar ones with JSON Schema handler and gRPC so on.

[nemonemi]

I'm using the Graphql handlers.

I'm actually not sure how this is supposed to work, however, the schema defines a property to be of a type DateTime, however, I am able to provide a regular string.
e.g.

{
  valid_from: DateTime
}

# Scalars
scalar DateTime

I expect that Graphiql complains and doesn't allow any other format but DateTime for that property.