Serialize in request validation and authorize object when toJSON() matches to the format

Is your feature request related to a problem? Please describe. I would like to do 2 things :

• serialize String data to Object when I receive it from request
• deserialize object when i want to return the response and validate my response

I have two kinds of objects in my mind :

• Date objects
• Mongodb ObjectID

Describe the solution you’d like It could be great to allow developers to add some adapters that could be considered by express-openapi-validator on request and on response. For example, i could declare in my openapi components section :

  components: 
    schemas: 
      ObjectId:
        type: "string"
        pattern: "^[0-9a-fA-F]{24}$"
      Date:
        type: "string"
        format: "date"
      DateTime:
        type: "string"
        format: "date-time"

then i could configure my OpenAPIValidator with those adapters :

OpenApiValidator({
  apiSpec: './test/resources/openapi.yaml',
  validateRequests: true, // (default)
  validateResponses: true, // false by default
  formatAdapters : {
     '#/components/schemas/ObjectId' : {
        serialize : o => new ObjectID(o)
        deserialize : o => o.toJSON()
    },
    '#/components/schemas/Date' : {
        serialize : o => new Date(o)
        deserialize : o => o.toISOString().slice(0,10);
    },
    '#/components/schemas/DateTime' : {
        serialize : o => new Date(o)
        deserialize : o => o.toISOString();
    } 
  }
})

Describe alternatives you’ve considered I already tried to hack the formats.js by adding new formats and a “validate” description I also used in the past (2014-2015), a library, “tdegrunt/jsonschema” ,in which I added a hook to do this. I manage to do this but I need to parse twice the JSON body : once with jsonschema then once with express-openapi-validator.

Additional context I saw some issues related to this issue even if they are not explained the same way. I think this solution would be adaptable :

• https://github.com/cdimascio/express-openapi-validator/issues/246

[pilerou]

In my pull request, I tested it. It also worked for request parameters.

[cdimascio]

v4.10.0 resolves this issue for date-time and date formats. a custom serializer mechanism is still required for custom types e.g. MongoDb ObjectId

This issue must remain open as a solution is still needed for custom serializers to handle cases like ObjectId