Validation

Validation definitions are used for:

• preparing the API documentation
• validation of parameters
• constructing responses

Validations can be automatically derived from types defined for the handler parameters and result, or can be manually specified.

Automatic

For automatic definitions the following is required:

• Put a file named ~.schema.ts in the folder where the handlers are defined. This file is automatically updated when its date is older than another file within the folder, where a type named Handler is defined.

• Define the type Handler for each handler that will use automatic validations. Here is an example how it must be defined:

  
  import {IMeta, handler} from '@feasibleone/blong';
  
  /** @description "Description of the handler" */
  type Handler = ({
      /** @description "Description of param property" */
      paramProperty: string
  ) => Promise<{
      /** @description "Description of result property" */
      resultProperty: number;
  }>;
  
  export default handler(() =>
    async function subjectObjectPredicate(
        params: Parameters<Handler>[0],
        $meta: IMeta
    ): ReturnType<Handler> {
        // implementation
    }
  );

Manual

To define validations manually, put them in a subfolder of the gateway layer and use the validation function from the framework. The framework will provide access to the TypeBox API via the lib.type property.

Here is an example:

// realmname/gateway/subject/subjectObjectPredicate.ts
import {validation} from '@feasibleone/blong';

export default validation(({lib: {type}}) =>
    function subjectObjectPredicate() {
        return {
            // at a minimum, define the types of params and result
            params: type.Any(),
            result: type.Any(),
            // some optional overrides
            auth: false,                // turn off authentication
            description: 'description', // set the description for docs
            method: 'GET',              // the default is POST
            path: '/some/path',         // change the path
        };
    }
);