operationResolver.md

fastify-openapi-glue

operationResolver

The easiest way to use fastify-openapi-glue is to use the serviceHandlers option.

However if you need more flexibility in mapping operationId's to methods then the operationResolver can be convenient.

You provide a function and that function returns the method that will handle the request.

An example of a simple resolver is:

const myObject = { getPetbyId: async () => { pet: "Doggie the dog" }};

function (operationId) {
  if (operationId in myObject) {
    return myObject[operationId];
  }
};

But you can make the logic as complex as you like.

In this example myObject[operationId] points to a function, but you can also point it to a full Fastify route definition, e.g.:

const myObject = { getPetbyId: {
    onSend: async (req, res) => {
      res.code(304);
      return null;
    },
    handler: async () => {
      return { pet: "Doggie the dog" };
    },
  };
}

In that case any properties returned by the operationResolver are added to the route configuration that the plugin already created itself, overriding any already existing properties.

The operationResolver will only be called during the creation of the Fastify configuration.