Generic middleware validator

Hello, I'm trying to write a middleware in my app that handles validating the incoming request body. It currently looks like this

export function validateBody<T extends Type>(
  validator: T
): MiddlewareObj<ValidatedBody<T["infer"]>> {
  return {
    before: async ({ event }: Request) => {
      if (!event.body) return { statusCode: 400 };
      const result = validator(event.body);
      if (result instanceof type.errors) {
        throw new ClientError(result.summary);
      }
      event.body = result;
    },
  };
}

export function validateBody<T extends Type>(
  validator: T
): MiddlewareObj<ValidatedBody<T["infer"]>> {
  return {
    before: async ({ event }: Request) => {
      if (!event.body) return { statusCode: 400 };
      const result = validator(event.body);
      if (result instanceof type.errors) {
        throw new ClientError(result.summary);
      }
      event.body = result;
    },
  };
}

The return type means that in my handler

body

body

comes through with the correct type definition given by the validator, e.g.

const schema = type({name:"string"}}
const handleRequest = middy()
  .use(validateBody(schema))
  .handler(async ({ body }) => {
    // body.name === string!
  });

const schema = type({name:"string"}}
const handleRequest = middy()
  .use(validateBody(schema))
  .handler(async ({ body }) => {
    // body.name === string!
  });

This has worked nicely so far, but unfortunately with larger schemas I'm getting a

Type instantiation is excessively deep and possibly infinite

Type instantiation is excessively deep and possibly infinite

error when calling

validateBody

validateBody

.

I've read answers to similar questions questionsFunction which receives a arktype's 'type' and questionsProperty 'describe' does not exist on type 'instantiateType<inferTupleExpression<...>, {}>', and tried out some of the suggestions, but I haven't been able to come up with a solution so far.

Is there any way to get this working as expected, or is it not possible with the current limitations of Typescript? Am I safer just casting

body

body

in the

handler

handler

to the expected type (since at that point it has passed validation and I know that it conforms to the expected type)?

Any help or suggestions would be greatly appreciated, thanks!

Generic middleware validator

Hello, I'm trying to write a middleware in my app that handles validating the incoming request body. It currently looks like this

export function validateBody<T extends Type>(
  validator: T
): MiddlewareObj<ValidatedBody<T["infer"]>> {
  return {
    before: async ({ event }: Request) => {
      if (!event.body) return { statusCode: 400 };
      const result = validator(event.body);
      if (result instanceof type.errors) {
        throw new ClientError(result.summary);
      }
      event.body = result;
    },
  };
}

export function validateBody<T extends Type>(
  validator: T
): MiddlewareObj<ValidatedBody<T["infer"]>> {
  return {
    before: async ({ event }: Request) => {
      if (!event.body) return { statusCode: 400 };
      const result = validator(event.body);
      if (result instanceof type.errors) {
        throw new ClientError(result.summary);
      }
      event.body = result;
    },
  };
}

The return type means that in my handler

body

body

comes through with the correct type definition given by the validator, e.g.

const schema = type({name:"string"}}
const handleRequest = middy()
  .use(validateBody(schema))
  .handler(async ({ body }) => {
    // body.name === string!
  });

const schema = type({name:"string"}}
const handleRequest = middy()
  .use(validateBody(schema))
  .handler(async ({ body }) => {
    // body.name === string!
  });

This has worked nicely so far, but unfortunately with larger schemas I'm getting a

Type instantiation is excessively deep and possibly infinite

Type instantiation is excessively deep and possibly infinite

error when calling

validateBody

validateBody

body

body

in the

handler

handler

to the expected type (since at that point it has passed validation and I know that it conforms to the expected type)?

Any help or suggestions would be greatly appreciated, thanks!

Generic middleware validator

Similar Threads

Generic middleware validator

Similar Threads

Similar Threads

Similar Threads