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node.jsvalidationuser-inputjsonschema

Should I validate input in API or BL layer?

I have a node.js application with an API, BL and DAL layers and I want to validate user input.

Currently I'm doing the validation at the beginning of BL functions so it doubles as a user input validator and an inner application validators (calls from other classes)

I'm worried it's not good practice as the validation may happen multiple times on a single API call for some functions (e.g a function that accepts userId and then sends the userId to other functions, validating the same value multiple times)

Solution

  • You should validate data when it comes from request to your routes using middleware:

    router
  .get('/', validators.users.index, actions.users.index)

    If you wish I can share the rest of the code of validation with Joi.