how to properly construct a Joi validation for a field returning a function

How to Properly Construct a Joi Validation for a Field Returning a Function

If you are using TypeScript and working with Joi, you might come across a scenario where you need to validate a field that returns a function. Constructing a proper Joi validation for this can be a bit tricky, but fear not! In this blog post, we will explore different solutions to tackle this problem.

Solution 1: Using the ‘function’ Method

The first solution involves using the function method provided by Joi. This method allows us to validate that a field is a function.

const Joi = require('joi');

const schema = Joi.object({
  myFunction: Joi.function().required()
});

const data = {
  myFunction: () => {
    // Your function code here
  }
};

const result = schema.validate(data);

console.log(result);

The code snippet above demonstrates how to construct a Joi validation schema for a field that returns a function. The Joi.function() method is used to validate that the myFunction field is indeed a function. The .required() method ensures that the field is not empty.

Solution 2: Using the ‘alternatives’ Method

Another solution is to use the alternatives method provided by Joi. This method allows us to specify multiple validation options and ensures that at least one of them is satisfied.

const Joi = require('joi');

const schema = Joi.object({
  myFunction: Joi.alternatives().try(Joi.function(), Joi.string()).required()
});

const data = {
  myFunction: () => {
    // Your function code here
  }
};

const result = schema.validate(data);

console.log(result);

In the code snippet above, we use the Joi.alternatives() method to specify multiple validation options for the myFunction field. We use Joi.function() to validate that the field is a function and Joi.string() to validate that it is a string. The .try() method ensures that at least one of the validation options is satisfied.

Conclusion

Constructing a Joi validation for a field returning a function in TypeScript can be achieved using either the function method or the alternatives method. Both methods provide a way to validate the field and ensure that it meets the required criteria.

Remember to choose the solution that best suits your specific use case. Happy coding!