Validate.js with React Native wrapper

validate_wrapper.js

import validation from 'validation.js'

export default function validate(fieldName, value) {
  // Validate.js validates your values as an object
  // e.g. var form = {email: '[email protected]'}
  // Line 8-9 creates an object based on the field name and field value
  var formValues = {}
  formValues[fieldName] = value

  // Line 13-14 creates an temporary form with the validation fields
  // e.g. var formFields = {
  //                        email: {
  //                         presence: {
  //                          message: 'Email is blank'
  //                         }
  //                       }
  var formFields = {}
  formFields[fieldName] = validation[field]

  
  // The formValues and validated against the formFields
  // the variable result hold the error messages of the field
  const result = validatejs(formValues, formFields)

  // If there is an error message, return it!
  if (result) {
    // Return only the field error message if there are multiple
    return result[field][0]
  }

  return null
}

👍

I got the following error: Cannot set property 'tests' of undefined
Here is my code.

import validation from 'validation.js'

export default function validate(fieldName, value) {
var constraints = {
	email: {
		presence: {
			message: "Email is required"
		},
		email: {
			message: "Doesn't look like a valid email"
		}
	}
};

var formValues = {};
formValues[fieldName] = value;

var formFields = {};
formFields[fieldName] = constraints[fieldName];

const result = validation(formValues, formFields);

if (result) {
	return result[fieldName][0];
}

return null;
}

For those who face the issue as @Big-Silver mentioned:
There are two similar npm packages available: validation.js and validate.js, this similarity by name becomes a confusion.
This approach works only with validate.js, so make sure to install the correct one: npm install --save validate.js

#Actually, it is not an error, but it is only structure of the code. using that you have to make your own wrapper
I try to make that as under...

import validation from 'validate.js'

export default function validate(fieldName, value) {
    var constraints = {
	email: {
	    presence: true,
	    format: {
	        pattern: /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/,
	        message: 'Invalid email id',
	    }
	},
	password: {
	    presence: true,
	    length: {
	        minimum: 4,
	        message: 'Invalid Password',
	    }
	},
	confirmPassword: {
	    presence: true,
	    equality: 'password'
	},
	phoneNo: {
	    presence: true,
	    format: {
	        pattern: "^[0-9]{10}$",
	        message: 'Invalid phone number',
	    },
	},
    };

    var formValues = {}
    formValues[fieldName] = value

    var formFields = {}
    formFields[fieldName] = constraints[fieldName]


    const result = validation(formValues, formFields)

    if (result) {
	return result[fieldName][0]
    }
    return null
}

For some strange reasons the confirmPassword field always returns a validation error, please how can I solve this blocker