Validar

Don’t complicate your object schema validation.

Validate objects synchronously or asynchronously.

Install

npm install validar

Introduction

Validation runner doesn’t contain any validation tests, it is meant to be used with tried and tested validation libraries such as Validator.js or you can write your own tests very easily.

Usage

Given an object with the data:

const person ={
  name:'Adam'
  location:{
    country:'Canada',
    city:'Montreal099',
  }
}
// Note: fields on the testing object can be nested any number of levels.

And validation object like this:

const personValidators = {
  name: isAlpha,
  lastName: isAlpha,
  occupation: isAlpha.required(),
  location: {
    country: [isString, isValidCountry], //multiple validators
    city: isCityInValidCountry,
  },
}
// isAlpha, isString, isValidCoutry, isCityInValidCountry are validation tests (more on that later)

Let’s validate the person object

// this is the validation step
const result = validate(personValidators, person)

Let’s look at the result

person object will fail validation because:

• occupation field does not exist on person object and it is required to exist.
• location.city is not a valid city in Canada

Note: person object will not fail validation because it lacks lastName field. The reason is because that field is not marked as required on the validation object. Validation object and object under test don’t have to have matching structure ( unless you want to ).

The result:

result = {
    valid:false,
    errors:[errorObj1,errorObj2],
    struct:{
        name:{
            error:false,
            missing:false,
            value:'Adam',
            field:'name',
            path:'name'
        }
        occupation:{
            error:true,
            missing:true,
            value:null,
            field:'occupation',
            path:'occupation',
            message:'Field "occupation" not provided'
        }
        location:{
            country:{
                error:false,
                missing:false,
                value:'Canada',
                field:'country',
                path:'location.country'
            },
            city:{
                error:true,
                missing:false,
                value:'Montreal099'
                field:'city',
                path:'location.city',
                message:'Field "location.city" is not a valid city in Canada'
            }
        }
    }
}
// result.errors[0] = result.struct.occupation
// result.errors[1] = result.struct.location.city
// result.missing[0] = result.struct.occuption

• Errors are conveniently storred in the errors array on the result object.
• Missing fields are stored in the missing array on the result object.

runkit example

Asynchronous validation

Validation tests can be asynchronous (talk to the database etc..) in that case you just use the validateAsync function and handle the promise that is returned when all validation tests are done.

validateAsync(personValidators, person).then(result => {
  console.log(result)
})

asynchronous runkit example

Check out documentation for more information about:

• Exploring result structure
• Creating validation tests
• Asynchronous validation

Author

• Ivan Vlatković

License

This project is licensed under the MIT License - see the LICENSE file for details