Lazy Validator

Validate your javascript object, and transform their values. Sometimes, you don't just want to validate an object, but you want to transform the object values in some way e.g to uppercase, lower case, remove all r's e.t.c before working with it.

Installation

    npm install lazy-validator

Usage

Import

    const { createValidator } = require("lazy-validator")

Type Validation

Create your validator

    const userLoginValidator = createValidator("username.string, password.string")

Get your object(s)

    const validLoginObject = { username: "UsErOne", passsword: "nice" }
    const invalidLoginObject = { username: 1, password: {} }

Apply the validator

    const validationResult1 = userLoginValidator.parse(validLoginObject)
    const validationResult2 = userLoginValidator.parse(invalidLoginObject)

    console.log(validationResult1)
    // Result
    { 
        error: false, 
        data: { 
            username: 'UsErOne', 
            password: 'nice' 
        } 
    }

    console.log(validationResult2)
    // Result
    {
      error: true,
      errors: [
        'Expected (string) for (username) instead got (number)',
        'Expected property called (password)'
      ]
    }

Type Validation + Transformation

Now if you wanted to transform the username to lowercase after you have validated that it is a string.

Create your validator

    const userLoginValidator = createValidator("username.string.lowercase, password.string")

Define what your transformation does

Note: In the future, predefined transformation for common usecases will be available

    // Your transformation function should return an object, the object could be in two forms
    // When there is an error during transformation
    // { error: true, error_string: "description of error" }
    // When everything went right
    // { error: false, data: transformedData }
    userLoginValidator.add("lowercase", value => {
       return { error: false, data: value.toLowerCase() }
    })

Get your object(s)

    const validLoginObject = { username: "UsErOne", passsword: "nice" }
    const invalidLoginObject = { username: 1, password: {} }

Apply the validator

    const validationResult1 = userLoginValidator.parse(validLoginObject)
    const validationResult2 = userLoginValidator.parse(invalidLoginObject)

    console.log(validationResult1)
    // Result
    { 
        error: false, 
        data: { username: 'userone', password: 'nice' } 
    }

    console.log(validationResult2)
    // Result
    {
      error: true,
      errors: [
        'Expected (string) for (username) instead got (number)',
        'Expected property called (password)'
      ]
    }

Author

Wisdom Ogwu (iammadab)