@telegraph-engineering/node-validator

TMG Node Validator

Build Status

Install

    npm install @telegraph-engineering/node-validator --save

Description

TMG node validator is a library for validating that any passed object conforms to the spec passed to it.

Getting started

Once you have installed the pacakge, it can be required, which will return a function that accepts two paramters. The first being the object you wish to test, and the second is the config that the object should be validated against.

Example Checking that a parameter is defined and has type string.

const Validator = require('@telegraph-engineering/node-validator');
const spec = {
    name: {
	    required: true,
	    type: 'string'
	}
};
const param = {} //your object to test;

const errors = Validator(param, spec);
if (errors && errors.length > 0) {
	console.error("Validation failed");
	console.log(errors.join(' & '));
	return;
}

//else do your other logic

Spec options

Name	Type	Default	Description
children	{object}		all specs for children should be passed in the child param
required	{boolean}	false	wether or not the paramter must be present
type	{string}		The data type that the field must be, equivelant of typeof param
requiredIf	{string}		This field is used to specify that this field is required if the passed key is undefined
validation	{function}		A custom validator function, which will be called with the value of the parameter under test, if the function returns anything other than undefined it will be treated as a failure
validValues	{array}		An array of possible values for this parameter

children

If a passed object has children that you wish to validate, you can pass the specs for the children as children parameter

const spec = {
    param1: {
	    children: {
		    param2: {
			    required: true
		    }
	    }
    }
};
Validate({param1: {param2: undefined}}) //fail
Validate({param1: {param2: true}}) //pass

required

This field defines if a field is required

const spec = {
    param1: {
	    required: true
    }
};
Validate({param1: undefined}) //fail
Validate({param1: true}) //pass

type

This field defines what type of fata the field must contain, if it is defined

const spec = {
    param1: {
	    type: 'string'
    }
};
Validate({param1: 1234}) //fail
Validate({param1: 'String'}) //pass

requiredIf

This field allows you to specify that this field is required, if another field is undefined

const spec = {
    param1: {
	    requiredIf: 'param2'
    },
    param2: {
	    type: 'string'
    }
};
Validate({param1: undefined, param2: undefined}) //fail
Validate({param1: undefined, param2: 'String 2'}) //pass
Validate({param1: 1234}) //pass
Validate({param1: 'String', param2: 'String 2'}) //pass

validation

Allows the passing of a custom function to validate values

const spec = {
    param1: {
	    validation: (val) => {
		    if (val.indexOf('invalid') < -1) {
			    return "Should not contain invalid";
		    }
	    }
    }
};
Validate({param1: 'this string is invalid'}) //fail
Validate({param1: 'this string is valid'}) //pass

validValues

Allows the passing of a list of values that the paramter must match one of

const spec = {
    param1: {
	    validValues: ['valid', 27]
    }
};
Validate({param1: 'this string is invalid'}) //fail
Validate({param1: 27}) //pass
Validate({param1: 'valid'}) //pass

Limitations

• The tool cannot currently validate the values of arrays

The future

• Support for arrays
• Support for callback/ promise for custom validation