Fluent validator that enables validation on multiple parameters at once.

Example with express paginated endpoint. Both query parameters (page and size) must be positive integers or empty values.

var validator = require('fluent-validator');

app.get('/users', function() {
	validator()
		.validate(req.query.page).param('page').isInt().and.isPositive().or.isEmpty()
		.validate(req.query.size).param('size').isInt().and.isPositive().or.isEmpty()
		.throwOnError();

	// query params are valid
});

OR Separator

// Example: chain1.or.chain2
validator().validate(value).isInt().or.isEmpty();

• if value passes validation chain1 than chain2 is omitted and validation passes successfully.
• if value does not pass validation chain1 than chain2 is checked.
• if value does not any of validation chains then errors are produced from chain1.

AND Separator

// Example: chain1.and.chain2
validator().validate(value).isInt().and.isPositive().isDivisibleBy(2);

• if value passes validation chain1 than chain2 is checked as well.
• if value does not pass validation chain1 than chain2 is omitted and errors are produced from chain1.

You can react on validation result in multiple ways:

var validation = validator()
	.validate(req.query.page).isInt().and.isPositive().or.isEmpty()
	.validate(req.query.size).isInt().and.isPositive().or.isEmpty();

validation.getErrors(); // Returns array of validation errors
validation.hasErrors(); // Returns true if there are validation errors
validation.check(); // Returns true if there are no validation errors
validation.throwOnError(); // Throws error if there are validation errors.

You can shorten validation chain:

var validation1 = validator().validate(req.query.page).isInt().and.isPositive().or.isEmpty();
var validation2 = validator(req.query.page).isInt().and.isPositive().or.isEmpty();

// validation2 is just a shorter version of validation1

Validation without chaining.

var validator = require('fluent-validator');

// isPositive: just executes checks if input > 0
validator.isPositive(1);		// true
validator.isPositive(-1);		// false
validator.isPositive("1");		// true
validator.isPositive("-1");		// false
validator.isPositive(0.1);		// true
validator.isPositive(-0.1);		// false
validator.isPositive("0.1");	// true
validator.isPositive("-0.1");	// false
validator.isPositive({});		// false
validator.isPositive([]);		// false

Customizing the validator.

var validator = require('fluent-validator');

// Adding custom validations
validator.add('isEqualTo123', 'Value is not equal to 123', function(value) {
	return value === 123;
});
validator.add('isDivisibleBy', 'Expected ${0} to be divisible by ${1}', function(value, divisibleBy) {
	return value % divisibleBy === 0;
});

// Adding custom error thrower used in validation.throwOnError()
validator.throwError = function(errors) {
	new Error('Validation error. ' + errors.map(function(error) {
		return error.message;
	}));
});

List of available validations.

• isIn(value, arr) - check if value is in array
• isPositive(value) - check if value > 0
• isNegative(value) - check if value < 0
• isNonNegative(value) - check if value >= 0
• isNonPositive(value) - check if value <= 0
• isLower(value, bound) - check if value < bound
• isLowerOrEql(value, bound) - check if value <= bound
• isGreater(value, bound) - check if value > bound
• isGreaterOrEql(value, bound) - check if value >= bound
• isInRange(value, min, max) - check if value > min && value < max
• isInRangeOrEql(value, min, max) - check if value >= min && value <= max

• isDate(value) - check if value is of type Date or can be parsed with Date.parse()
• isAfter(value, min) - check if value > min
• isAfterOrEql(value, min) - check if value >= min
• isBefore(value, max) - check if value < max
• isBeforeOrEql(value, max) - check if value <= max

• isInt(value) - check if value is an numerical or textual representation of an integer
• isFloat(value) - check if value is an numerical or textual representation of a float
• isNumber(value) - check if value is an numerical or textual representation of a number
• isHexadecimal(value) - check if value is an numerical or textual representation of a hexadecimal number
• isDivisibleBy(value, x) - check if value is an numerical or textual representation of a number that is divisible by x

• contains(value, text) (alias: isIn) - check if value is in text
• isLength(value, length) - check if value is of given length
• matches(value, regexp) - check if regexp matches value
• isAlpha(value) - check if value is contains only [a-zA-Z]
• isNumeric(value) - check if value is contains only [0-9]
• isAlphanumeric(value) - check if value is contains only [a-zA-Z0-9]
• isLowercase(value) - check if value is lowercased
• isUppercase(value) - check if value is uppercased

• isAscii(value) - check if value is contains only ASCII characters
• isEmail(value) - email RegExp validation
• isURL(value) - URL RegExp validation
• isIP(value) - IP RegExp validation
• isBase64(value) - Base64 RegExp validation
• isHexColor(value) - Base64 RegExp validation
• isUUID(value) - UUID RegExp validation
• isJSON(value) - UUID RegExp validation
• isCreditCard(value) - CreditCard RegExp validation
• isISBN(value) - ISBN RegExp validation
• isMongoObjectId(value) - MongoObjectId RegExp validation
• isNull(value) - checks if value === null
• isUndefined(value) - checks if value === undefined
• isNullOrUndefined(value) - checks if value === undefined || value === null
• isEmpty(value) - checks if value is defined or is a non empty array or non epmty object

• passes(value, check, message) - checks if value passes check function. In case of validation error message parameter is used.