fluent-validator

Fluent validator that enables validation on multiple parameters at once.

Chained validation

Express paginated endpoint

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
});

Separating validation rules

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.

Result checking

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.

Simple shortcut

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
 

Simple validation

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

Configuration

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;
    }));
});

Validations

List of available validations.

Comparisons

• 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

Dates

• 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

Numbers

• 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

String

• 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

Other

• 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
• isNotNull(value) - checks if value !== null
• isUndefined(value) - checks if value === undefined
• isNotUndefined(value) - checks if value !== undefined
• isNullOrUndefined(value) - checks if value === undefined || value === null
• isNotNullOrUndefined(value) - checks if value !== undefined && value !== null
• isEmpty(value) - checks if value is defined and is a non empty array or non empty object or non empty string
• isNotEmpty(value) - negation of isEmpty

Custom validation

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