Second generation object or request validator for node.js
_better-validator_ is my second generation object or request validator for node.js.
NEW for my latest validator that is cleaner and tidier with even better type support and data sanitization, check out validata and validata-koa.
The aim of this validator is to
* be simple to use
support a number of usage patterns including a fluent interface*
* support re-use of validator parts
* support deep object and array validation
* be able to customise the output structure
* be able to customise failure messages
* support i18n
* use the well known validator library for string validation
* be easily used with both express.js, koa.js and koa@next
* written in and works with typescript (>= v2.0.0, see Section on Breaking Changes below)
Javascript
``javascript`
const Validator = require('better-validator');
const validator = new Validator(options);
Typescript
`typescript`
import Validator from 'better-validator';
const validator = Validator.create(options); // can also use new Validator(), but this has better type support due to trying to keep as much backwards compatibility as possible with v1.x
Options
- failureFormatter function or formatter class that will be used to format
each failure that is created. See below (quite a long way below, somewhat near the bottom).
Simple validation
`javascript
const validator = new Validator();
validator(123).isNumber();
const errors = validator.run(); // => []
`
`javascript
const validator = new Validator();
validator('not number').isNumber();
const errors = validator.run(); // => [{path: [], value: 'not number', failed: 'isNumber'}]
`
Validate multiple objects at once:
`javascript
const validator = new Validator();
const query = {};
const body = null;
validator(query).display('query').required();
validator(body).display('body').required();
const errors = validator.run(); // => [{path: ['body'], value: null, failed: 'required'}]
`
Validate children of an object:
`javascript
const validator = new Validator();
const query = {count: 5, hint: 32};
validator(query).required().isObject((obj) => {
obj('count').required().isNumber().integer(); // pass
obj('hint').isString(); // fail
});
const errors = validator.run(); // => [{path: ['hint'], value: 32, failed: 'isString'}]
`
Validate children of an array:
`javascript
const validator = new Validator();
const array = [{count: 5, hint: 32}];
validator(array).required().isObjectArray((child) => {
child('count').required().isNumber().integer(); // pass
child('hint').isString(); // fail
});
const errors = validator.run(); // => [{path: [0, 'hint'], value: 32, failed: 'isString'}]
`
`javascript
const validator = new Validator();
const array = [1, 2, 3.2, 'test'];
validator(array).required().isArray((item) => {
item.isNumber().required().integer();
});
const errors = validator.run(); // => [{path: [2], value: 3.2, test: 'integer'}, {path: [3], value: 'test', test: 'isNumber'}]
`
Re-usable validation parts:
`javascript
const validator = new Validator();
const rule = (item) => {
item.isNumber().integer().isPositive();
};
const errors = validator(123, rule); // => []
`
`javascript
const validator = new Validator();
const query = {count: 5, hint: '32'};
const rule = (item) => item.isNumber().integer().isPositive();
validator(query).required().isObject((child) => {
child('count').check(rule).lte(10); // pass
child('hint').check(rule); // fail
});
const errors = validator.run(); // => [{path: ['hint'], value: '32', failed: 'isNumber'}]
`
Using with express.js
`javascript
const WrapperFormatter = Validator.format.response.WrapperFormatter;
const FailureFormatter = Validator.format.failure.FailureFormatter;
const check = Validator.koaMiddleware({
responseFormatter: new WrapperFormatter(),
failureFormatter: new FailureFormatter()
});
const queryRule = (query) => {
query('email').isEmail();
query('date').isISO8601();
};
const bodyRule = (body) => {
body('count').required().isNumber().integer();
body('hint').isString();
body().strict(); // make sure there aren't any expected properties in the body
};
app.post('/', check.query(queryRule), check.body(bodyRule), function(req, res) {
// ...
});
`
Using with koa.js
`javascript
const WrapperFormatter = Validator.format.response.WrapperFormatter;
const FailureFormatter = Validator.format.failure.FailureFormatter;
const check = Validator.koaMiddleware({
responseFormatter: new WrapperFormatter(),
failureFormatter: new FailureFormatter()
});
const queryRule = (query) => {
query('email').isEmail();
query('date').isISO8601();
};
const bodyRule = (body) => {
body('count').required().isNumber().integer();
body('hint').isString();
body().strict(); // make sure there aren't any expected properties in the body
};
route.post('/', check.query(queryRule), check.body(bodyRule), otherFunction);
`
Using with koa@next (and koa-router@7) and typescript
`javascript
import Validator from 'better-validator';
const WrapperFormatter = Validator.format.response.WrapperFormatter;
const FailureFormatter = Validator.format.failure.FailureFormatter;
const check = Validator.koa2Middleware({
responseFormatter: new WrapperFormatter(),
failureFormatter: new FailureFormatter()
});
const queryRule = (query) => {
query('email').isEmail();
query('date').isISO8601();
};
const paramsRule = (params) => {
params('id').required();
};
route.get('/:id/', check.query(queryRule), check.params(paramsRule), otherFunction);
`
If the body content does not pass the given validation check, the validator will return.
`
400 Bad Request
{
"type": "ValidationError"
"failures": [
{
"parameter": "children[0].prop",
"value": "zxzx",
"failed": "required"
}
]
}
`
- isArrayOf changed to isObjectArray
- access to formatters changed to and similar
$ npm install -S better-validator
Following are the build-in validators. You may also use your own, see section below.
The various type validators will accept the specified type or null or undefined. To modify the check to not acceptnull or undefined, add the required() constraint.
`javascript`
validator(value).required();
`javascript`
validator(value).isString().required();
`javascript`
validator(value).required().isString();
A variation on the above will also allow a null value as well.
`javascript`
validator(value).requiredWithNull();
`javascript`
validator(value).requiredWithNull().isString();
`javascript`
validator(value).isEqual(7);
`javascript`
validator(value).notEqual('test');
#### Conditional checks
`javascript`
validator(value).if((value) => value < 7, (conditional) => {
conditional.isEqual(4);
});
Used to validate that the value under test is an object, and to check it's properties.
`javascript`
validator(value).isObject((obj) => {
obj('count').required().isNumber().integer();
obj('hint').isString();
});
To ensure that the object has only the expected properties, the strict() constraint is added.
`javascript`
validator(value).isObject((obj) => {
obj('count').required().isNumber().integer();
obj('hint').isString();
}).strict();
Makes sure the value is of type string.
`javascript`
validator(value).isString();
`javascript`
validator(value).isString().isEmail();
Returns true if the value is present in the list.
Very convenient to validate if a enum contains the given value
`javascript`
validator(value).isIncludedInArray(['define1','define2']);
`javascript`
validator(value).required().isEmail().isIncludedInArray(['define1','define2']);
#### isString Checks
Checks from the library validator are included. Please see the link for more details.
All checks that start with is are mounted into the isString() module along with their inverse not
* isAfter(date), notAfter(date)
* , notAlpha(locale)
* , notAlphanumeric(locale)
* , notAscii()
* , notBase64()
* , notBefore(date)
* , notBoolean()
* , notByteLength(options)
* , notCreditCard()
* , notCurrency(options)
* , notDataURI()
* , notDate()
* , notDecimal()
* , notDivisibleBy(number)
* , notEmail(options)
* , notEmpty()
* , notFQDN(options)
* , notFloat(options)
* , notFullWidth()
* , notHalfWidth()
* , notHexColor()
* , notHexadecimal()
* , notIP(version)
* , notISBN(version)
* , notISSN(options)
* , notISIN()
* , notISO8601()
* , notIn(values)
* , notInt(options)
* , notJSON()
* , notLength(options)
* , notLowercase()
* , notMACAddress()
* , notMD5()
* , notMobilePhone(locale)
* , notMongoId()
* , notMultibyte()
* , notNumeric()
* , notSurrogatePair()
* , notURL(options)
* , notUUID(version)
* , notUppercase()
* , notVariableWidth()
* , notWhitelisted(chars)
Also regular expression checks can be performed with isMatch(regex), notMatch(regex), length(expected) and lengthInRange(lower, upper)
Like all other constraints, these amy be chained together:
`javascript`
validator(value).isAlphanumeric().isLowercase();
Makes sure the value is a boolean.
`javascript`
validator(value).isBoolean();
`javascript`
validator(value).isBoolean().isEqual(true);
Makes sure the value is a number.
`javascript`
validator(value).isNumber();
`javascript`
validator(value).isNumber().integer();
#### isNumber Checks
* integer()
* , notInRange(lower, upper)
*
*
*
*
* , notPositive()
* , notNegative()
* , notZero()
Makes sure that the item is of type array, and validates the items. Also can specify minimum and maximum length of the array.
`javascript`
validator(value).isObjectArray((item) => {
item('foo').isString();
item('bar').isString().required();
item().strict();
}).length(2);
`javascript`
validator(value).isObjectArray((item) => {
// ...
}).lengthInRange(4, 8); // 4 to 8 inclusive
`javascript`
validator(value).isObjectArray((item) => {
// ...
}).lengthInRange(undefined, 8); // less than or equal to 8
`javascript`
validator(value).isObjectArray((item) => {
// ...
}).lengthInRange(1); // one or more
Combination of isObjectArray and isObject.
If the item is of type array, it validates all child items.
If the item is of type Object it will validate the item as a child of the array
`javascript
const array = [{foo: ''}];
const object = {foo: ''};
validator(value).isArrayOrObject((item) => {
item('foo').isString();
})
`
`javascript
const array = [1, 2, 3.2, 'test'];
validator(array).required().isArray((item) => {
item.isNumber().required().integer();
});
const errors = validator.run(); // => [{path: [2], value: 3.2, test: 'integer'}, {path: [3], value: 'test', test: 'isNumber'}]
`
#### express.js
`
npm install -S i18n
Set up i18n as per normal
`javascript
const WrapperFormatter = Validator.format.response.WrapperFormatter;
const FailureFormatter = Validator.format.failure.FailureFormatter;
const I18nExpressFormatter = Validator.format.message.I18nExpressFormatter;
const check = Validator.koaMiddleware({
responseFormatter: new WrapperFormatter(),
failureFormatter: new FailureFormatter(),
translationFormatter: new I18nExpressFormatter()
});
const queryRule = (query) => {
query('email').isEmail();
query('date').isISO8601();
};
const bodyRule = (body) => {
body('count').required().isNumber().integer();
body('hint').isString();
body().strict(); // make sure there aren't any expected properties in the body
};
app.post('/', check.query(queryRule), check.body(bodyRule), function(req, res) {
// ...
});
`
#### koa.js and koa@next
`
npm install -S koa-i18n koa-locale
Set up koa-i18n and koa-locale as per normal
`javascript
import Validator from 'better-validator';
const WrapperFormatter = Validator.format.response.WrapperFormatter;
const FailureFormatter = Validator.format.failure.FailureFormatter;
const I18nExpressFormatter = Validator.format.message.I18nKoaFormatter;
const check = Validator.koa2Middleware({
responseFormatter: new WrapperFormatter(),
failureFormatter: new FailureFormatter(),
translationFormatter: new I18nKoaFormatter()
});
const queryRule = (query) => {
query('email').isEmail();
query('date').isISO8601();
};
const paramsRule = (params) => {
params('id').required();
};
route.get('/:id/', check.query(queryRule), check.params(paramsRule), otherFunction);
`
A failure formatter can be provided in the options for a validator. This is responsible for
a raw failure object and re-formatting it to match desired outcome. There is one failure
formatter provided
#### Validator.format.failure.FailureFormatter
Example below of a provided failure formatter, showing its default option values.
`javascript
const FailureFormatter = Validator.format.failure.FailureFormatter;
const PathFormatter = Validator.format.path.PathFormatter;
const formatterOptions = {
pathElement: 'parameter',
pathFormatter: new PathFormatter({
initialSeparator: '',
separator: '.'
})
};
const validatorOptions = new FailureFormatter(formatterOptions);
const validator = new Validator(validatorOptions);
// will change the path in each failure to parameter and format it as an`
// string rather than an array
The middleware (express, koa and koa@next) also take a response formatter. This takes in the
array of failures and determines how is is presented in the response.
#### Validator.format.response.WrapperFormatter
This wraps the failures in an object, based on the given staticTemplate.
`javascript
const WrapperFormatter = Validator.format.response.WrapperFormatter;
const FailureFormatter = Validator.format.failure.FailureFormatter;
const wrapperOptions = {
staticTemplate: {
type: 'ValidationError'
},
wrapperElement: 'failures'
};
const check = Validator.koa2Middleware({
responseFormatter: new WrapperFormatter(),
failureFormatter: new FailureFormatter()
});
// will wrap the failures like {"type": "ValidationError", "failures": [...]}
`
Custom formatters may be used in place of any of the provided ones.
A customer formatter is either a function or an object that has a format method.
`javascript`
function myFormatter(failure) {
return {
message: 'work something out here'
};
}
`javascript``
class MyFormatter {
format(failure) {
return {
message: 'work something out here'
};
}
}
const formatter = new MyFormatter();
(The MIT License)
Copyright (c) 2013
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
'Software'), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.