express-req-validate

Mongoose-inspired req.query and req.body validator for express/connect servers.

Installation

npm install --save express-req-validate

Load the validator middleware after the body parser.

var bodyParser = require('body-parser');
var queryParser = require('express-query-int');
var reqValidate = require('express-req-validate');
 
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(queryParser());
app.use(reqValidate());

Validating `req.body`

By default the module will only attempt to validate req.query. To validate req.body:

req.validate(req.body, {
  // your model here...
});

To validate both req.query and req.body:

req.validate([req.query, req.body], {
  // your model here...
});

Model

model.type

Checks if request parameter is created by the specified constructor.

req.validate({
  a: {
    type: String
  }
});
// ?a=b     => true
// ?a[0]=b  => false

Note: By default, numbers in query parameters will be strings. To use { type: Number } you will need a parser such as express-query-int.

model.required

Checks if request parameter is present.

req.validate({
  a: {
    required: true
  }
});
// ?a    => true
// ?a=0  => true
// ?a=b  => true

model.min

If parameter is a Number, checks that it is greater than or equal to min.

req.validate({
  a: {
    type: Number,
    min: 10
  }
});
// ?a=10  => true
// ?a=11  => true
// ?a=9   => false

If parameter is a String, checks that the string is longer or equal length to min.

req.validate({
  a: {
    type: String,
    min: 3
  }
});
// ?a=abc   => true
// ?a=abcd  => true
// ?a=ab    => false

If parameter is an Array, checks that the array.length is greater than or equal to min.

req.validate({
  a: {
    type: Array,
    min: 2
  }
});
// ?a[0]=b&a[1]=c         => true
// ?a[0]=b&a[1]=c&a[2]=d  => true
// ?a[0]=b                => false

If no type is specified, validator will do its best to guess. To ensure that you get the expected result, it is recommended to provide a type.

model.max

If parameter is a Number, checks that it is less than or equal to max.

req.validate({
  a: {
    type: Number,
    max: 10
  }
});
// ?a=10  => true
// ?a=9   => true
// ?a=11  => false

If parameter is a String, checks that the string is shorter or equal length to max.

req.validate({
  a: {
    type: String,
    max: 3
  }
});
// ?a=abc   => true
// ?a=ab    => true
// ?a=abcd  => false

If parameter is an Array, checks that the array.length is less than or equal to max.

req.validate({
  a: {
    type: Array,
    max: 2
  }
});
// ?a[0]=b&a[1]=c         => true
// ?a[0]=b                => true
// ?a[0]=b&a[1]=c&a[2]=d  => false

If no type is specified, validator will do its best to guess. To ensure that you get the expected result, it is recommended to provide a type.

model.each

Checks that each value of the Object/Array meets condition. Return:

true - passes validation
false - fails validation
new Error('msg') - fails validation with custom message

req.validate({
  a: {
    each: function(value) {
      return value > 3;
    }
  }
});
// ?a[0]=b&a[4]=c  => true
// ?a[0]=b&a[2]=c  => false

model.validator

Checks that value passes custom function validation. Return:

true - passes validation
false - fails validation
new Error('msg') - fails validation with custom message

req.validate({
  a: {
    validate: function(value) {
      return new Error('You shall not pass!');
    }
  }
});
// ?a  => false

Note: You could use a custom validation library like Validator.js for each and validate.

var validator = require('validator');
req.validate({
  a: {
    validate: validator.isCreditCard
  }
});
// ?a  => false

Errors

The validator will not throw an error, instead it will set req.validateError to an error object. If there are no validation errors, req.validateError will be null.

req.validate(...)
 
if (req.validateError) {
  return yourOwnErrorHandler(res, req.validateError);
}

Custom Error Format

You can set a custom error format when initializing the module. See lib/error.js for the default constructor.

function ErrorGenerator(message, options) {
  this.message = message;
}
 
ErrorGenerator.prototype = Error.prototype;
 
app.use(reqValidate({
  ErrorGenerator: ErrorGenerator
}))