Contracts

Define contracts for functions and express handlers to validate and filter parameters. This library bundles the Json Schema Validator package with customizable format validation and filter support. It includes some nice filters and formats from the node-validator library.

Defining Schemas

var contracts = require('contracts')
  , f = contracts.filters;

var addSchema = {
  type: 'array',
  items: {
    type: 'number',
    filter: f.toFloat()
  }
};

var userSchema = {
  type: 'object',
  additionalProperties: false,
  filters: f.cleanObject(),
  properties: {
    email: { type: 'string', required: true, format: 'email' },
    password: { type: 'string', required: true, minLength: 6 },
    age: { type: 'integer', required: true, filter: f.toInt() }
  }
};

Validating to a schema

var report = contracts.validate([5, '13', 8], addSchema);
report.errors;   // []
report.instance; // [5, 13, 8]

Transforming data using a schema

var new_obj = contracts.transform({email: 'foo@bar.com', password: 'foobar', age: '15', DANGEROUS: '...'}, userSchema);
new_obj; // {email: 'foo@bar.com', password: 'foobar', age: 15}

Wrapping functions for validation and data-fixing

var add = contracts.wrap(function() {
  var args = [].slice.call(arguments)
    , sum = args.reduce(function(a,b) { return a + b; }, 0);
  return sum;
}, addSchema);

add('5', '19.5', 3); // 27.5
add(1, {});          // throw ValidationError()

Validating post data in express with a view middleware

var app = express.createServer();
app.use express.bodyParser();

app.post('/users', contracts.view(userSchema), function(req, res) {
    req.body; // {email: 'foo@bar.com', password: 'foobar', age: '15', DANGEROUS: '...'}
    req.data; // {email: 'foo@bar.com', password: 'foobar', age: 15}
});

Built-in filters

• cleanObject
• cleanArray
• removeEmpty

From node-validator:

• xss
• entityDecode
• entityEncode
• ltrim
• rtrim
• trim
• ifNull
• toFloat
• toInt
• toBoolean
• toBooleanStrict

Built-in format validators

From node-validator:

• email
• url
• ip
• int
• decimal
• float
• uuid

Custom filters

var schema = {
  type: 'string',
  filter: function(str) {
    return str.replace(/-/g, '');
  }
}

contracts.filters.add('stripSlashes', function(str) { return str.replace(/-/g, ''); });
schema = {
  type: 'string',
  filter: contracts.filters.stripSlashes().trim()
}

Custom formats

contracts.formats.add('ssn', function(str) {
  // TODO: Validate that str is a ssn.
  return true;
});

var schema = {
  type: 'string',
  format: 'ssn'
}

License

(The MIT License)

Copyright (c) 2011 Eirikur Nilsson <eirikur@nilsson.is>

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.