appgyver / ag-types

Arbitrary data structure validation for Javascript

ag-types - arbitrary data structure validation for Javascript

You've got incoming JSON data that you'd like to access using Javascript, but you can't be sure its structure matches what you expect. ag-types allows you to validate the structure of the input graph before you crash and burn on a TypeError: 'undefined' is not an object.

Installation

npm install ag-types

Usage

Examples in Coffeescript.

Describe your type

{ Object, String, Optional, Map, Any } = require 'ag-types'
RequestType = Object {
  url: String
  method: String
  params: Optional Map Any
}

Construct a type validator by simply mirroring the structure of what you want.

Validate input data against the type

input = {
  url: 'http://example.com'
}
RequestType(input)

Your validator is a function that returns a data.validation.

Continue off the validation result

RequestType(input).fold(
  (errors) -> console.log "This doesn't look like a valid request: ", errors
  (request) -> doRequest request
)

If an error occurs, the errors object will hold details of what went wrong. Otherwise you're good to go with the data.

Development

npm install
grunt test watch:test --force