configuration-validator

Configuration Validator

Built as the pluggable validator for webpack-validator but could be used to validate any configuration object.

Usage

var configValidator = require('configuration-validator')

// call the function with your config and validators
configValidator('Name of config', config, arrayOfValidators)

Validators

A validator is an object that describes to configuration-validator what it should run on and defines a function to run to do the validation. Here's an example of a simple validator that checks for the value to be a boolean:

{
  key: 'foo.bar', // can be any depth. Uses lodash's `get` method
  description: 'Some descriptive message', // used in verbose mode (in development)
  validate: function validateFooBar(value, context) {
    // value is the value of `foo.bar` for the given object
    // context is an object with the following properties:
    //   - `key` - `foo.bar` in this case
    //   - `parent` - the parent object in which this value is found
    //   - `config` - the entire object being validated

    if (typeof value !== 'boolean') {
      // if it's not a boolean, then we fail the validation. In this case
      // we return a message that is an error or a warning
      return 'must be a boolean' // just shorthand for: {error: 'must be a boolean'}
      // or you can do:
      // return {warning: 'must be a boolean'} // output is yellow
      // return {error: 'must be a boolean'} // output is red
    }
  },
}

Uncovered Path Validation

One handy feature of the configuration-validator is that it will warn if your object has a path that's not covered by validation keys. For example, consider the following config:

// config
const config = {
  bar: {
    foo: true,
    foobar: 2,
  },
  baz: 32,
}

There are three paths associated with this config object: bar.foo, bar.foobar, and baz.

Given the following validators:

const validators = [
  {key: 'bar.foo', validate() {}},
  {key: 'baz', validate() {}},
]

You will get a warning indicating that bar.foobar is an uncovered path (meaning it's not validated).

To cover all paths, you could simply add a validotor for bar.foobar or add a validator for the entire bar path like so:

const validators = [
  {key: 'bar', validate() {}},
  {key: 'baz', validate() {}},
]

One issue you might have with this is currently you lose the deep path check because the entire object is considered to be covered. So, if you were to misspell the foo property, you wouldn't get the warning.

Catching misspellings is the biggest benefit of the uncovered path validation feature, so it's normally best to try to avoid doing validation on entire objects if possible and try to validate privitives and arrays only.

LICENSE

MIT