Validate RC
A library that validates objects with rules.
# Usage
**NOTE: This library is intended to be used for config files, but if you __really__ want to, you can use it like a 'runtime interface'.**
__Example__
```ts
// dummy.ts
// import validateRc
import validateRc, { Optional, Choice } from 'validate-rc'
// the rules that the rc should follow
// rule to validate a custom package.json
const rules = {
name: String,
version: String,
description: Optional(Object),
scripts: Optional(Object),
keywords: Array,
dependencies: Optional(Object),
devDependencies: Optional(Object),
author: String,
license: String,
bin: Optional(Object),
repository: Optional({
type: String,
url: String
})
}
validateRc(rules, require('./package.js'))
```
## `validateRc(rules: object, rc: object): boolean | never`
Takes two objects, `rules` and `rc`. `rules` is the object that holds the rules, `rc` is the object that needs to be validated.
### Syntax
The `rules`' syntax is made of constructors and branches.
Example:
```js
const rules = {
// only matches numbers
num: Number,
// only matches strings
str: String,
// only matches booleans
bool: Boolean
// this is valid for all primitives, promises, buffers etc cannot be used
branch: {
// other constructors
}
}
```
## Optional
`Optional` is a function that accepts a constructor or branch. If in the config file the key associated with `Optional` isn't present, it does not throw. But, if that key is present and it violates the rule that is specified in `Optional`, throws.
Example
```ts
import validateRc, { Optional } from 'validate-rc'
const rules = {
age: Optional(Number),
otherInfo: Optional({
hobbies: Array,
height: Number,
name: String
})
}
validateRc(rules, {}) // does not throw, because `age` and `otherInfo` are optional
validateRc(rules, { age: 24 }) // does not throw, because `otherInfo` is optional
validateRc(rules, { // does not throw, because `otherInfo`'s rules are not violated
otherInfo: {
hobbies: [ 'Programming' ],
height: 179,
name: 'Michael'
}
})
validateRc(rules, { // throws, because `age` is a string
age: 'string'
})
validateRc(rules, { // throws, because `otherInfo`'s rules are violated
otherInfo: {}
})
validateRc(rules, { // throws, because otherInfo is a boolean and not an object
otherInfo: false
})
```
## Choice
`Choice` is a function that takes multiple arguments as choices, throws when the value in the config isn't present in `Choice`.
Example
```ts
import validateRc, { Optional, Choice } from 'validate-rc'
const rule = { esVersion: Optional(Choice('es5', 'es6', 'es2015', 'esnext')) }
validateRc(rule, {}) // does not throw, because its optional
validateRc(rule, { esVersion: 'es6' }) // does not throw, because 'es6' is in `Choice`
validateRc(rule, { esVersion: 'es2017' }) // throws, because 'es2017' isn't in `Choice`
```