strongly-typed

Strongly-typed JavaScript objects, self-validating, with detailed error reports.

Support

IE9+ and everything else (same support as Object.create)

Usage

var TypeName = stronglyTyped(interface_definition, [prototype], [allowUnspecifiedFields])

interface_definition is a plain object of the expected structure with fields containing strings to match typeof in the typed objects. Additionally those strings can be prefixed with question mark ? to make them optional. If the field exist and is not null, it will be checked against the type.

You can also use null or empty {} to indicate that the field must exist, without specifying anything else about it.

You can also use [] to enforce field being an array (as typeof retrns "object" for arrays).

Example

var Person = stronglyTyped({
    "name": {
        first:"string",
        last:"string",
        middle:"?string"
    },
    "age": "number",
    "phoneNumber": "?string"
    "favorites": []
})

//create instance
var joe = Person({
    "name": {
        first:"Joe",
        last:"Average"
    },
    "age": 52,
    // "phoneNumber": null, or not defined at all
    "favorites": ["beer","game"]
})

//check type
Person.created(joe) === true

If [] is left empty in description, inner elements of the array are not validated. If there is first element in the array description, it's treated as schema for each element inside the array. Additional elements in description are omitted.

Example - array deep validation

var Person2 = stronglyTyped({
    "name": "string",
    "favorites": [
        {
            "id": "number",
            "value": "string"
        }
    ]
})

//create instance
var moe = Person2({
    "name": "Moe Average"
    "favorites": [
        { "id": 1, "value": "beer" },
        { "id": 2, "value": "game" }
    ]
})

//check type
Person2.created(moe) === true

More examples in tests/index.js

No new keyword

Strongly typed objects are factories, not classes. Because it's better that way. See: https://medium.com/javascript-scene/how-to-fix-the-es6-class-keyword-2d42bb3f4caf