tassert

High quality runtime assertions for Typescript

Usage no npm install needed!

<script type="module">
  import tassert from 'https://cdn.skypack.dev/tassert';
</script>

README

tassert

High quality runtime assertions for Typescript

Alpha - ready for feedback

Installation

npm install -S tassert

Usage

import t, {boolean, literal, number, or, string} from 'tassert'

t(number, 42)
t(string, 'foo')
t(or(boolean, number, string), 999)
t(literal([1,2,3]), [1,2]) // Error!

Features

Native types
- Array
  - Array<any>
  - Array<A>
- ArrayBuffer
- Boolean
- Buffer
- Date
- Error
- Function
- Map
  - Map<any, any>
  - Map<A, B>
- NaN
- Null
- Number
- Object
  - Object<any, any>
  - Object<A, B>
- RegExp
- Set
  - Set<any>
  - Set<A>
- String
- Symbol
- TypedArray
- Undefined
- WeakMap
  - WeakMap<any, any>
  - WeakMap<A, B>
- WeakSet
  - WeakSet<any>
  - WeakSet<A>
Constructors (tassert.instanceOf(Foo))
Literals
- Shallow (tassert.literal(42, false))
- Deep (tassert.literal(42))
Logic
- and (tassert.and(tassert.literal(42), tassert.number))
- or (tassert.or(tassert.string, tassert.number, tassert.array))
- not (tassert.or(tassert.string, not(tassert.string('foo'))))
- xor (tassert.xor(tassert.literal(42), tassert.number))
Comparators
- ==
- >
- <
- >=
- <=
- :> (Superset of)
- <: (Subset of)
- ~= (Structurally equal)

Tests

npm test

Building

npm run build

Hacking

npm run watch & npm run tdd