Runtypes-generate NPM

Runtypes-generate

Runtypes-generate convert runtypes type to jsverify arbitrary.

Background

Property-based testing is very awesome approach for analyze and verification program. But this approach requires the writing of generators for all datatypes in our program. This process is very time-consuming, error-prone and not DRY.

Example:

import { Number, Literal, Array, Tuple, Record } from 'runtypes'
const AsteroidType = Record({
    type: Literal('asteroid'),
    location: Tuple(Number, Number, Number),
    mass: Number,
})

const AsteroidArbitrary = jsc.record({
    type: jsc.constant('asteroid'),
    location: jsc.tuple(jsc.number, jsc.number, jsc.number),
    mass: jsc.number
})

But with runtypes-generate we can get AsteroidArbitrary from AsteroidType:

import { makeJsverifyArbitrary } from 'runtypes-generate'
const AsteroidType = Record({
    type: Literal('asteroid'),
    location: Tuple(Number, Number, Number),
    mass: Number,
})
const AsteroidArbitrary = makeJsverifyArbitrary(AsteroidType)

Install

npm install --save runtypes-generate

Usage

API

makeJsverifyArbitrary(type: Reflect): jsc.Arbitrary<any> - convert runtypes to jsverify arbitrary
addTypeToRegistry(tag: string, (x:Reflect) => jsc.Arbitrary<any>): void - add new generator for Constraint type with tag in args attribute
addTypeToIntersectRegistry(tags: string[], generator: (x: Reflect) => jsc.Arbitrary<any>): void) - add new generator for Intersect or custom Constraint types. TODO example
generateAndCheck(rt: Reflect, opts?: jsc.Options): () => void - run jsc.assert for property rt.check(generatedData) for all generatedData obtained from makeJsverifyArbitrary(rt). Uses for verification custom generators for custom Constraint type. See example in tests.