@waynevanson/generator

Generate data using simple stuctures and beautiful combinators.

Installation

``sh
npm install @waynevanson/generator
yarn add @waynevanson/generator
pnpm add @waynevanson/generator
`

Quickstart

`ts
import * as gen from "@waynevanson/generator"

interface Person {
name: string
age: number
friendly: boolean
// some people don't have eyes due to accidents and some could be albino
eyes?: "green" | "hazel" | "brown" | "blue" | "red"
foods: Array
}

interface Food {
name: string
category: string
}

const name = gen
.tuple([
gen.constants(["james", "gregory"]),
gen.constants(["bond", "house"]),
])
.map(([first, last]) => [first, last].join(" "))

const person = gen.intersect([
gen.required({
name,
age: gen.integer({ min: 0, max: 100 }),
friendly: gen.boolean,
// we can use generators that are not yet defined using the lazy combinator
foods: gen.array(
gen.lazy(() => food),
{ min: 1, max: 2 }
),
}),
gen.partial({
eyes: gen.constants(["green", "hazel", "brown", "blue", "red"]),
}),
])

// defined after person.foods
const food = gen.constants(["sultanas", "apricot", "wheat"])

const people = gen.array(person, { min: 5, max: 5 })

// 0 <= seed < (2**32)
const data = people.run(0)

console.log(JSON.stringify(data, null, 2))
`

The above prints the following:

`json
[
{
"name": "james house",
"age": 67,
"friendly": true,
"foods": ["apricot", "apricot"],
"eyes": "blue"
},
{
"name": "gregory house",
"age": 89,
"friendly": false,
"foods": ["sultanas", "apricot"],
"eyes": "brown"
},
{
"name": "gregory bond",
"age": 25,
"friendly": true,
"foods": ["apricot"]
},
{
"name": "james bond",
"age": 2,
"friendly": true,
"foods": ["apricot"],
"eyes": "green"
},
{
"name": "gregory house",
"age": 23,
"friendly": true,
"foods": ["sultanas", "sultanas"]
}
]
``

Docs

Please visit the code for more information.
The code has docs and the code examples are the tests.

Upcoming

- Distribution options for all applicable generators (about half are done)
- Use new distrubtion pattern for integer values
- 100% test coverage and carefully considered tests
- Generated documents from code