GraphQL Code Generator lets you generate code from a GraphQL schema. It is commonly used to create Typescript types to ensure the consuming program agrees with the data it is receiving.

Fast-check is a Property Testing framework for Typescript / Javascript. It allows testing properties of a program using arbitrarily generated data. Fast-check uses Arbitrarys to create data, that is, descriptions of the data we need to create.

Say we have this datatype...

// our datatype
interface Person {
  name: string;
  age: number;
}

...the arbitrary would look like:

import * as fc from "fast-check";

const personArbitrary = fc.record({
  name: fc.string(),
  age: fc.integer()
});

This can then be used in property tests or as generators to create sample test data.

This library is a plugin for GraphQL Code Generator that creates fast-check Arbitrarys for your schema data types.

ahem