json-to-runtypes

Convert JSON into runtypes capable of
parsing the same JSON shape.

Example

Given some JSON from a made up blog JSON API, we can generate runtypes that can
parse those JSON replies:

``javascript
import { jsonToRuntypes } from 'json-to-runtypes';

const json = {
title: 'my blog',
posts: [
{
title: 'first!',
id: 1,
published: true,
author: {
name: 'Rune',
id: 1,
},
},
{
title: 'second',
id: 2,
slug: 'post-the-second',
author: {
name: 'Frank',
id: 2,
avatarSrc: 'https://example.org/avatar.png',
},
},
],
links: {
totalPages: 3,
currentPage: 2,
self: 'https://example.org/2',
next: 'https://example.org/3',
prev: 'https://example.org/1',
},
};

const typescript = jsonToRuntypes(json);

console.log(typescript);
`

The generated TypesScript code looks like this:

`typescript
import * as rt from 'runtypes';

const AuthorRt = rt.Intersect(
rt.Record({ name: rt.String, id: rt.Number }),
rt.Record({ avatarSrc: rt.String }).asPartial(),
);

type TAuthor = rt.Static;

const PostsRt = rt.Intersect(
rt.Record({ title: rt.String, id: rt.Number, author: AuthorRt }),
rt.Record({ published: rt.Boolean, slug: rt.String }).asPartial(),
);

type TPosts = rt.Static;

const LinksRt = rt.Record({
totalPages: rt.Number,
currentPage: rt.Number,
self: rt.String,
next: rt.String,
prev: rt.String,
});

type TLinks = rt.Static;

export const RootRt = rt.Record({
title: rt.String,
posts: rt.Array(PostsRt),
links: LinksRt,
});

export type TRoot = rt.Static;
`

Using the command line

`shell
▶ npx json-to-runtypes --help

Usage: json-to-runtypes [options]

Convert JSON into Runtypes capable of parsing the same JSON shape.

Options:
-i, --input Path to JSON. Can also be stdin.
-o, --output

Output file.
h, --help display help for command

`

The command line supports pipes:

`shell
▶ cat my-json-file.json | npx json-to-runtypes -o my-types.ts
``