ᯓ𝘁𝗿𝗮𝘃𝗲𝗿𝘀𝗮𝗯𝗹𝗲/𝘀𝗰𝗵𝗲𝗺𝗮-𝗰𝗼𝗱𝗲𝗰

Re-use your @traversable/schema to derive a bi-directional codec

 

 

 

 

 

 

 

Overview

- Instructions: to install the .codec method on all schemas, all you need to do is import @traversable/schema-codec.
- To create a covariant codec (similar to zod's .transform), use .codec.pipe
- To create a contravariant codec (similar to zod's .preprocess), use .codec.extend (WIP)

$3

Play with this example in the TypeScript playground.

``typescript
import { t } from '@traversable/schema'
import '@traversable/schema-codec'
// ^^ this installs the .pipe and .extend methods on all schemas

let User = t
.object({ name: t.optional(t.string), createdAt: t.string }).codec // <-- notice we're pulling off the .codec property
.pipe((user) => ({ ...user, createdAt: new Date(user.createdAt) }))
.unpipe((user) => ({ ...user, createdAt: user.createdAt.toISOString() }))

let fromAPI = User.parse({ name: 'Bill Murray', createdAt: new Date().toISOString() })
// ^? let fromAPI: Error | { name?: string, createdAt: Date}

if (fromAPI instanceof Error) throw fromAPI
fromAPI
// ^? { name?: string, createdAt: Date }

let toAPI = User.encode(fromAPI)
// ^? let toAPI: { name?: string, createdAt: string }
``